If you appreciably alter the music during playback you might technically run afoul of performance rights and licensing law
On Mon, Jan 10, 2022, 1:38 PM vicki melchior <[email protected]> wrote: > Okay. In the context of subtractive dither, I understand the confusion. > Yes, the purpose of subtractive dither is to reduce the total dither noise > remaining in the output, typically after adding dither during bit > reduction. Clearly, that will increase the SNR and allow you to hear more > of the signal. > > > > On Jan 10, 2022, at 12:58 PM, Zhiguang Zhang <[email protected]> wrote: > > sampo started this thread as OP so not sure what this discussion is about, > i think he was talking about 'subtractive' dither. i actually think the > problem is more nuanced, perhaps a music business problem dealing with > music publishing and licensing law > > On Mon, Jan 10, 2022 at 12:55 PM vicki melchior <[email protected]> > wrote: > >> Eric, >> >> You’ve lost me. I don’t follow what you are worrying about. This >> discussion isn’t about the audibility of dither. In fact white noise >> generally is fairly benign from an audibility standpoint. >> >> The reasons dither is added have to do with avoidance of distortion due >> to undithered quantization error, It is this distortion that can be quite >> audible and can produce coloration, because the distortion is coherent in >> nature and not noiselike. >> >> Vicki >> >> On Jan 10, 2022, at 12:33 PM, Zhiguang Zhang <[email protected]> wrote: >> >> well i'm not here to talk about whether or not i can discriminate dither >> from music, it is pointless for me as someone who listens to music >> >> On Mon, Jan 10, 2022 at 12:31 PM vicki melchior <[email protected]> >> wrote: >> >>> No, I never said that dither becomes a coherent signal. Dither is >>> noise. >>> >>> >>> On Jan 10, 2022, at 12:14 PM, Zhiguang Zhang <[email protected]> >>> wrote: >>> >>> Vicki, >>> >>> that is rather incredible to me if true, that dither is detectable as a >>> coherent signal but i suppose that the dither that i was referring to is >>> *necessarily* a part of the program material signal because it is the >>> dither that has already been added during the recording chain and thus not >>> a separate coherent signal >>> >>> https://ask.audio/articles/the-how-and-why-of-dithering-in-pro-tools >>> >>> On Mon, Jan 10, 2022 at 9:15 AM vicki melchior <[email protected]> >>> wrote: >>> >>>> Eric, I’m not sure I get the gist of your question, but “hearing into >>>> the noise” refers to the fact that coherent signals can be detected at some >>>> level (around 10-15 dB) below the RMS level of the noise (whether the noise >>>> is dither or part of the signal). The mathematical analogy for this is >>>> coherent/noncoherent gain; the hearing system integrates both noise and >>>> signal over the bandwidth of the particular cochlear filter. Noise >>>> integrates non-coherently while signal integrates coherently, leaving a net >>>> gain in SNR. This is relevant for a number of reasons. First, you can >>>> (maybe) detect actual signal at those depths below noise. But second, you >>>> can also hear distortion lying well below the noise floor if it is >>>> relatively coherent, especially the peaks associated with truncation >>>> distortion when dither has been omitted. These arguments are highly >>>> relevant to determining the bit depth needed to convey program material, >>>> and that in turn, is a function of the dynamic range audible to humans >>>> along with an understanding of the noise sources present in the given >>>> system. So it is not about hearing the noise, but rather hearing signal >>>> below the noise floor. >>>> >>>> >>>> On Jan 9, 2022, at 8:10 PM, Zhiguang Zhang <[email protected]> wrote: >>>> >>>> not sure if this point is important, but the dither that is added >>>> before you hear the program material being reproduced isn't actually >>>> supposed to be 'heard' - so this argument doesn't appear to make much sense >>>> in my mind. engineers might hear the dither when they're familiar with the >>>> studio that they work in, but past that, i'm not sure i get the point of >>>> discussing the practical limits of hearing something added which, for all >>>> intents and purposes, is hidden. it's almost like you're trying to reverse >>>> engineer what recording interface an audio engineer was using >>>> >>>> On Sun, Jan 9, 2022 at 5:48 PM Brian Willoughby < >>>> [email protected]> wrote: >>>> >>>>> Thank you for these titles. I've already found them in the AES library. >>>>> >>>>> Brian Willoughby >>>>> >>>>> >>>>> On Jan 9, 2022, at 13:43, vicki melchior <[email protected]> >>>>> wrote: >>>>> > As far as measurements of how far “into the noise” we can hear, >>>>> there aren’t a lot of good published numbers that I know of (having >>>>> reviewed the subject a couple of years ago), but Bob Stuart and Peter >>>>> Craven argue dynamic range and, to a certain extent, audibility below the >>>>> noise floor in a couple of papers published in JAES in 2019. They are >>>>> based on psychoacoustic arguments as well as listening test results, the >>>>> latter as part of their studio and lab work on MQA. If interested, their >>>>> (open access) papers are in the AES e-lib, “The Gentle Art of Dithering” >>>>> and “A Hierarchical Approach for Audio Capture, Archive and Distribution”. >>>>> >>>> >>>> >>> >> >
