Re: [LAD] Attenuation of sounds in 3D space
On Fri, 2010-07-23 at 08:51 +0200, Ralf Mardorf wrote: > On Fri, 2010-07-23 at 01:09 +0200, Jörn Nettingsmeier wrote: > > On 07/22/2010 08:42 PM, Ralf Mardorf wrote: > > > > > As an ape (of course I'm an ape like every human is an ape) and troll (I > > > don't see myself as a troll) I suspect phasing too, that's why I > > > overstated argued with the next generation Cochlea-Implant, or needles > > > in the brain. > > > > that is a bogus statement. phasing happens in the brain as well. just > > put on your favourite pair of headphones and wire one side out-of-phase. > > instant nausea. (of course, if you keep it on for a few days, your brain > > will adapt - presto: you'll be hurling all over the real world when you > > finally put them down.) > > > > > Visual 3D, by a surround projection + 3D glasses isn't perfect, but > > > there is just one picture and not several pictures that needs to be > > > phase synced in the eye. Perhaps a week analogy. > > > > a terribly chosen analogy indeed. since when do the eyes care what phase > > an incoming photon is? unless you're staring into a laser, each photon > > will have totally random phase. > > next error: there *are* two images, and they do need to be synced. phase > > is irrelevant, though. > > That's the problem with this analogy. We have two eyes and ears, but > most people have better trained eyes, so most people 'see' differences, > but less people 'hear' differences. > > > > > > When having 4 or 8 or more speakers I fear phasing at the position of > > > the ears. But perhaps it isn't that much. I'll try to listen to > > > ambisoncs :). > > > > you can get terrible phasing, and not just in the center, but pretty > > much everywhere. that's why some people stagger the timings of the > > loudspeakers a bit, to smear out the phasing until it is more or less > > masked by the content. > > but it should be noted that stereo has the very same problem. > > As I mentioned before, it's hard to do a good stereo mix, even when the > speakers are perfectly set up. When you play music on radio, you need to > check the phases of the recordings, because there are a lot of bad > recordings. I guess it becomes harder the more channels you need to > control. PS: Not only because of the position of the speakers, but started with the recoding, resp. master mix, that's why ... > > > now if > > method A produces a 60° soundstage with phasing at N units of > > obnoxiousness, a method that produces 360° surround is entitled to 6N > > UoO phasing. in practice, ambisonics does better than this, but there is > > no denying the issue. > > one thing that often gets overlooked: people have learned to accept > > stereo (or, in some circles, 5.1) as the gold standard, and its > > shortcomings have grown into desired features. it's very hard to compete > > with a method that does a few things very well and doesn't even try to > > reproduce most of the auditory cues of, say, a live experience. > > Correct, I like stereo, I don't like 5.1 and indeed stereo is very > limited, but with some training it's good to handle. > If ambisonics shouldn't have the disadvantages of 5.1 I might like it. > It's funny, regarding to the German Wiki ambisonics is as old as I'm. > > > the main ingredient that makes any sound reproduction system sound good > > is your brain. the trick is to nudge it into sympathy with carefully > > chosen cues. ...: > Btw. I 'try' to do stereo mixes that do sound mono as near as possible > to the stereo mix and mono could be two channels as one or just one of > the two channels. So I limit stereo to a special functionality, but > don't use all capabilities. This could be called 'broadcasting > behaviour'. I know that I need to break this habit for surround sound, > but when listening and unfortunately working with 5.1, I didn't like it. > > Btw. even some consumers don't like 5.1, but perhaps because they set up > the speakers completely bad. IIUC they hardly could set up the speakers > completely bad, if they would use ambisonics. IIUC for large rooms there > are many speakers needed, perhaps this is the reason that shit like 5.1, > Dolby surround, Dolby stereo is common. OT: For film on cord Dolby > stereo anyway is nice for stereo, without Dolby there's hardcore wow and > flutter ... hm, regarding to wiki it's called dolby digital, doesn't > matter German filmmakers usually can't pay for Dolby. > > Thanx for the information :) > > Ralf ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Fri, 2010-07-23 at 01:09 +0200, Jörn Nettingsmeier wrote: > On 07/22/2010 08:42 PM, Ralf Mardorf wrote: > > > As an ape (of course I'm an ape like every human is an ape) and troll (I > > don't see myself as a troll) I suspect phasing too, that's why I > > overstated argued with the next generation Cochlea-Implant, or needles > > in the brain. > > that is a bogus statement. phasing happens in the brain as well. just > put on your favourite pair of headphones and wire one side out-of-phase. > instant nausea. (of course, if you keep it on for a few days, your brain > will adapt - presto: you'll be hurling all over the real world when you > finally put them down.) > > > Visual 3D, by a surround projection + 3D glasses isn't perfect, but > > there is just one picture and not several pictures that needs to be > > phase synced in the eye. Perhaps a week analogy. > > a terribly chosen analogy indeed. since when do the eyes care what phase > an incoming photon is? unless you're staring into a laser, each photon > will have totally random phase. > next error: there *are* two images, and they do need to be synced. phase > is irrelevant, though. That's the problem with this analogy. We have two eyes and ears, but most people have better trained eyes, so most people 'see' differences, but less people 'hear' differences. > > > When having 4 or 8 or more speakers I fear phasing at the position of > > the ears. But perhaps it isn't that much. I'll try to listen to > > ambisoncs :). > > you can get terrible phasing, and not just in the center, but pretty > much everywhere. that's why some people stagger the timings of the > loudspeakers a bit, to smear out the phasing until it is more or less > masked by the content. > but it should be noted that stereo has the very same problem. As I mentioned before, it's hard to do a good stereo mix, even when the speakers are perfectly set up. When you play music on radio, you need to check the phases of the recordings, because there are a lot of bad recordings. I guess it becomes harder the more channels you need to control. > now if > method A produces a 60° soundstage with phasing at N units of > obnoxiousness, a method that produces 360° surround is entitled to 6N > UoO phasing. in practice, ambisonics does better than this, but there is > no denying the issue. > one thing that often gets overlooked: people have learned to accept > stereo (or, in some circles, 5.1) as the gold standard, and its > shortcomings have grown into desired features. it's very hard to compete > with a method that does a few things very well and doesn't even try to > reproduce most of the auditory cues of, say, a live experience. Correct, I like stereo, I don't like 5.1 and indeed stereo is very limited, but with some training it's good to handle. If ambisonics shouldn't have the disadvantages of 5.1 I might like it. It's funny, regarding to the German Wiki ambisonics is as old as I'm. > the main ingredient that makes any sound reproduction system sound good > is your brain. the trick is to nudge it into sympathy with carefully > chosen cues. Btw. I 'try' to do stereo mixes that do sound mono as near as possible to the stereo mix and mono could be two channels as one or just one of the two channels. So I limit stereo to a special functionality, but don't use all capabilities. This could be called 'broadcasting behaviour'. I know that I need to break this habit for surround sound, but when listening and unfortunately working with 5.1, I didn't like it. Btw. even some consumers don't like 5.1, but perhaps because they set up the speakers completely bad. IIUC they hardly could set up the speakers completely bad, if they would use ambisonics. IIUC for large rooms there are many speakers needed, perhaps this is the reason that shit like 5.1, Dolby surround, Dolby stereo is common. OT: For film on cord Dolby stereo anyway is nice for stereo, without Dolby there's hardcore wow and flutter ... hm, regarding to wiki it's called dolby digital, doesn't matter German filmmakers usually can't pay for Dolby. Thanx for the information :) Ralf ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, 2010-07-22 at 23:53 +0200, Philipp Überbacher wrote: > Excerpts from fons's message of 2010-07-22 23:24:24 +0200: > > On Thu, Jul 22, 2010 at 01:56:41PM -0700, James Warden wrote: > > > > > > This is > > > > probably closer to the object size comparison. > > > > I wonder how well we can judge something like twice the > > > > brightness. > > > > > > or smelling a perfume twice stronger :) > > > > A very nice analogy, taking us even deeper into fuzzy territory... > > > > > It reminds me a little about intensive and extensive variables > > > in physics. That may well be unrelated though ... > > > > I don't think it is directly related to that particular > > difference. But it certainly is related to a more general > > form of it - seeing each 'unit' in its own domain, and > > some domains being fully isolated from others. > > > > We all agree on what 'red' means. Because we have learned > > the meaning of that word by association. But do we 'see' > > the same thing ? AFAIK, that is impossible to verify. > > > > Ciao, > > > > -- > > FA > > This however is a thing I did wonder about. The general question of > whether perception is the same for every human, whether colors are the > same and so on. It most likely is hard to impossible to verify, but I > have to assume it is at least similar. It's a very nice question for > sure. Most people have the same emotions, e.g. red = warm, blue = cold, even if others might 'see' red as green instead of red. Btw. for colours there were made tests, at what point the smallest visible difference to the 'next' nuance is. The question about the colour is often asked by children, at least by gifted children. And indeed we need to learn how the colours are named. We much earlier have an impression of twice as loud, perhaps we need to learn this too, but I guess most people, me too, don't remember that this happened. We do know what 'twice as' is, before we know what fractional arithmetic is. In fact people do think different, simplified there are right and left brained thinking people, artists often are left-hander, dyslexics etc., also there is the difference between people who think 'verbal' or 'nonverbal' e.g. by colours. But emotions are most of the times equal, even thoughts are most of the times equal. How often do we read something on a mailing list and did thought the same? We can assume that our brains 'see' 'red' as similar the same colour. And most of us will 'hear' twice as loud for 'usual' loudness and 'usual' music, speech around 10dB, but e.g. 6dB, even if 6dB is measurable for twice as near to a sound source, IIRC. For children it's natural to think about, that other people might see colours etc. very different, for adults this is more common for people who guess that they are much different than other people. Most of us IQ 80 or IQ 140 do have the same impressions, not the same interests and taste, but yes, red seems to be red and twice as loud seems to be twice as loud for most of us. