Re: AUDITORY Digest - 23 May 1999 to 27 May 1999 (#1999-74)

["Sandra E. Trehub" <sandra.trehub@xxxxxxxxxxx>]

Robert:
Shepard (JASA, 1964 36, 2346-2353) reported that, of 50 unselected
(seemingly normal) colleagues and assistants at Bell Telephone
Laboratories, only 62% could consistently report whether the second of two
sinusoidal tones was higher or lower than the first, even when the tones
differed by a little more than a semitone (1/10 of an octave). Several
listeners performed at chance levels, but those who were interested in
music (whether or not they played a musical instrument) were near perfect.
Perhaps this is the "well established" finding in question.

Another study may be relevant, this one by Zatorre (JASA 1988, 84,566-572.
In that study, as you may recall, individuals heard a pair of tones (with
the fundamental present or absent) and had to judge whether the pitch rose
or fell. The pitch differences (200/300 Hz, 400/600 Hz, 600/900 Hz) were
greater than those in Shepard's study; was that because individuals had
more difficulty identifying pitch direction with smaller pitch differences?
Sandra

>Date:    Thu, 27 May 1999 16:24:24 -0400
>From:    "Robert J. Zatorre" <MD37@MUSICA.MCGILL.CA>
>Subject: pitch discrimination
>
>Dear List
>
>A reviewer of a recent paper of ours has written the following:
>
>"...I thought it was well established that 10 to 30% of normal subjects
>cannot judge which frequency [in a pair of pure tones] is higher or lower
>(above chance), while all subjects are generally able to judge if two
>frequencies are identical or not."
>
>My question: is this, in fact, well established, as the reviewer claims,
>and if so, what might be the reference for this?
>
>Any leads you all can give us would be appreciated
>
>Thanks
>
>Robert
>Robert J. Zatorre, Ph.D.

______________________________________
Sandra E. Trehub
Department of Psychology
University of Toronto at Mississauga
Mississauga, Ontario, CANADA L5L 1C6
TEL (905)828-5415  FAX (905)569-4326
***Note new e-mail address: sandra.trehub@utoronto.ca