Apple's audio APIs do support HRTF on OSX: http://developer.apple.com/audio/overview.html
but apparently HRTF has not made it to the iPhone: http://www.steamboatmountaindesigns.com/blog/2009/02/openal-for-iphone-does-not-support-hrtf.html Would be nice if these guys ported the Mac fmod sound system to iPhone: http://www.garagegames.com/community/blogs/view/16489 CB Chris Hofstader wrote: > The most "accurate" spatial audio information uses a technique called > Head Relative Transform Functions (HRTF) which simulates relatively > precise tonal qualities of sounds that one perceives from a specific > direction. > > Some of the research into what became these functions had humans > sitting with dozens of very tiny microphones set up in an array in > their ears. there was more than enough similarity for the physicists > to resolve the raw data into a number of mathematical equations and > the output of said functions is amazing. > > the problem with HRTF is that it is very compute intensive. Of > course, when I first started diddling about with it, I was on what is > now a six year old Dell desktop. A dual core, 64 bit laptop should be > able to handle these equations in real time much more easily. > > Microsoft has for a number of years now included HRtF in DirectSound > (the audio component of Drect X) and my experiments with them showed > very promising results. I don't know the Macintosh API too well so I > don't know if they have something similar, identical or not. The > Microsoft documentation does warn about relying too much on these > functions as they can bog down the processor and cause other threads > to behave kind of badly (again, all of the faster new computers should > be able to calculate these sounds in real time. > > I've loads of ideas for a combination of really accurate sound > combined with a haptic interface using the Falcon to simulate a whole > lot of 3 dimensional real world objects. > > cdh > > > > > On Jul 30, 2009, at 5:06 PM, Chris Blouch wrote: > >> I've heard there is a lot more to spacial placement than just >> fiddling with the pan to adjust volume levels. At least this seems >> obvious to me when a little pan to the left makes the sound fly way >> off to the left of the sound field. Probably a lot more going on in >> the ear that isn't fooled by that trick. So, that said, do you have >> any idea if the VoiceOver positional audio is doing real sound field >> magic or is it just a subtle pan? >> >> One underrated feature on the new iPhone is the compass. With this an >> application can not only know where you are but also which way you >> (or at least your phone) is pointed. This makes possible real walking >> directions from where you're at using left and right rather than >> assuming the user has their cardinal orientation correct. Even >> feedback to say what is in front of you in the direction you are >> pointing. Should be good things coming. >> >> CB >> >> Chris Hofstader wrote: >>> Including the two textbook chapters (one entirely on games and another >>> with a portion on audio games), a couple of peer reviewed articles on >>> the matter, a pile of blog articles >>> (http://www.blindconfidential.blogspot.com >>> ) and the odd item here and there, I have studied a handful of audio >>> games in depth, fooled around with a few others and talked to a lot of >>> their authors but the breadth of my knowledge is far more narrow than >>> a dozen hardcore gamers I know and rely on for brief descriptions for >>> new entries so I can quickly ascertain how they may move the science >>> in a new and/or different and interesting direction. >>> >>> As I said this morning, I am far too boring to actually build a real >>> game and, when you scratch beyond the surface, you will find that >>> first and for mostly, I think about putting technology in the hands of >>> blinks that will provide them with the tools they may choose to employ >>> in a job or school situation. >>> >>> >>> If you are interested in mixing sound and tactile feedback, get a look >>> at a Falcon 3D tactile controller. I think they have an SDK for Mac >>> and they do .5 mm tactile resolution (most humans can feel no better >>> than .1 mm) so you can do extraordinary things with this device and >>> they only cost about $ 100 (really). >>> >>> I like the idea of using the iPhone for orientation and to provide >>> information about one's surroundings. I'm not especially impressed by >>> the iPhone's Maps application but its location services are pretty >>> excellent. I thought of this while walking through Harvard Yard after >>> lunch today and wondered how a student new to the university would >>> find the library as opposed to the historical center next door as none >>> of these buildings have traditional street addresses and are arrived >>> at by foot paths. Your idea could give a student a lot of good >>> information and can be used as a fallback if they get confused. >>> >>> Cool idea. >>> cdh >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> On Jul 30, 2009, at 12:29 PM, Mark Baxter wrote: >>> >>> >>>> I really wonder why no one's heard of AudioQuake with MindGrid. The >>>> project has somewhat stalled out over the past two years, but the >>>> "Jedi Quake," version, written by Cara Quinn and others, is the best >>>> 3D audio simulation I've seen. I can't speak for the parallel- >>>> processing audio capacity of the brain, but immediately this game and >>>> its maps made me start thinking about "mobility orientation," >>>> applications. Having only ever encountered a mobility orienting >>>> instructor for the first time in memory last year, I don't know much >>>> about how most blind people do it, but I'm sure my skills aren't that >>>> different from the norm, and I saw implications for map-making and >>>> environment-learning, which is where I wanted to go with apps for the >>>> Iphone. I still have a Windows laptop running XP; I'll check out >>>> shades of doom. >>>> >>>> >>>> Mark BurningHawk >>>> >>>> Skype and Twitter: BurningHawk1969 >>>> MSN: burninghawk1...@hotmail.com >>>> My home page: >>>> http://MarkBurningHawk.net/ >>>> >>>> >>>> >>> >>> >>> >>> >> >> >> > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "MacVisionaries" group. 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