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On 07/22/2010 08:42 PM, Ralf Mardorf wrote: As an ape (of course I'm an ape like every human is an ape) and troll (I don't see myself as a troll) I suspect phasing too, that's why I overstated argued with the next generation Cochlea-Implant, or needles in the brain. that is a bogus statement. phasing happens in the brain as well. just put on your favourite pair of headphones and wire one side out-of-phase. instant nausea. (of course, if you keep it on for a few days, your brain will adapt - presto: you'll be hurling all over the real world when you finally put them down.) Visual 3D, by a surround projection + 3D glasses isn't perfect, but there is just one picture and not several pictures that needs to be phase synced in the eye. Perhaps a week analogy. a terribly chosen analogy indeed. since when do the eyes care what phase an incoming photon is? unless you're staring into a laser, each photon will have totally random phase. next error: there *are* two images, and they do need to be synced. phase is irrelevant, though. When having 4 or 8 or more speakers I fear phasing at the position of the ears. But perhaps it isn't that much. I'll try to listen to ambisoncs :). you can get terrible phasing, and not just in the center, but pretty much everywhere. that's why some people stagger the timings of the loudspeakers a bit, to smear out the phasing until it is more or less masked by the content. but it should be noted that stereo has the very same problem. now if method A produces a 60° soundstage with phasing at N units of obnoxiousness, a method that produces 360° surround is entitled to 6N UoO phasing. in practice, ambisonics does better than this, but there is no denying the issue. one thing that often gets overlooked: people have learned to accept stereo (or, in some circles, 5.1) as the gold standard, and its shortcomings have grown into desired features. it's very hard to compete with a method that does a few things very well and doesn't even try to reproduce most of the auditory cues of, say, a live experience. the main ingredient that makes any sound reproduction system sound good is your brain. the trick is to nudge it into sympathy with carefully chosen cues. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On 07/22/2010 08:15 PM, Gene Heskett wrote: 1. How are the signals brought into phase such that electronically, all mic ribbons or diaphragms seem to occupy the same space, just facing in different directions? well, you can't do that :) two approaches: if you only care for horizontal surround (and there is no significant z axis content), you can stack an omni and two fig8s on top of one another, so that they are in phase for signals arriving along the horizontal plane. this is often called the nimbus-halliday array, after the guy that introduced it at nimbus records. sounds very good, but no height. if you do want height, place 4 sub-cards or cardiods as close together as possible, arranged on the faces of a tetrahedron. then with some clever filtering, you can get very good results, and the comb filtering at hf can be worked around with a slight treble boost. comb filtering at hf looks worse than it sounds, usually. And of course the same concern comes into play at the speakers since they are generally placed around the listener which in no way approximates the nearly single point reception these mics will hear. that's not the point. the idea is this: you measure the soundfield in one spot, and you aim to reproduce it in this one spot only (that's the maths). so the speakers should be really really close together. the good thing is: it also works when the speakers are far apart, which means we get room for listeners :) the interesting aspect of first-order ambisonics is not how it works (it only works in a point volume, which is not terribly useful), but how gracefully it fails outside this volume. In my own mind, the placement of a PZ microphone in each of the places one would place the playback speakers would seem to be a superior method, at least for a listener sitting in the nominal center, who will be so overwhelmed by (supposedly not important sonically we are told) the phasing errors that he cannot single out a single largest cause for the lack of realism. it might seem so, but in practice it does not really work. say you have a regular hexagon of microphones, with a radius of 2m. assume that a singer is standing at the "north" mike. sound reaches this mike instantaneously. it takes about 12ms to reach the south mike. that is a comb filter that reaches way down where it makes the sound tinny, unpleasant, and worst of all, unrepairable. and consider what the effect during playback would be: loud, correct sound from north speaker after 6ms, bogus echo from south speaker after 18ms, combining into coloration, giving a wrong spatial cue of a back wall that isn't there, yet arriving too soon for the brain to be able to separate it as a bogus event and throw it away. the fun thing is, if you had several thousand microphones (and speakers), the results would be excellent. but before shouldering the expenses, you might be tempted to cut some corners. ambisonics is a very usable shortcut imho. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On 07/22/2010 05:02 PM, f...@kokkinizita.net wrote: Such a 'virtual stereo mic' is part of Tetraproc, and there's also a Ladspa plugin doing this. The latter has some problems in Ardour as it has 4 ins and 2 outs, and Ardour get confused by this and will (IIRC) copy inputs 3 and 4 to the outputs while it shouldn't do that. ardour always does that. it's consistent (but wrong imho) and nothing to do with the vmic plugin. when you use the plugin in a bus with 4 ins and 2 outs, everything works as expected. if you find such busses confusing, an alternative is to use a 4 in 4 out bus and leave outputs 3 and 4 unconnected. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 03:09:13PM -0700, James Warden wrote: > I do think it has something to do with intensive vs extensive in the > following way: > > when we talk about sound waves, temperature, smell, brightness, etc, these > are macro-observables representing a statistically huge number of > micro-states. This is how our human senses make sense of these huge sets (cf. > statistical physics founded by Boltzmann that explains classic > thermodynamics). It is therefore difficult for our brain to strictly quantify > variations of these huge sets that our senses can only approach "roughly" by > statistical "reduction". > > On the other hand, any discreet observable that our senses can reach directly > (e.g. volume of an object of the same size order as our own body) is easily > quantifiable. > > Just a guess ... I need to think about this... It's 00:20 here, so that will be for toworrow. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 11:49:03PM +0200, Philipp Überbacher wrote: > Interesting idea. From the little I read about masking it is a complex > thing as well, frequency, SPL, time between sounds, all that and > possibly more matters. Which makes perceptual coding an interesting domain... > We could think about what makes judging twice the > loudness more difficult and maybe find a relation to another phenomenon > this way. The limits of hearing apply to everything, but what about > factors like the time between two sounds or the length of the sounds? All of these affect both masking and loudness. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
> > It reminds me a little about intensive and extensive > variables > > in physics. That may well be unrelated though ... > > I don't think it is directly related to that particular > difference. But it certainly is related to a more general > form of it - seeing each 'unit' in its own domain, and > some domains being fully isolated from others. > I do think it has something to do with intensive vs extensive in the following way: when we talk about sound waves, temperature, smell, brightness, etc, these are macro-observables representing a statistically huge number of micro-states. This is how our human senses make sense of these huge sets (cf. statistical physics founded by Boltzmann that explains classic thermodynamics). It is therefore difficult for our brain to strictly quantify variations of these huge sets that our senses can only approach "roughly" by statistical "reduction". On the other hand, any discreet observable that our senses can reach directly (e.g. volume of an object of the same size order as our own body) is easily quantifiable. Just a guess ... J. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 02:57:36PM -0700, James Warden wrote: > > We all agree on what 'red' means. Because we have learned > > the meaning of that word by association. But do we > > 'see' > > the same thing ? AFAIK, that is impossible to verify. > > I would tend to say yes, for if I was in your brain to check, I would be you > :) Touché. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thursday 22 July 2010 17:24:24 f...@kokkinizita.net wrote: > We all agree on what 'red' means. Because we have learned > the meaning of that word by association. But do we 'see' > the same thing ? AFAIK, that is impossible to verify. Been asking people the above at least since I was a youngish teenager. here is another to go along with sound, light, and smell... Is some pepper dish twice as hot as another? drew ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
> We all agree on what 'red' means. Because we have learned > the meaning of that word by association. But do we > 'see' > the same thing ? AFAIK, that is impossible to verify. I would tend to say yes, for if I was in your brain to check, I would be you :) J. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 10:37:23PM +0100, Folderol wrote: > On Thu, 22 Jul 2010 23:24:24 +0200 > f...@kokkinizita.net wrote: > > > We all agree on what 'red' means. Because we have learned > > the meaning of that word by association. But do we 'see' > > the same thing ? AFAIK, that is impossible to verify. > > This brings back memories of long arguments amongst my friends (when > we were all young and spotty). > > We thought we'd pinned it down when someone suggested that the only way > to be sure, would be if humans developed telepathy - a whole 'nother > arguing point :) > > That got shot down when someone suggested that the brain would have to > do some form of translation to telepathic 'waves' and how could we be > sure that everyone would translate the same way :) Yes. This was pointed out by Wittgenstein some 0.75 centuries ago - you can't prove consciousness. Even if you torture someone and he's screaming like hell, you can always say "it's a robot progranmed to act like this when given the stimuli we are giving it", and there's no way to disprove that. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
Excerpts from fons's message of 2010-07-22 23:24:24 +0200: > On Thu, Jul 22, 2010 at 01:56:41PM -0700, James Warden wrote: > > > > This is > > > probably closer to the object size comparison. > > > I wonder how well we can judge something like twice the > > > brightness. > > > > or smelling a perfume twice stronger :) > > A very nice analogy, taking us even deeper into fuzzy territory... > > > It reminds me a little about intensive and extensive variables > > in physics. That may well be unrelated though ... > > I don't think it is directly related to that particular > difference. But it certainly is related to a more general > form of it - seeing each 'unit' in its own domain, and > some domains being fully isolated from others. > > We all agree on what 'red' means. Because we have learned > the meaning of that word by association. But do we 'see' > the same thing ? AFAIK, that is impossible to verify. > > Ciao, > > -- > FA This however is a thing I did wonder about. The general question of whether perception is the same for every human, whether colors are the same and so on. It most likely is hard to impossible to verify, but I have to assume it is at least similar. It's a very nice question for sure. -- Regards, Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
