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Re: the number of fixed categories in absolute pitch

Dear Leon, and others,

on Thursday, April 29, Leon van Noorden wrote:

> The difference between AP and NAP subjects has been explained by the
> assumption that in tasks of absolute pitch identification NAP subjects can
> 'transmit' about 3 bits on a single frequency dimention, while AP subjects
> can transmit about 3 bits on each of two dimensions: Pitch height and
> Chroma.(the magical number of 7 plus or minus 2, times two).

I cannot see that this "explanation" would seem realistic. What we observe
is that concerning the "pitch height (timbre) dimension" there is no
apparent difference between APers and non-APers. [So they would have the
same "bit capacity" here ;-)]

Also, concerning the number of chroma categories there is no difference
between APers and non-APers. The difference simply is that APers have fixed
ones and non-APers have movable ones.

> I would like to scrutinize the experimental setup of the
> experiment where the subjects showed the ability of indicating "C plus ca
> cents". It should have been made sure that the subject was not able to use
> relative pitch as a third dimension.

Why should they refer to relative pitch here? These people instantaneously
und simultaneously hear that a tone is close to "C" AND "ca 0.1 semitone
above it". I am not aware of experimental studies on this ability, but I
assume that most members of this list must have heard anecdotal evidence
about it. Most APers have it to some extent. But the accuracy, that is the
resolution in Cent, varies greatly between them.


Martin Braun
Neuroscience of Music
S-671 95 Klässbol
web site: http://w1.570.telia.com/~u57011259/index.htm