Re: AUDITORY Digest - 4 Jul 2008 to 5 Jul 2008 (#2008-137)

[Kent Walker <kent.walker@xxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxx>
> 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)
> *************************************************************