Excerpts from fons's message of 2010-07-22 23:13:45 +0200: > On Thu, Jul 22, 2010 at 10:50:58PM +0200, Philipp Überbacher wrote: > > > We may be comparing the wrong thing when we compare with the size of > > objects to loudness. > > Indeed. I did not mention the visual analogy to suggest > that the two domains are similar - rather to point out > they are not. Something that works for one of them does > not for the other. What I tried to say is that there might be different cases in each domain, some of which may be similar to a case in another domain. > > I wonder how well we can judge something like twice the > > brightness. > > Same problem. I gues we can't. Or that whatever value > of 'double' we arrive at will be without meaning. > > My guess so far, but I have *NO* scientific evidence at > all to support it, just some intuition, is that human > perception of loudness of a sound is somehow related to > the extent that a particular sound does prevent us to > detect other known sounds, i.e. to masking effects. > > CIao, Interesting idea. From the little I read about masking it is a complex thing as well, frequency, SPL, time between sounds, all that and possibly more matters. We could think about what makes judging twice the loudness more difficult and maybe find a relation to another phenomenon this way. The limits of hearing apply to everything, but what about factors like the time between two sounds or the length of the sounds? -- Regards, Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 04:57:41PM -0400, Paul Davis wrote: > one little side problem with this is that our sensitivity to both > loudness and brightness is adaptive. this means that although one > could do some experimental work to determine the ratios that lead most > people to judge one sound 2x as loud as another, as soon as you leave > the experimental context, it becomes pretty meaningless in any > practical sense. what you judge as quiet or loud (or bright or dim) > depends an awful lot on what you've just been listening to. given that > our sensitivity to volume is non-linear, it only takes some > pre-exposure to a very quiet or very loud environment to totally skew > the part of the curve that we're on when we try to establish how loud > something is. > > to be clear, i'm not suggesting that its not possible to come up with > some useful and interesting numbers by measuring this sort of thing. i > just want to note that they have to be viewed as deeply fuzzy because > of the effect of the pre-listening environment in setting sensitivity > levels. Absolutely true. Extrapolating a bit, that is one of the reasons why an unamplified singer in an opera theatre can have a dramatic effect that is much stronger than someone yelling into a microphone and being amplified to 130 dB SPL. By which I don't want to imply that amplified music is wrong in any sense. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, 22 Jul 2010 23:24:24 +0200 f...@kokkinizita.net wrote: > We all agree on what 'red' means. Because we have learned > the meaning of that word by association. But do we 'see' > the same thing ? AFAIK, that is impossible to verify. > > Ciao, This brings back memories of long arguments amongst my friends (when we were all young and spotty). We thought we'd pinned it down when someone suggested that the only way to be sure, would be if humans developed telepathy - a whole 'nother arguing point :) That got shot down when someone suggested that the brain would have to do some form of translation to telepathic 'waves' and how could we be sure that everyone would translate the same way :) 10 GOTO 10 -- Will J Godfrey http://www.musically.me.uk Say you have a poem and I have a tune. Exchange them and we can both have a poem, a tune, and a song. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, 2010-07-22 at 13:56 -0700, James Warden wrote: > > This is > > probably closer to the object size comparison. > > I wonder how well we can judge something like twice the > > brightness. > > -- > > or smelling a perfume twice stronger :) Because the impression of loudness is a mix of 'taste' and something that is measurable. A jackhammer might become easier double as loud as a enjoyable tune. When do we feel having sex twice as good? Measurable by hormone release? ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
lieven moors wrote: > ...continuation of truncated mail (does anyone know why this happens?) Probably it's the second "From" line; looks like your mail client is confused by this. Concerning your question: As other have remarked, that is a very intricate question which is studied in psychoacoustics, so one of the requisite textbooks on the subject (like Roederer's "Psychophysics") might be helpful. Conventional wisdom (based on psychoacoustic experiments) has it that a 10 phon increase (i.e., 10dB SPL, corrected for frequency-specific sensitivity using the Fletcher/Munson curves or some variation of that) means double loudness for many people (on the average). But of course that doesn't mean that you can just add signals until you achieve a 10 phon increase and get something twice as loud. If you're adding signals then you also have to consider masking effects (basically, spectral components hitting the same critical band on the Cochlea), so you'll need a psychoacoustic model (same as what gets used for lossy compression) to get it sorted out. Albert -- Dr. Albert Gr"af Dept. of Music-Informatics, University of Mainz, Germany Email: dr.gr...@t-online.de, a...@muwiinfa.geschichte.uni-mainz.de WWW:http://www.musikinformatik.uni-mainz.de/ag ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 01:56:41PM -0700, James Warden wrote: > > This is > > probably closer to the object size comparison. > > I wonder how well we can judge something like twice the > > brightness. > > or smelling a perfume twice stronger :) A very nice analogy, taking us even deeper into fuzzy territory... > It reminds me a little about intensive and extensive variables > in physics. That may well be unrelated though ... I don't think it is directly related to that particular difference. But it certainly is related to a more general form of it - seeing each 'unit' in its own domain, and some domains being fully isolated from others. We all agree on what 'red' means. Because we have learned the meaning of that word by association. But do we 'see' the same thing ? AFAIK, that is impossible to verify. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 10:50:58PM +0200, Philipp Überbacher wrote: > We may be comparing the wrong thing when we compare with the size of > objects to loudness. Indeed. I did not mention the visual analogy to suggest that the two domains are similar - rather to point out they are not. Something that works for one of them does not for the other. > I wonder how well we can judge something like twice the > brightness. Same problem. I gues we can't. Or that whatever value of 'double' we arrive at will be without meaning. My guess so far, but I have *NO* scientific evidence at all to support it, just some intuition, is that human perception of loudness of a sound is somehow related to the extent that a particular sound does prevent us to detect other known sounds, i.e. to masking effects. CIao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 4:50 PM, Philipp Überbacher wrote: > We may be comparing the wrong thing when we compare with the size of > objects to loudness. > It's relatively easy to say that the interval between sound B and C > is twice as long as the interval between A and B (given the > interval and the length of the sound is in a certain range). This is > probably closer to the object size comparison. > I wonder how well we can judge something like twice the > brightness. one little side problem with this is that our sensitivity to both loudness and brightness is adaptive. this means that although one could do some experimental work to determine the ratios that lead most people to judge one sound 2x as loud as another, as soon as you leave the experimental context, it becomes pretty meaningless in any practical sense. what you judge as quiet or loud (or bright or dim) depends an awful lot on what you've just been listening to. given that our sensitivity to volume is non-linear, it only takes some pre-exposure to a very quiet or very loud environment to totally skew the part of the curve that we're on when we try to establish how loud something is. to be clear, i'm not suggesting that its not possible to come up with some useful and interesting numbers by measuring this sort of thing. i just want to note that they have to be viewed as deeply fuzzy because of the effect of the pre-listening environment in setting sensitivity levels. --p ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
> This is > probably closer to the object size comparison. > I wonder how well we can judge something like twice the > brightness. > -- or smelling a perfume twice stronger :) It reminds me a little about intensive and extensive variables in physics. That may well be unrelated though ... J. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
Excerpts from fons's message of 2010-07-22 22:36:58 +0200: > On Thu, Jul 22, 2010 at 09:31:09PM +0200, lieven moors wrote: > > > Hi Fons, I'm a fool to even try to answer this question. > > But I couldn't resist... > > :-) > > > Let's suppose we have two sounds A and B, > > and sound B has been measured as being twice as loud as A, > > by somebody. In order to be able to say that, that person needs > > some kind of reference measurement unit, the equivalent of a > > measurement stick. That unit has to satisfy two requirements. > > It has to be big enough, so that people can agree some difference > > is being measured, and it has to be small enough, so that a multiples > > of that unit fit into a realistic range. There is a requirement of maximum > > precision (the smallest value we can measure), and a requirement of > > minimum precision. The question is, what kind of measurement stick > > is being used by that person. > > Not really. If A is 'twice' B, either A or B can act as the reference. > > I'm pretty sure that if you'd do the experiment to find out when > people think that an object B is twice as big as another object A > (without introducing optical illusions), you'd find that it's quite > close to a factor of 2. This is because we can easily imagine two > A's side by side, which would be 'twice as big' as one A. > Can we do something similar with 'loudness' ? As I wrote, the > only option I see is to consider two equal sources to be 'twice > as loud' as one of them, but that doesn't work out. > > Given this, what you write does make sense - there must be some > 'stick' rather than a real comparison of A to B. But what is it > based on ? If most people do agree on some value for 'twice as > loud', even with a large variation, there must be some physical > ground for this. But what is it ? And a related question: iff > there is some 'unit' even a variable one depending on frequency > etc., why can't we imagine that unit ? Why don't we 'see' the > stick ? > > > First of all, we can assume that the length of that stick will be depend > > on the range of possible input values that we observe, and that we want > > to measure. If we want to measure the size of a road, we will probably > > use kilometers, instead of meters. In the same way, when our ears want > > to measure the amplitude of a sound, our ears will use smaller or bigger > > units, depending on the ranges observed. What are the ranges we observe? > > Let's assume that humans are perfect, and observe everything that we > > can observe with SPL meters. We could do a statistical investigation > > on a number of people, and make charts of everything they hear. > > In these charts we would see what frequencies they are exposed to, > > and what the minimum and maximum SPL's are for that frequencies. > > After more analyses, we would have one chart that could be > > representative for most people. > > This is basically what has been done more than 50 years ago, with > the known results: the objective ratio corresponding to 'twice as > loud' depends on frequency, absolute level, etc. > > > From that chart we could get an estimate of the size of the measurement > > unit. Frequencies with with bigger SPL variations would be measured > > with bigger units, and visa versa. And from this we could deduce what > > the minimum precision is for a certain frequency, when we say it is twice > > as loud. To satisfy the requirement of maximum precision, we should > > take into account the smallest observable differences for every frequency > > in the spectrum. > > 'Smallest observable difference' has been measured as well. It should > relate in some way to 'twice as loud', but I haven't verified this. > OTOH, knowing the smallest observable difference does not help to > define what 'twice as loud' is supposed to be. > > Another poster mentioned that he found it quite difficult to work > out what 'twice as loud' means for him - and I do believe that is > touching on the real problem: if you start *thinking* about it > rather than just following your 'gut feeling', how sure can you > still be of your impression of 'twice as loud' ? How stable is it > in the face of doubt ? > > Keep on thinking ! We may be comparing the wrong thing when we compare with the size of objects to loudness. It's relatively easy to say that the interval between sound B and C is twice as long as the interval between A and B (given the interval and the length of the sound is in a certain range). This is probably closer to the object size comparison. I wonder how well we can judge something like twice the brightness. -- Regards, Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 09:55:40PM +0200, lieven moors wrote: > ...continuation of truncated mail (does anyone know why this happens?) No such problem here. