Subject: Re: AUDITORY Digest - 4 Jul 2008 to 5 Jul 2008 (#2008-137) From: Kent Walker <kent.walker@xxxxxxxx> Date: Sun, 6 Jul 2008 09:40:10 -0400 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>HI Junyong, Atsushi Marui and Bill Martens have done research on perceived quality of distortion effects. http://www.music.mcgill.ca/~marui/index.php?List%20of%20Publications Perceived quality of a system usually changes with loudness. We tend to prefer louder stimuli (until it causes discomfort), which is why tests of sound quality usually match loudness as a first step. Kent Walker PhD Candidate Sound Recording Area Schulich School of Music McGill University 555 Sherbrooke Street West Montreal, Quebec Canada H3A 1E3 Home Phone: +1 (514) 485-6568 Office Phone: +1 (514) 398-4535 ext 094962 Mobile: +1 (514) 222-3283 Fax: +1 (514) 398-8061 www.music.mcgill.ca/~kentw On 7/6/08 12:00 AM, "AUDITORY automatic digest system" <LISTSERV@xxxxxxxx> wrote: > There is 1 message totalling 59 lines in this issue. > > Topics of the day: > > 1. A problem about the relationship between perceived quality and loudness! > thanks > > ---------------------------------------------------------------------- > > Date: Fri, 4 Jul 2008 08:20:53 -0400 > From: Bob Masta <audio@xxxxxxxx> > Subject: Re: A problem about the relationship between perceived quality and > loudness! thanks > > Perhaps not exactly what you asked about, but many years > ago (1970s?) there was a study where subjects were asked to > adjust the volume of various audio systems until they were > "loud". The surprising result was that high-powered > systems were turned up to much higher output levels than > low-powered systems before they were "loud". The > explanation given was that subjects apparently correlated > increased distortion (more than actual SPL) with "loud". > > Since amp distortion shoots up as the amp begins to clip at > its maximum output level, the low-powered amps of course > began to distort while producing lower SPL than the high- > powered amps. > > > Best regards, > > Bob Masta > > > ----------------------------------- > On 3 Jul 2008 at 18:20, Junyong You wrote: > >> Hi All, >> >> As we know, loudness is an important audio index for human perception. Is >> there anyone studied the relationship between quality distortion and the >> loudness? I mean, if the same objective distortion happened on the different >> audios (or segments) with different loudness, then, is there some difference >> between the perceived qualities of these two audios (or segments)? >> >> I guess the loudness should influence the perceived quality of same >> distortion, and for the very low and very high loudness, such influence >> maybe not very great, but with ordinary loudness, perhaps the perceived >> distortion will increase following the loudness. >> >> This is just my guess, anybody can help to work for it with me? Or could you >> please give me some advice and references? >> >> Thank you very much, any feedback will be greatly appreciated. >> >> Best Regards, >> >> Junyong > > Bob Masta > > D A Q A R T A > Data AcQuisition And Real-Time Analysis > www.daqarta.com > Scope, Spectrum, Spectrogram, Signal Generator > Science with your sound card! > > ------------------------------ > > End of AUDITORY Digest - 4 Jul 2008 to 5 Jul 2008 (#2008-137) > *************************************************************