Hi Didier, I count myself as having good hearing, I always wear ear protection at any gigs / loud events and have always done so. My hearing is very important to me since it is essential for my livelihood.
I made a new test, a 440 hz sine wave with three 0.25 second white noise bursts -66 dB, -72 dB and -75 dB below the sine (which is at -6 dBFS). I can hear the first one very clearly, then just hear the second one. I can't actually hear the hiss of the third one but I can hear the amplitude of the sine wave fractionally lowering when the actual amplitude of the test sine remains constant, I don't know why this is but that's how I hear it. You will clearly see where the white noise bursts are if you use some sort of FFT display, but please just have a listen first and try and pick where each (3 total) are in the file: www.cytomic.com/files/dsp/border-of-hearing.wav For the other way around, a constant noise file and with bursts of 440 hz sine waves, the sine has to be very loud before I can hear it, up around -28 dB from memory. Noise added to a sine wave is much easier to pick, which is why I think low pass filtered tones that are largely sine like in nature are the border case for dither. All the best, Andy -- cytomic -- sound music software -- On 10 February 2015 at 10:56, Didier Dambrin <di...@skynet.be> wrote: > I'm having a hard time finding anyone who could hear past the -72dB noise, > here around. > > Really, either you have super-ears, or the cause is (technically) somewhere > else. But it matters, because the whole point of dithering to 16bit depends > on how common that ability is. > > > > > -----Message d'origine----- From: Andrew Simper > Sent: Saturday, February 07, 2015 2:08 PM > > To: A discussion list for music-related DSP > Subject: Re: [music-dsp] Dither video and articles > > On 7 February 2015 at 03:52, Didier Dambrin <di...@skynet.be> wrote: >> >> It was just several times the same fading in/out noise at different >> levels, >> just to see if you hear quieter things than I do, I thought you'd have >> guessed that. >> >> https://drive.google.com/file/d/0B6Cr7wjQ2EPub2I1aGExVmJCNzA/view?usp=sharing >> (0dB, -36dB, -54dB, -66dB, -72dB, -78dB) >> >> Here if I make the starting noise annoying, then I hear the first 4 parts, >> until 18:00. Thus, if 0dB is my threshold of annoyance, I can't hear >> -72dB. >> >> So you hear it at -78dB? Would be interesting to know how many can, and if >> it's subjective or a matter of testing environment (the variable already >> being the 0dB "annoyance" starting point) > > > Yep, I could hear all of them, and the time I couldn't hear the hiss > any more as at the 28.7 second mark, just before the end of the file. > For reference this noise blast sounded much louder than the bass tone > that Nigel posted when both were normalised, I had my headphones amp > at -18 dB so the first noise peak was loud but not uncomfortable. > > I thought it was an odd test since the test file just stopped before I > couldn't hear the LFO amplitude modulation cycles, so I wasn't sure > what you were trying to prove! > > All the best, > > Andy > > > > >> -----Message d'origine----- From: Andrew Simper >> Sent: Friday, February 06, 2015 3:21 PM >> To: A discussion list for music-related DSP >> Subject: Re: [music-dsp] Dither video and articles >> >> Sorry, you said until, which is even more confusing. There are >> multiple points when I hear the noise until since it sounds like the >> noise is modulated in amplitude by a sine like LFO for the entire >> file, so the volume of the noise ramps up and down in a cyclic manner. >> The last ramping I hear fades out at around the 28.7 second mark when >> it is hard to tell if it just ramps out at that point or is just on >> the verge of ramping up again and then the file ends at 28.93 seconds. >> I have not tried to measure the LFO wavelength or any other such >> things, this is just going on listening alone. >> >> All the best, >> >> Andrew Simper >> >> >> >> On 6 February 2015 at 22:01, Andrew Simper <a...@cytomic.com> wrote: >>> >>> >>> On 6 February 2015 at 17:32, Didier Dambrin <di...@skynet.be> wrote: >>>> >>>> >>>> Just out of curiosity, until which point do you hear the noise in this >>>> little test (a 32bit float wav), starting from a bearable first part? >>>> >>>> >>>> >>>> https://drive.google.com/file/d/0B6Cr7wjQ2EPucjFCSUhGNkVRaUE/view?usp=sharing >>> >>> >>> >>> I hear noise immediately in that recording, it's hard to tell exactly >>> the time I can first hear it since there is some latency from when I >>> press play to when the sound starts, but as far as I can tell it is >>> straight away. Why do you ask such silly questions? >>> >>> All the best, >>> >>> Andrew Simper >> >> >> -- >> dupswapdrop -- the music-dsp mailing list and website: >> subscription info, FAQ, source code archive, list archive, book reviews, >> dsp >> links >> http://music.columbia.edu/cmc/music-dsp >> http://music.columbia.edu/mailman/listinfo/music-dsp >> >> >> ----- >> Aucun virus trouve dans ce message. >> Analyse effectuee par AVG - www.avg.fr >> Version: 2015.0.5645 / Base de donnees virale: 4281/9068 - Date: >> 06/02/2015 >> -- >> dupswapdrop -- the music-dsp mailing list and website: >> subscription info, FAQ, source code archive, list archive, book reviews, >> dsp >> links >> http://music.columbia.edu/cmc/music-dsp >> http://music.columbia.edu/mailman/listinfo/music-dsp > > -- > dupswapdrop -- the music-dsp mailing list and website: > subscription info, FAQ, source code archive, list archive, book reviews, dsp > links > http://music.columbia.edu/cmc/music-dsp > http://music.columbia.edu/mailman/listinfo/music-dsp > > > ----- > Aucun virus trouve dans ce message. > Analyse effectuee par AVG - www.avg.fr > Version: 2015.0.5645 / Base de donnees virale: 4281/9071 - Date: 07/02/2015 > -- > dupswapdrop -- the music-dsp mailing list and website: > subscription info, FAQ, source code archive, list archive, book reviews, dsp > links > http://music.columbia.edu/cmc/music-dsp > http://music.columbia.edu/mailman/listinfo/music-dsp -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