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, Jul 22, 2010 at 09:31:09PM +0200, lieven moors wrote: > Hi Fons, I'm a fool to even try to answer this question. > But I couldn't resist... :-) > Let's suppose we have two sounds A and B, > and sound B has been measured as being twice as loud as A, > by somebody. In order to be able to say that, that person needs > some kind of reference measurement unit, the equivalent of a > measurement stick. That unit has to satisfy two requirements. > It has to be big enough, so that people can agree some difference > is being measured, and it has to be small enough, so that a multiples > of that unit fit into a realistic range. There is a requirement of maximum > precision (the smallest value we can measure), and a requirement of > minimum precision. The question is, what kind of measurement stick > is being used by that person. Not really. If A is 'twice' B, either A or B can act as the reference. I'm pretty sure that if you'd do the experiment to find out when people think that an object B is twice as big as another object A (without introducing optical illusions), you'd find that it's quite close to a factor of 2. This is because we can easily imagine two A's side by side, which would be 'twice as big' as one A. Can we do something similar with 'loudness' ? As I wrote, the only option I see is to consider two equal sources to be 'twice as loud' as one of them, but that doesn't work out. Given this, what you write does make sense - there must be some 'stick' rather than a real comparison of A to B. But what is it based on ? If most people do agree on some value for 'twice as loud', even with a large variation, there must be some physical ground for this. But what is it ? And a related question: iff there is some 'unit' even a variable one depending on frequency etc., why can't we imagine that unit ? Why don't we 'see' the stick ? > First of all, we can assume that the length of that stick will be depend > on the range of possible input values that we observe, and that we want > to measure. If we want to measure the size of a road, we will probably > use kilometers, instead of meters. In the same way, when our ears want > to measure the amplitude of a sound, our ears will use smaller or bigger > units, depending on the ranges observed. What are the ranges we observe? > Let's assume that humans are perfect, and observe everything that we > can observe with SPL meters. We could do a statistical investigation > on a number of people, and make charts of everything they hear. > In these charts we would see what frequencies they are exposed to, > and what the minimum and maximum SPL's are for that frequencies. > After more analyses, we would have one chart that could be > representative for most people. This is basically what has been done more than 50 years ago, with the known results: the objective ratio corresponding to 'twice as loud' depends on frequency, absolute level, etc. > From that chart we could get an estimate of the size of the measurement > unit. Frequencies with with bigger SPL variations would be measured > with bigger units, and visa versa. And from this we could deduce what > the minimum precision is for a certain frequency, when we say it is twice > as loud. To satisfy the requirement of maximum precision, we should > take into account the smallest observable differences for every frequency > in the spectrum. 'Smallest observable difference' has been measured as well. It should relate in some way to 'twice as loud', but I haven't verified this. OTOH, knowing the smallest observable difference does not help to define what 'twice as loud' is supposed to be. Another poster mentioned that he found it quite difficult to work out what 'twice as loud' means for him - and I do believe that is touching on the real problem: if you start *thinking* about it rather than just following your 'gut feeling', how sure can you still be of your impression of 'twice as loud' ? How stable is it in the face of doubt ? Keep on thinking ! Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On Thu, 2010-07-22 at 21:31 +0200, lieven moors wrote: > On 07/21/2010 07:24 PM, Fons Adriaensen-2 wrote: > > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > > > I think the word loudness is a problem here. Afaik it usually > > refers to > > > how it is perceived, and twice the amplitude doesn't mean twice > > the > > > perceived loudness. It may mean twice the sound pressure level, > > energy, > > > or intensity (if we ignore analogue anomalies, as you wrote in > > some other > > > answer). > > > > Subjective loudness is a very complex thing, depending on the > > spectrum, duration, and other aspects of the sound, and also > > on circumstances not related to the sound itself. > > > > For mid frequencies and a duraion of one second, the average > > subjective impression of 'twice as loud' seems to correspond > > to an SPL difference of around +10 dB. > > > > I often wondered what criterion we use to determine which > > objective SPL difference sounds as 'twice as loud'. We don't > > have any conscious numerical value (there may be unconscious > > ones such as the amount of auditory nerve pulses, or the amount > > of neural activity), so what it this impression based on ? > Sorry to post this twice, but I think the mail got truncated. > > Hi Fons, I'm a fool to even try to answer this question. > But I couldn't resist... > > Let's suppose we have two sounds A and B, > and sound B has been measured as being twice as loud as A, > by somebody. In order to be able to say that, that person needs > some kind of reference measurement unit, the equivalent of a > measurement stick. That unit has to satisfy two requirements. > It has to be big enough, so that people can agree some difference > is being measured, and it has to be small enough, so that a multiples > of that unit fit into a realistic range. There is a requirement of > maximum > precision (the smallest value we can measure), and a requirement of > minimum precision. The question is, what kind of measurement stick > is being used by that person. > > First of all, we can assume that the length of that stick will be > depend > on the range of possible input values that we observe, and that we > want > to measure. If we want to measure the size of a road, we will > probably > use kilometers, instead of meters. In the same way, when our ears want > to measure the amplitude of a sound, our ears will use smaller or > bigger > units, depending on the ranges observed. What are the ranges we > observe? > Let's assume that humans are perfect, and observe everything that we > can observe with SPL meters. We could do a statistical investigation > on a number of people, and make charts of everything they hear. > In these charts we would see what frequencies they are exposed to, > and what the minimum and maximum SPL's are for that frequencies. > After more analyses, we would have one chart that could be > representative for most people. > > >From that chart we could get an estimate of the size of the > measurement > unit. Frequencies with with bigger SPL variations would be measured > with bigger units, and visa versa. And from this we could deduce what > the minimum precision is for a certain frequency, when we say it is > twice > as loud. To satisfy the requirement of maximum precision, we should > take into account the smallest observable differences for every > frequency > in the spectrum. > > now you can kill me :-) > > Greetings, > > Lieven For microphones there usually are -10 dB pad and a lot of engineers feel around -6 dB half as loud. I guess this are usual values regarding to experiences by audio engineers. So even audio engineers can hardly say what their subjective feeling is. If you take a lot of people and you do lab tests, I guess the results will be very confusing. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
...continuation of truncated mail (does anyone know why this happens?) >From that chart we could get an estimate of the size of the measurement unit. Frequencies with with bigger SPL variations would be measured with bigger units, and visa versa. And from this we could deduce what the minimum precision is for a certain frequency, when we say it is twice as loud. To satisfy the requirement of maximum precision, we should take into account the smallest observable differences for every frequency in the spectrum. Greetings, Lieven ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] twice as loud
On 07/21/2010 07:24 PM, Fons Adriaensen-2 wrote: > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > I think the word loudness is a problem here. Afaik it usually refers to > > how it is perceived, and twice the amplitude doesn't mean twice the > > perceived loudness. It may mean twice the sound pressure level, energy, > > or intensity (if we ignore analogue anomalies, as you wrote in some > other > > answer). > > Subjective loudness is a very complex thing, depending on the > spectrum, duration, and other aspects of the sound, and also > on circumstances not related to the sound itself. > > For mid frequencies and a duraion of one second, the average > subjective impression of 'twice as loud' seems to correspond > to an SPL difference of around +10 dB. > > I often wondered what criterion we use to determine which > objective SPL difference sounds as 'twice as loud'. We don't > have any conscious numerical value (there may be unconscious > ones such as the amount of auditory nerve pulses, or the amount > of neural activity), so what it this impression based on ? Sorry to post this twice, but I think the mail got truncated. Hi Fons, I'm a fool to even try to answer this question. But I couldn't resist... Let's suppose we have two sounds A and B, and sound B has been measured as being twice as loud as A, by somebody. In order to be able to say that, that person needs some kind of reference measurement unit, the equivalent of a measurement stick. That unit has to satisfy two requirements. It has to be big enough, so that people can agree some difference is being measured, and it has to be small enough, so that a multiples of that unit fit into a realistic range. There is a requirement of maximum precision (the smallest value we can measure), and a requirement of minimum precision. The question is, what kind of measurement stick is being used by that person. First of all, we can assume that the length of that stick will be depend on the range of possible input values that we observe, and that we want to measure. If we want to measure the size of a road, we will probably use kilometers, instead of meters. In the same way, when our ears want to measure the amplitude of a sound, our ears will use smaller or bigger units, depending on the ranges observed. What are the ranges we observe? Let's assume that humans are perfect, and observe everything that we can observe with SPL meters. We could do a statistical investigation on a number of people, and make charts of everything they hear. In these charts we would see what frequencies they are exposed to, and what the minimum and maximum SPL's are for that frequencies. After more analyses, we would have one chart that could be representative for most people. >From that chart we could get an estimate of the size of the measurement unit. Frequencies with with bigger SPL variations would be measured with bigger units, and visa versa. And from this we could deduce what the minimum precision is for a certain frequency, when we say it is twice as loud. To satisfy the requirement of maximum precision, we should take into account the smallest observable differences for every frequency in the spectrum. now you can kill me :-) Greetings, Lieven ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
[LAD] twice as loud
On 07/21/2010 07:24 PM, Fons Adriaensen-2 wrote: > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > I think the word loudness is a problem here. Afaik it usually refers to > > how it is perceived, and twice the amplitude doesn't mean twice the > > perceived loudness. It may mean twice the sound pressure level, energy, > > or intensity (if we ignore analogue anomalies, as you wrote in some > other > > answer). > > Subjective loudness is a very complex thing, depending on the > spectrum, duration, and other aspects of the sound, and also > on circumstances not related to the sound itself. > > For mid frequencies and a duraion of one second, the average > subjective impression of 'twice as loud' seems to correspond > to an SPL difference of around +10 dB. > > I often wondered what criterion we use to determine which > objective SPL difference sounds as 'twice as loud'. We don't > have any conscious numerical value (there may be unconscious > ones such as the amount of auditory nerve pulses, or the amount > of neural activity), so what it this impression based on ? > > The only thing I could imagine is some link with the subjective > impression of a variable number of identical sources. For example > two people talking could be considered to be 'twice as loud' as > one. But that is not the case, the results don't fit at all (it > would mean 3 dB instead of 10). > Hi Fons, I'm a fool to even try to answer this question. But I couldn't resist... Let's suppose we have two sounds A and B, and sound B has been measured as being twice as loud as A, by somebody. In order to be able to say that, that person needs some kind of reference measurement unit, the equivalent of a measurement stick. That unit has to satisfy two requirements. It has to be big enough, so that people can agree some difference is being measured, and it has to be small enough, so that a multiples of that unit fit into a realistic range. There is a requirement of maximum precision (the smallest value we can measure), and a requirement of minimum precision. The question is, what kind of measurement stick is being used by that person. First of all, we can assume that the length of that stick will be depend on the range of possible input values that we observe, and that we want to measure. If we want to measure the size of a road, we will probably use kilometers, instead of meters. In the same way, when our ears want to measure the amplitude of a sound, our ears will use smaller or bigger units, depending on the ranges observed. What are the ranges we observe? Let's assume that humans are perfect, and observe everything that we can observe with SPL meters. We could do a statistical investigation on a number of people, and make charts of everything they hear. In these charts we would see what frequencies they are exposed to, and what the minimum and maximum SPL's are for that frequencies. After more analyses, we would have one chart that could be representative for most people. >From that chart we could get an estimate of the size of the measurement unit. Frequencies with with bigger SPL variations would be measured with bigger units, and visa versa. And from this we could deduce what the minimum precision is for a certain frequency, when we say it is twice as loud. To satisfy the requirement of maximum precision, we should take into account the smallest observable differences for every frequency in the spectrum. now you can kill me :-) Greetings, Lieven ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, 2010-07-22 at 20:22 +0200, Ralf Mardorf wrote: > On Thu, 2010-07-22 at 10:52 -0700, Fernando Lopez-Lezcano wrote: > > On Thu, 2010-07-22 at 14:01 +0200, Ralf Mardorf wrote: > > > On Thu, 2010-07-22 at 01:04 +0200, Arnold Krille wrote: > > > > We are not talking about 5.1 or 7.1 here. These suck big time. > > > > > > > > We are talking about ambisonics vs. binaurals vs. simple stereo here! > > > > > > Ok, I noticed this. > > > > > > Fon's AmbDec is the player for the files from > > > http://www.ambisonia.com/?! > > > > > > I guess a friend who lives near to my home has at least 8 outputs for an > > > Envy24 sound card and at least a JBL 5.1 setup, so the 5.1 speakers > > > could be used for a minimalist ambisonics. > > > > Yes. Fons ships an ambdec configuration for playing in a 5.1 setup (it > > is not optimal because the back speakers in a 5.1 setup are too far > > apart but it works - I use it at home). Of course it assumes that the > > 5.1 setup is correct. This link has a diagram of the speaker angles: > > > > http://de.wikipedia.org/wiki/5.1 > > > The speakers of the 5.1 system should just be used, because they are 5 > of the same type and because there are equal amps for the speakers. > There's no need to keep > http://upload.wikimedia.org/wikipedia/de/thumb/4/4e/ITUKreis_Ruhnke.jpg/300px-ITUKreis_Ruhnke.jpg, > if the speakers should really be placed correctly for 5.1 at the friends > living room at the moment. I'm not sure I understand. The 5.1 ambisonics decoder in Ambdec can decode to that arrangement and it is pretty good. You could try that before moving the speakers around. > If possible I would prefer to replace them in a way that's good for > ambisonics. > ... > IIUC 4 speakers could be set up in a quadrate with "front" at positiv-x > direction and the listener has to be in the middle of the quadrate. Yes, you could move them into a square, use only four and use the square decoder. A 5.1 setup can be used to play up to second order ambisonics, a 4 channel square can only play first order ambisonics. Most of the recordings in ambisonia.com are first order (but I think there are a few higher order as well). See this for another example of ambisonics at home: http://stackingdwarves.net/public_stuff/linux_audio/ambi_at_home/joern_nettingsmeier-ambisonics_at_home.pdf -- Fernando > Maybe there will be 8 similar speakers and amps, but regarding to the > sound card the limit is 8 channels. I guess somewhere on the ambisonics > website there will be some text and graphic about such setups. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, 2010-07-22 at 14:15 -0400, Gene Heskett wrote: > On Thursday, July 22, 2010 01:07:57 pm f...@kokkinizita.net did opine: > > > On Thu, Jul 22, 2010 at 10:35:15AM -0400, Paul Davis wrote: > > > On Thu, Jul 22, 2010 at 10:29 AM, Chris Cannam > > > > > > wrote: > > > > Question that just occurred to me. I'm very ignorant about spatial > > > > audio, and although I'm sure several of my colleagues could tell me > > > > this, I thought it might be sort of on-topic here. Is it possible, > > > > or easy, or sensible, or worthwhile, to reduce a B-format recording > > > > into stereo in multiple different ways in order to achieve > > > > different subjective "listener position" results when using > > > > headphones? > > > > > > my limited understanding is this: the B-format data encodes the > > > source position relative to some defined point in space. the decoder > > > can map the "origin" used to define the positional space however it > > > wants to. whether or not any decoders actually offer any control over > > > this is another matter. > > > > The first order B-format consists of four signals: > > > > W: equivalent to an 'omni' microphone, > > X,Y,Z: equivalent to figure-of-eight microphones > > pointing forward/back, left/right, and up/ > > down respectively. > > And interesting scenario, Fons. But it leads this simple minded broadcast > engineer with 45 years experience to ask a question. > > 1. How are the signals brought into phase such that electronically, all mic > ribbons or diaphragms seem to occupy the same space, just facing in > different directions? > > If this is not addressed, then this will lead to some interesting comb > filter effects if the signals are not kept from mixing, which they will of > course do in the ear. > > Granted, the PV of sound in normal air would require separations of inches > till the stuff above high C comes into play, but at the snares and cymbals > frequencies, I would have to assume some coloration of the sound from this > effect alone. And of course the same concern comes into play at the > speakers since they are generally placed around the listener which in no > way approximates the nearly single point reception these mics will hear. > > In my own mind, the placement of a PZ microphone in each of the places one > would place the playback speakers would seem to be a superior method, at > least for a listener sitting in the nominal center, who will be so > overwhelmed by (supposedly not important sonically we are told) the phasing > errors that he cannot single out a single largest cause for the lack of > realism. > > In my history of electronic repairs for a living over the last 60+ years, > one instance of truly hair raising realism took place when I was about 21, > and working one of the service benches at Woodburn Sound in Iowa City IA, > USA. I had bought some car parts at noon, and when I left about 6 for > dinner, I forgot & left them on the corner of the bench. Having a key to > the back door I let myself into the back door about 8, which was pretty > dark by then as only one 25 watt bulb out in the display area was on, and > half way to the door to my bench area & right in the door to the front, > display room, the Dukes of Dixieland marched by, going right over me. It > seems that Woody and Saul Marantz were out in front, had pulled a 2nd JBL > Hartzfield speaker out of Saul's econoline van, setting it just inside the > front door opposite to ours in the other front corner of the display floor, > along with a Berlant/Concertone tape deck capable of running at 15 and 30 > IPS. And the tape was the master that had cut the Dukes then current hit > record, running at 30 ips. SNR was a good 70+ db, and there was no tape > hiss audible unless you walked directly in front of the JBL 075 ring > radiator tweeters that had been added to both our Hartzfield and to the one > Saul was carrying around. No tone controls, and only a 30 watt Marantz > stereo amp., those Hartzfields were then, and may be yet, the most efficient > speakers ever made, never used more than 3 or 4 watts/channel to get SPL's > that would have done Joshua's trumpets at Jericho proud. > > Truly a total immersion in the sound, from about 35hz to nearly 30khz. > Those tweeters could do a fairly good job of reproducing a 25khz square > wave. > > It took till I had been introduced to Saul Marantz and shook hands, and for > that tape (on 14" NAB reels) to run out before the hair on the back of my > neck was truly relaxed. Saul it turned out was an endless source of > technical knowledge sprinkled with BTDT stories. And needless to say, I > did not manage to get that hydromatic transmission I had just stick shifted > back together till a day later. Yeah, I'm a JOAT. :) > As an ape (of course I'm an ape like every human is an ape) and troll (I don't see myself as a troll) I suspect phasing too, that's why I
Re: [LAD] Attenuation of sounds in 3D space
On Thu, 2010-07-22 at 10:52 -0700, Fernando Lopez-Lezcano wrote: > On Thu, 2010-07-22 at 14:01 +0200, Ralf Mardorf wrote: > > On Thu, 2010-07-22 at 01:04 +0200, Arnold Krille wrote: > > > We are not talking about 5.1 or 7.1 here. These suck big time. > > > > > > We are talking about ambisonics vs. binaurals vs. simple stereo here! > > > > Ok, I noticed this. > > > > Fon's AmbDec is the player for the files from > > http://www.ambisonia.com/?! > > > > I guess a friend who lives near to my home has at least 8 outputs for an > > Envy24 sound card and at least a JBL 5.1 setup, so the 5.1 speakers > > could be used for a minimalist ambisonics. > > Yes. Fons ships an ambdec configuration for playing in a 5.1 setup (it > is not optimal because the back speakers in a 5.1 setup are too far > apart but it works - I use it at home). Of course it assumes that the > 5.1 setup is correct. This link has a diagram of the speaker angles: > > http://de.wikipedia.org/wiki/5.1 > > -- Fernando The speakers of the 5.1 system should just be used, because they are 5 of the same type and because there are equal amps for the speakers. There's no need to keep http://upload.wikimedia.org/wikipedia/de/thumb/4/4e/ITUKreis_Ruhnke.jpg/300px-ITUKreis_Ruhnke.jpg, if the speakers should really be placed correctly for 5.1 at the friends living room at the moment. If possible I would prefer to replace them in a way that's good for ambisonics. From: Arnold Krille To: linux-audio-dev@lists.linuxaudio.org Subject: Re: [LAD] Attenuation of sounds in 3D space Date: Thu, 22 Jul 2010 14:51:00 +0200 [snip] Ambisonics is really every channel with the same priority and use-case. It will not matter whether you use the set up with "front" at positiv-x direction or 130° rotated around the z axis and 30° rotated around the x axis (when using a full 3D rig). It will sound all the same. And the speakers in the room have to be set up for this. Also the speakers are all supposed to be equally away from the listener for best performance [snip] IIUC 4 speakers could be set up in a quadrate with "front" at positiv-x direction and the listener has to be in the middle of the quadrate. Maybe there will be 8 similar speakers and amps, but regarding to the sound card the limit is 8 channels. I guess somewhere on the ambisonics website there will be some text and graphic about such setups. - Ralf ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thursday, July 22, 2010 01:07:57 pm f...@kokkinizita.net did opine: > On Thu, Jul 22, 2010 at 10:35:15AM -0400, Paul Davis wrote: > > On Thu, Jul 22, 2010 at 10:29 AM, Chris Cannam > > > > wrote: > > > Question that just occurred to me. I'm very ignorant about spatial > > > audio, and although I'm sure several of my colleagues could tell me > > > this, I thought it might be sort of on-topic here. Is it possible, > > > or easy, or sensible, or worthwhile, to reduce a B-format recording > > > into stereo in multiple different ways in order to achieve > > > different subjective "listener position" results when using > > > headphones? > > > > my limited understanding is this: the B-format data encodes the > > source position relative to some defined point in space. the decoder > > can map the "origin" used to define the positional space however it > > wants to. whether or not any decoders actually offer any control over > > this is another matter. > > The first order B-format consists of four signals: > > W: equivalent to an 'omni' microphone, > X,Y,Z: equivalent to figure-of-eight microphones > pointing forward/back, left/right, and up/ > down respectively. And interesting scenario, Fons. But it leads this simple minded broadcast engineer with 45 years experience to ask a question. 1. How are the signals brought into phase such that electronically, all mic ribbons or diaphragms seem to occupy the same space, just facing in different directions? If this is not addressed, then this will lead to some interesting comb filter effects if the signals are not kept from mixing, which they will of course do in the ear. Granted, the PV of sound in normal air would require separations of inches till the stuff above high C comes into play, but at the snares and cymbals frequencies, I would have to assume some coloration of the sound from this effect alone. And of course the same concern comes into play at the speakers since they are generally placed around the listener which in no way approximates the nearly single point reception these mics will hear. In my own mind, the placement of a PZ microphone in each of the places one would place the playback speakers would seem to be a superior method, at least for a listener sitting in the nominal center, who will be so overwhelmed by (supposedly not important sonically we are told) the phasing errors that he cannot single out a single largest cause for the lack of realism. In my history of electronic repairs for a living over the last 60+ years, one instance of truly hair raising realism took place when I was about 21, and working one of the service benches at Woodburn Sound in Iowa City IA, USA. I had bought some car parts at noon, and when I left about 6 for dinner, I forgot & left them on the corner of the bench. Having a key to the back door I let myself into the back door about 8, which was pretty dark by then as only one 25 watt bulb out in the display area was on, and half way to the door to my bench area & right in the door to the front, display room, the Dukes of Dixieland marched by, going right over me. It seems that Woody and Saul Marantz were out in front, had pulled a 2nd JBL Hartzfield speaker out of Saul's econoline van, setting it just inside the front door opposite to ours in the other front corner of the display floor, along with a Berlant/Concertone tape deck capable of running at 15 and 30 IPS. And the tape was the master that had cut the Dukes then current hit record, running at 30 ips. SNR was a good 70+ db, and there was no tape hiss audible unless you walked directly in front of the JBL 075 ring radiator tweeters that had been added to both our Hartzfield and to the one Saul was carrying around. No tone controls, and only a 30 watt Marantz stereo amp., those Hartzfields were then, and may be yet, the most efficient speakers ever made, never used more than 3 or 4 watts/channel to get SPL's that would have done Joshua's trumpets at Jericho proud. Truly a total immersion in the sound, from about 35hz to nearly 30khz. Those tweeters could do a fairly good job of reproducing a 25khz square wave. It took till I had been introduced to Saul Marantz and shook hands, and for that tape (on 14" NAB reels) to run out before the hair on the back of my neck was truly relaxed. Saul it turned out was an endless source of technical knowledge sprinkled with BTDT stories. And needless to say, I did not manage to get that hydromatic transmission I had just stick shifted back together till a day later. Yeah, I'm a JOAT. :) -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The cost of living is going up, and the chance of living is going down. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaud
Re: [LAD] Attenuation of sounds in 3D space
On Thu, 2010-07-22 at 14:01 +0200, Ralf Mardorf wrote: > On Thu, 2010-07-22 at 01:04 +0200, Arnold Krille wrote: > > We are not talking about 5.1 or 7.1 here. These suck big time. > > > > We are talking about ambisonics vs. binaurals vs. simple stereo here! > > Ok, I noticed this. > > Fon's AmbDec is the player for the files from > http://www.ambisonia.com/?! > > I guess a friend who lives near to my home has at least 8 outputs for an > Envy24 sound card and at least a JBL 5.1 setup, so the 5.1 speakers > could be used for a minimalist ambisonics. Yes. Fons ships an ambdec configuration for playing in a 5.1 setup (it is not optimal because the back speakers in a 5.1 setup are too far apart but it works - I use it at home). Of course it assumes that the 5.1 setup is correct. This link has a diagram of the speaker angles: http://de.wikipedia.org/wiki/5.1 -- Fernando ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 10:35:15AM -0400, Paul Davis wrote: > On Thu, Jul 22, 2010 at 10:29 AM, Chris Cannam > wrote: > > Question that just occurred to me. I'm very ignorant about spatial > > audio, and although I'm sure several of my colleagues could tell me > > this, I thought it might be sort of on-topic here. Is it possible, or > > easy, or sensible, or worthwhile, to reduce a B-format recording into > > stereo in multiple different ways in order to achieve different > > subjective "listener position" results when using headphones? > > my limited understanding is this: the B-format data encodes the > source position relative to some defined point in space. the decoder > can map the "origin" used to define the positional space however it > wants to. whether or not any decoders actually offer any control over > this is another matter. The first order B-format consists of four signals: W: equivalent to an 'omni' microphone, X,Y,Z: equivalent to figure-of-eight microphones pointing forward/back, left/right, and up/ down respectively. Combining these you can synthesize any type of first order mic, going from omni, over subcardioid, cardioid, hypercardioid to bidirectional, and in any direction. So starting with B-format, you can convert it to stereo using e.g. two figure-of-eights at 90 degrees (Blumlein) or two cardioids at 110 degrees (ORTF), etc. The type of mics and their angle will determine the direct to reverberation ratio to some extent, and therefor the apparent placement of the stereo mic. Such a 'virtual stereo mic' is part of Tetraproc, and there's also a Ladspa plugin doing this. The latter has some problems in Ardour as it has 4 ins and 2 outs, and Ardour get confused by this and will (IIRC) copy inputs 3 and 4 to the outputs while it shouldn't do that. Another way is to decode to a number of speaker signals and then use HRIR (head-related impulse responses) to convert to binaural. Ambdec + Jconvolver (or just Jconvolver with some extra prepartion) can do this. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Floating point processing and high dynamic range audio
Excerpts from lieven moors's message of 2010-07-22 15:20:48 +0200: > On 07/22/2010 05:31 AM, Philipp Überbacher wrote: > > Excerpts from Philipp Überbacher's message of 2010-07-22 03:16:00 +0200: > > > > > Excerpts from fons's message of 2010-07-22 02:24:04 +0200: > > > > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > > > > > > > I think the word loudness is a problem here. Afaik it usually > > refers to > > > > > how it is perceived, and twice the amplitude doesn't mean twice the > > > > > perceived loudness. It may mean twice the sound pressure level, > > energy, > > > > > or intensity (if we ignore analogue anomalies, as you wrote in > > some other > > > > > answer). > > > > > > > > Subjective loudness is a very complex thing, depending on the > > > > spectrum, duration, and other aspects of the sound, and also > > > > on circumstances not related to the sound itself. > > > > > > > > For mid frequencies and a duraion of one second, the average > > > > subjective impression of 'twice as loud' seems to correspond > > > > to an SPL difference of around +10 dB. > > > > > > I had a brief look at the section about loudness in musimathics and it > > > mentions 10 dB based on the work of Stevens, S.S. 1956, > > > "Calculation of the Loudness of Complex Noise" and 6 dB based on > > > Warren, R. M. 1970, > > > "Elimination of Biases in Loudness Judgments for Tones.". > > > I think I've encountered the 6 dB more often in texts, which doesn't > > > mean it's closer to the truth, if that's possible at all. > > > Knowing a 'correct' number would be nice for artists and sound > > > engineers, but if it varies wildly from person to person, as Gareth Loy > > > suggests (no idea where he bases this on) then this simply isn't > > > possible. Picking any number within or around this range is probably as > > > good as any other. > > > > > > > I often wondered what criterion we use to determine which > > > > objective SPL difference sounds as 'twice as loud'. We don't > > > > have any conscious numerical value (there may be unconscious > > > > ones such as the amount of auditory nerve pulses, or the amount > > > > of neural activity), so what it this impression based on ? > > > > > > > > The only thing I could imagine is some link with the subjective > > > > impression of a variable number of identical sources. For example > > > > two people talking could be considered to be 'twice as loud' as > > > > one. But that is not the case, the results don't fit at all (it > > > > would mean 3 dB instead of 10). > > > > > > I never thought about that to be honest. It's immensely complex. It > > > might have to do with each persons hearing capabilities, for example > > the > > > bandwidth of loudness perception or the smallest discernible loudness > > > difference. If it really is very different from person to person, then > > > an explanation that takes the different hearing capabilities into > > > account could be sensible, don't you think? > > > > I did find some more approaches to the problem, but those are just > > ideas. From my personal experience I have to say that I have a very hard > > time saying when something is twice as loud. A musically well trained > > person might have an easier time, I wouldn't know, but for me twice as > > loud is something that is very vague. This might already explain the > > large deviation between subjects as described in musimathics. It lead me > > to another idea though, the evolutionary perspective. Evolutionary it > > likely never was important whether a sound is twice as loud. The only > > situation I can imagine where judging loudness probably was important > > is judging distances. How far is the animal I can't see, be it prey or > > predator, away from me? We know that this takes more than the SPL into > > account, and 'twice as loud' doesn't have relevance in this context. So > > maybe the loudness perception is linked with spatialization. > > I think this is a very interesting idea. Could this be linked to some > kind of > avarage SPL of all the sounds human beings are exposed to (and this variable > changes throughout history). Because when we try to judge the distance of > a barking dog, our brain would use the knowledge of all other dogs we heard > barking before, to estimate the distance of that dog. If we never heard > a dog > before, maybe we would use the sounds of other animals as a reference, > and so on... > > greetings, > > Lieven Hi Lieven, again, I don't know, I can only deduct from experience and reasoning, but I think it could work in a similar way. We can discern lots of different sounds, even sounds that are very similar. For that we need some experience with that particular sound or source, but I think we can learn to recognise sounds very fast. Sounds have multiple properties that allow us to keep them apart, a nice example might be again my lack of experience. In many cases I might not be able to keep a violin and a cello apart. I mig
Re: [LAD] Attenuation of sounds in 3D space
On Thursday 22 July 2010 16:29:01 Chris Cannam wrote: > On Thu, Jul 22, 2010 at 12:48 PM, Paul Davis wrote: > > you don't ned anything fancy to listen to B-format > > recordings, and one of the major reasons for that is fons' open source > > decoder that will allow you to listen to them with any jack-enabled > > audio player and your existing equipment. > > Question that just occurred to me. I'm very ignorant about spatial > audio, and although I'm sure several of my colleagues could tell me > this, I thought it might be sort of on-topic here. Is it possible, or > easy, or sensible, or worthwhile, to reduce a B-format recording into > stereo in multiple different ways in order to achieve different > subjective "listener position" results when using headphones? It makes sense to reduce B-format to stereo. But the target is important, if you aim at headphones, there are decoders that create an binaural signal. If normal stereo-systems are the target, you will do a decoding similar to any ambisonics setup but only use two speakers in the correct stereo positions and decode to file... The headphone-version gives more of the ambisonics feeling, but the normal stereo signal also benefits from the recording done in ambisonics. Have fun, Arnold signature.asc Description: This is a digitally signed message part. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 10:29 AM, Chris Cannam wrote: > Question that just occurred to me. I'm very ignorant about spatial > audio, and although I'm sure several of my colleagues could tell me > this, I thought it might be sort of on-topic here. Is it possible, or > easy, or sensible, or worthwhile, to reduce a B-format recording into > stereo in multiple different ways in order to achieve different > subjective "listener position" results when using headphones? my limited understanding is this: the B-format data encodes the source position relative to some defined point in space. the decoder can map the "origin" used to define the positional space however it wants to. whether or not any decoders actually offer any control over this is another matter. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 12:48 PM, Paul Davis wrote: > you don't ned anything fancy to listen to B-format > recordings, and one of the major reasons for that is fons' open source > decoder that will allow you to listen to them with any jack-enabled > audio player and your existing equipment. Question that just occurred to me. I'm very ignorant about spatial audio, and although I'm sure several of my colleagues could tell me this, I thought it might be sort of on-topic here. Is it possible, or easy, or sensible, or worthwhile, to reduce a B-format recording into stereo in multiple different ways in order to achieve different subjective "listener position" results when using headphones? Chris ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 01:38:22PM +1000, Patrick Shirkey wrote: > A giant Microphone and sound system shall also be erected in his > honour and we shall sing in his name on imporatnt dates like when > sent his first email and farted in melody ;-P Too much. just my birthday will do, it's the first of april. You may think I've been to harsh to R.M., but one has to draw a line somewhere. A few weeks ago two religious fundementalists (don't know which denomination) rang at my gate to discuss the fallacy of Evolution. One of them asked "Did your grandpa look like this ?", showing a picture of an ape. I responded "No, not at all. But let me ask you, did _your_ grandfathers _think_ like apes ?" - "No" - "So why do _you_ ?". And that ended our little discussion. Stating that we have only two ears and that consequently any audio system reproducing 3D would require direct injection into our brains is about at the same level of ignorance. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 08:11:21AM -0400, Paul Davis wrote: > On Wed, Jul 21, 2010 at 11:38 PM, Patrick Shirkey > wrote: > > > Oh yeah, Fons is wonderful and never makes a fool of himself. His shit > > smells sweet too! ;-P > > this was completely pointless. and offensive. and rude. It depends mostly on the type of yesterday evening's pizza I guess. Ciao, -- FA There are three of them, and Alleline. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Floating point processing and high dynamic range audio
On 07/22/2010 05:31 AM, Philipp Überbacher wrote: > Excerpts from Philipp Überbacher's message of 2010-07-22 03:16:00 +0200: > > > Excerpts from fons's message of 2010-07-22 02:24:04 +0200: > > > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > > > > > I think the word loudness is a problem here. Afaik it usually > refers to > > > > how it is perceived, and twice the amplitude doesn't mean twice the > > > > perceived loudness. It may mean twice the sound pressure level, > energy, > > > > or intensity (if we ignore analogue anomalies, as you wrote in > some other > > > > answer). > > > > > > Subjective loudness is a very complex thing, depending on the > > > spectrum, duration, and other aspects of the sound, and also > > > on circumstances not related to the sound itself. > > > > > > For mid frequencies and a duraion of one second, the average > > > subjective impression of 'twice as loud' seems to correspond > > > to an SPL difference of around +10 dB. > > > > I had a brief look at the section about loudness in musimathics and it > > mentions 10 dB based on the work of Stevens, S.S. 1956, > > "Calculation of the Loudness of Complex Noise" and 6 dB based on > > Warren, R. M. 1970, > > "Elimination of Biases in Loudness Judgments for Tones.". > > I think I've encountered the 6 dB more often in texts, which doesn't > > mean it's closer to the truth, if that's possible at all. > > Knowing a 'correct' number would be nice for artists and sound > > engineers, but if it varies wildly from person to person, as Gareth Loy > > suggests (no idea where he bases this on) then this simply isn't > > possible. Picking any number within or around this range is probably as > > good as any other. > > > > > I often wondered what criterion we use to determine which > > > objective SPL difference sounds as 'twice as loud'. We don't > > > have any conscious numerical value (there may be unconscious > > > ones such as the amount of auditory nerve pulses, or the amount > > > of neural activity), so what it this impression based on ? > > > > > > The only thing I could imagine is some link with the subjective > > > impression of a variable number of identical sources. For example > > > two people talking could be considered to be 'twice as loud' as > > > one. But that is not the case, the results don't fit at all (it > > > would mean 3 dB instead of 10). > > > > I never thought about that to be honest. It's immensely complex. It > > might have to do with each persons hearing capabilities, for example > the > > bandwidth of loudness perception or the smallest discernible loudness > > difference. If it really is very different from person to person, then > > an explanation that takes the different hearing capabilities into > > account could be sensible, don't you think? > > I did find some more approaches to the problem, but those are just > ideas. From my personal experience I have to say that I have a very hard > time saying when something is twice as loud. A musically well trained > person might have an easier time, I wouldn't know, but for me twice as > loud is something that is very vague. This might already explain the > large deviation between subjects as described in musimathics. It lead me > to another idea though, the evolutionary perspective. Evolutionary it > likely never was important whether a sound is twice as loud. The only > situation I can imagine where judging loudness probably was important > is judging distances. How far is the animal I can't see, be it prey or > predator, away from me? We know that this takes more than the SPL into > account, and 'twice as loud' doesn't have relevance in this context. So > maybe the loudness perception is linked with spatialization. I think this is a very interesting idea. Could this be linked to some kind of avarage SPL of all the sounds human beings are exposed to (and this variable changes throughout history). Because when we try to judge the distance of a barking dog, our brain would use the knowledge of all other dogs we heard barking before, to estimate the distance of that dog. If we never heard a dog before, maybe we would use the sounds of other animals as a reference, and so on... greetings, Lieven > > My other ideas are rather stupid, just ways to get the right numbers for > your two person idea. > I simply used ln instead of log and got 7, but that's not even Neper and > has no relevance. > > The other idea of that kind is to assume a field quantity, which would > result in 6 dB. I'm still easily confused about 10*log and 20*log, but I > think 20*log is usually used for sound pressure, but maybe not for > psychoacoustic effects. > -- > Regards, > Philipp > > -- > "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und > alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan > > ___ > Linux-audio-dev mailing list > linux-audio-...@... > http://lists.linuxaudio.org/listin
Re: [LAD] Attenuation of sounds in 3D space
Hi, On Thursday 22 July 2010 14:01:36 Ralf Mardorf wrote: > On Thu, 2010-07-22 at 01:04 +0200, Arnold Krille wrote: > > We are not talking about 5.1 or 7.1 here. These suck big time. > > We are talking about ambisonics vs. binaurals vs. simple stereo here! > Ok, I noticed this. > Fon's AmbDec is the player for the files from > http://www.ambisonia.com/?! No. Decoder != Player. Please read the (very fine!) manual to ambdec. And then use any jack-aware player to play the files. I use mplayer and that works great. > I guess a friend who lives near to my home has at least 8 outputs for an > Envy24 sound card and at least a JBL 5.1 setup, so the 5.1 speakers > could be used for a minimalist ambisonics. Keep in mind that 5.1 systems are only a poor substitute for ambisonics set- ups. Even when using jbl-speakers, the set up is still different resulting from the different use cases. 5.1 is practically stereo. Its one mono for the voices (called center), one stereo for music and ambient (called front) and one stereo for special effects (called rear). [Forget about that extra channel for lfe which tries to be smarter then the user.] Ambisonics is really every channel with the same priority and use-case. It will not matter whether you use the set up with "front" at positiv-x direction or 130° rotated around the z axis and 30° rotated around the x axis (when using a full 3D rig). It will sound all the same. And the speakers in the room have to be set up for this. Also the speakers are all supposed to be equally away from the listener for best performance, with 5.1 the rear is supposed to be much nearer to the listeners than the front and center. You see ambisonics and 5.1 are different things. Because of that your (and my) aversion against 5.1 can not be held against ambisonics. And because of that a 5.1 set-up is only of limited use for ambisonics re-production. Have fun, Arnold signature.asc Description: This is a digitally signed message part. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Wed, Jul 21, 2010 at 11:38 PM, Patrick Shirkey wrote: > Oh yeah, Fons is wonderful and never makes a fool of himself. His shit > smells sweet too! ;-P this was completely pointless. and offensive. and rude. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, 2010-07-22 at 01:04 +0200, Arnold Krille wrote: > We are not talking about 5.1 or 7.1 here. These suck big time. > > We are talking about ambisonics vs. binaurals vs. simple stereo here! Ok, I noticed this. Fon's AmbDec is the player for the files from http://www.ambisonia.com/?! I guess a friend who lives near to my home has at least 8 outputs for an Envy24 sound card and at least a JBL 5.1 setup, so the 5.1 speakers could be used for a minimalist ambisonics. > > > A lot of people, even a lot of those who you respect, tried it and I > > never meed someone who preferred mono or stereo to surround. > > I don't understand that last sentence. You argue against using more then two > speaker-channels. And then you tell us you never meet anyone who prefered > mono > or stereo over surround? Bad sentence construction don by me. Cheers! Ralf ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] "El-Cheapo" software-only equivalent
On Thu, Jul 22, 2010 at 6:39 AM, rom wrote: > i'll see if i can create some documentation to make that > "alsa_in/alsa_out" tools less ignored, instead of releasing a new > software. Obviously, with all the proper disclaimers stating that it's > not a substitute for a real multitrack ;-) well, true, but since it all works seamlessly with any JACK-enabled multitrack, it basically isn't a substitute, it just is. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Thu, Jul 22, 2010 at 7:44 AM, Ralf Mardorf wrote: > The picture to the quote „The best listening position is where I sit in > a live performance. With IOSONO you can put the entire audience in my > lap.“ Herbie Hancock, doesn't look like 5.1 or something similar: > http://www.iosono-sound.com/common/files/header/home1_tresor.jpg this is about *audio*. what is looks like tells you almost nothing. in addition, you don't ned anything fancy to listen to B-format recordings, and one of the major reasons for that is fons' open source decoder that will allow you to listen to them with any jack-enabled audio player and your existing equipment. you also don't need any particular speaker setup, although clearly one of the points of ambisonics is that (up to a limit) adding more speakers enables a more accurate recreation of sound placement within 3D to be achieved. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On Wed, 2010-07-21 at 17:45 -0400, Paul Davis wrote: > if that won't work for you, then perhaps you might want to visit any > of the theaters outfitted by these guys: > http://www.iosono-sound.com/references/installations/ The nearest to Oberhausen is http://www.odysseum.de/, unfortunately it's expensive to get from Oberhausen to Köln, but it might be feasible to get there. If the 3D sound system should be good, I fear that still the kind of production isn't something that will be able to demonstrate it, http://www.odysseum.de/id-3d-filme.html?! Reputable would be the Hochschule für Musik Detmold, but it's to far away for my purse and perhaps it won't be easy for a guest to be allowed to listen to a performance, because it's a school. The picture to the quote „The best listening position is where I sit in a live performance. With IOSONO you can put the entire audience in my lap.“ Herbie Hancock, doesn't look like 5.1 or something similar: http://www.iosono-sound.com/common/files/header/home1_tresor.jpg System requirements Operating System: Windows XP Professional SP2, Windows 7 Host application: Steinberg`s Nuendo 4 (Nuendo dongle required) Processor: Dual Core 2.4 Ghz Graphic board: Open-GL support recommended Sound card: 6 Output Channels or more recommended Display: Resolution 1280 x 1024 Px, Dual Display recommended I'm interested to listen to a performance. Cheers! Ralf ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] "El-Cheapo" software-only equivalent
Hi, last night i finally managed to try jackd+alsa_in and yes, it works! I used an intermittent beep as a test signal. One thing i've noticed, is that the master stream is about 450-500 frames early in respect to the slave streams, while the gap among the 3 slave streams is within 35-40 frames. I'll try to tune things up a bit, and see if it get better. > theoretically your tool could achieve better sound quality than alsa_in, > because it doesnt need to be realtime. (it could also do perfect phase > alignment) > ...hmm, it would require some serious math skills that i don't have :-( And moreover, i don't think it would make much sense to seek for sound quality in this context. It is enough to be able to get something barely decent, using only some junk computer parts that were laying around in your attic (...the first version was able to record 4 channels on a Pentium 166 with 24MB of ram :-D ) > so the basic question is, if you are still motivated to continue working > on it yeah, actually, i had already stopped working on the core functionality of my program because it was just good enough for my purpose. Now that i know of the existence of alsa_in, i don't think i'm going to release a new project to confuse people even more. Instead, now i was wondering if it could be useful to move the alsa_in functionality to a lower level, like an alsa plugin. But from what you said, i guess the alsa_in algorithm prefers the "always-on" behaviour of jack (it starts capturing immediately as you start the daemon), instead of the start-stop behaviour of a typical pure-alsa recording application. So, i think the answer is no, and alsa_in is simply the perfect tool i've never heard of before! Aaargh :-D (...well, i started putting together my program in dec-2008, so maybe it just wasn't there at the time...) thanks very much to all of you. i'll see if i can create some documentation to make that "alsa_in/alsa_out" tools less ignored, instead of releasing a new software. Obviously, with all the proper disclaimers stating that it's not a substitute for a real multitrack ;-) bye alberto ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Floating point processing and high dynamic range audio
Excerpts from Philipp Überbacher's message of 2010-07-22 03:16:00 +0200: > Excerpts from fons's message of 2010-07-22 02:24:04 +0200: > > On Thu, Jul 22, 2010 at 01:05:01AM +0200, Philipp Überbacher wrote: > > > > > I think the word loudness is a problem here. Afaik it usually refers to > > > how it is perceived, and twice the amplitude doesn't mean twice the > > > perceived loudness. It may mean twice the sound pressure level, energy, > > > or intensity (if we ignore analogue anomalies, as you wrote in some other > > > answer). > > > > Subjective loudness is a very complex thing, depending on the > > spectrum, duration, and other aspects of the sound, and also > > on circumstances not related to the sound itself. > > > > For mid frequencies and a duraion of one second, the average > > subjective impression of 'twice as loud' seems to correspond > > to an SPL difference of around +10 dB. > > I had a brief look at the section about loudness in musimathics and it > mentions 10 dB based on the work of Stevens, S.S. 1956, > "Calculation of the Loudness of Complex Noise" and 6 dB based on > Warren, R. M. 1970, > "Elimination of Biases in Loudness Judgments for Tones.". > I think I've encountered the 6 dB more often in texts, which doesn't > mean it's closer to the truth, if that's possible at all. > Knowing a 'correct' number would be nice for artists and sound > engineers, but if it varies wildly from person to person, as Gareth Loy > suggests (no idea where he bases this on) then this simply isn't > possible. Picking any number within or around this range is probably as > good as any other. > > > I often wondered what criterion we use to determine which > > objective SPL difference sounds as 'twice as loud'. We don't > > have any conscious numerical value (there may be unconscious > > ones such as the amount of auditory nerve pulses, or the amount > > of neural activity), so what it this impression based on ? > > > > The only thing I could imagine is some link with the subjective > > impression of a variable number of identical sources. For example > > two people talking could be considered to be 'twice as loud' as > > one. But that is not the case, the results don't fit at all (it > > would mean 3 dB instead of 10). > > I never thought about that to be honest. It's immensely complex. It > might have to do with each persons hearing capabilities, for example the > bandwidth of loudness perception or the smallest discernible loudness > difference. If it really is very different from person to person, then > an explanation that takes the different hearing capabilities into > account could be sensible, don't you think? I did find some more approaches to the problem, but those are just ideas. From my personal experience I have to say that I have a very hard time saying when something is twice as loud. A musically well trained person might have an easier time, I wouldn't know, but for me twice as loud is something that is very vague. This might already explain the large deviation between subjects as described in musimathics. It lead me to another idea though, the evolutionary perspective. Evolutionary it likely never was important whether a sound is twice as loud. The only situation I can imagine where judging loudness probably was important is judging distances. How far is the animal I can't see, be it prey or predator, away from me? We know that this takes more than the SPL into account, and 'twice as loud' doesn't have relevance in this context. So maybe the loudness perception is linked with spatialization. My other ideas are rather stupid, just ways to get the right numbers for your two person idea. I simply used ln instead of log and got 7, but that's not even Neper and has no relevance. The other idea of that kind is to assume a field quantity, which would result in 6 dB. I'm still easily confused about 10*log and 20*log, but I think 20*log is usually used for sound pressure, but maybe not for psychoacoustic effects. -- Regards, Philipp -- "Wir stehen selbst enttäuscht und sehn betroffen / Den Vorhang zu und alle Fragen offen." Bertolt Brecht, Der gute Mensch von Sezuan ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On 2010.07.22. 1:30, f...@kokkinizita.net wrote: On Wed, Jul 21, 2010 at 10:07:10PM +0200, JohnLM wrote: What's the thing about far and near fields? The rule pressure = 1 / distance is true only for theoretical point sources, and for real sources if the distance is much larger than the size of the zource. In the other case you are in the 'near field' where things can get quite complex. For some sounds you are almost always in the 'near' field e.g. a highway with many moving cars on it, the seashore, etc. These are essentially large line sources with many independent sound generators which blurr into a single sound, and in that case you'd get different relations, e.g. pressure = 1 / sqrt(distance). On Wed, Jul 21, 2010 at 2:01 PM, wrote: An audio signal represents pressure variation as a function of time. Multiplying it by two will give 2 times the pressure, and 4 times the power. The subjective result is another matter. Ummm... is it sound pressure or sound pressure level? Or it doesn't matter? (are they equivalent?) The term 'sound pressure level' (SPL) usually refers to sound pressure measured in a standardized way. What you try to do is called spatialization. It involves modelling the directivity and motion of the sources and their interaction with the space they are in, and it can get arbitrarily complex. Software to do this in specialised cases (e.g. electronic music) exists. More general solutions and in particular practical systems (allowing complex and dynamic scenes) are still a research topic, e.g. at Barcelone Media. Ciao, I may have bitten more than I can chew on. :) Currently I seek to make "stupid" solution. Something like the way every decent game engine does it. Except my solution is going to be non-realtime and not (sound) hardware dependent. I reckon something like this already exist in FOSS, but I haven't been able to find anything (I have no time examining code of every other audio project out there). Thanks for the info. Good to know I'm heading the right way. Indeed 'near field' sound sources were ones I never actually gave much thought on their implementation in software. This will go next on my TODO list. Regards, John ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] STEREO RULES
Ralf Mardorf wrote: People today aren't able to do a good stereo or mono mix, e.g. because of the loudness war, but they are thinking of doing 3D mixes. I'm unable to follow this strange evolution. I did have a bit of mistrust in 3D (although with less extreme feelings than yours), and especially based on cheezy and naive use in many films... That was till we did an ambisonics recording and playback experiment, also comparing other 2-dimensional recording configurations. You should really try it! Also 3D meaning more than 2 channels positioned in space has lots of creative potential (i.e. not using it to reproduce a recorded sonic space, but creating it from zero) Lorenzo. We all have 2 ears and 1 brain that has to do a lot of work, regarding to information from the sense organs. The brain needs to do math because usually the left and right ear are not equal, so even when wearing a head phone the brain needs the context of the situation and the perfect natural loudness etc. for this context. All thoughts about doing 3D are useless until we aren't able to connect electrodes directly to our brains and to have a rimming regarding to our brains. As long as Cochlear implant isn't good, any try to do 3D mixing is laughable, resp. a pain, just try to watch AND hear a modern film, it's a torture. There are some good mixes for stereo and mono, but at least I never heard a valid mix with more but one ore two channels. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
Re: [LAD] Attenuation of sounds in 3D space
On 21 July 2010 22:18, Ralf Mardorf wrote: > Btw. sometimes I do fail too, so I don't insist that I'm not mistaken, > to the contrary, it would be a win for me too, if I should fail with my > opinion. Basically, just as long as you post twenty thousand emails to every goddamn linux audio related mailing list per hour you're happy. ___ Linux-audio-dev mailing list Linux-audio-dev@lists.linuxaudio.org http://lists.linuxaudio.org/listinfo/linux-audio-dev
