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Re: Perception as memory

Dear Pierre,

I had nearly the same reaction as you, but I suppressed it.
But now you are talking about it I have to disclose the reasons why I hesitated.

Although AP reveals the 'chroma side' of pitch it has a lot to do with the spectral or 'vowelness side' of pitch. (or tone height).

It is not uncommon to hear from AP subjects that the words of lyrics interfere with the label of the tones when they have to learn to sing a unknown melody from a score. They have to learn first the melody using their own tone labels and then learn the lyrics on that melody.

Long ago I have also performed some reaction time studies on note identification. With me as the only subject. Under pressure I made quite a lot confusion errors between fa and la and between si and mi.

So I think that AP subjects use a connection between the chroma and the tone height dimensions of pitch.

This is also in line with the conclusion of a researcher in the time of information theory, who calculated that in the identification of tones AP's transmitted a number of bits per symbol corresponding to two dimensions and non-AP's corresponding to only one dimension. I have this only in a manuscript that is somewhere in the stacks I collected during my post-doc at Bell Labs. 1975-1976

Now I think about it I can imagine the reason why subjects 'born with a tone language' develop, according to Diana, much more often AP: as the pitch contour of a word is used to modify the meaning most often transmitted by the 'vowelness side' of pitch they have to establish a stronger link between chroma and tone height.

Does this makes sense?



On 31 Aug 2009, at 17:49, Pierre Divenyi wrote:

Dear Eric, Diana, Leon, and other AP fans,

I have one problem with a basilar membrane interpretation of the AP shift: we are talking about chroma, not place and, because the thickness of the membrane is not uniform, it is har to believe that an age-related thickening would have the same effect (on a roughly logarithmic scale) over the whole length. This is why I am more in favor of assigning the (upward) shift to a
central phenomenon, consistent with a slowing of the internal clock.
Naturally, that would explain neither a downward shift nor a diurnal change. However, I am not sure how to interpret any diurnal change since, ever since Brady's experiment on learning AP "in 365 trials, one per day, in order to eliminate any relational judgment", and as a result of my own experience making me able to remember (and unable to rid myself of) a certain tonality over several hours, I have a great respect for relative pitch. So, if there is long-term memory for relative pitch, it will have to be considered a
factor in any diurnal AP change.


On 8/31/09 8:12 AM, "Eric LePage" <ericlepage@xxxxxxxxxxxxxxx> wrote:

In reply to your message dated 29/08/2009 at 16:18

Dear Diana, and list,

Thanks for your personal comments.  You noted:

Philip Vernon wrote an entertaining article about his shift of AP with
age in the British Journal of Psychology 1977, 68, 485-489.

I found the article in my reprint collection, but inside I found a letter
from Philip Vernon which accompanied the reprint, dated September
19, 1978.  He would then have been aged 72.  Rereading the article
he specifically suggested how his experience is consistent with a
change in stiffness of the basilar membrane.

One of his comments to me echoes your own comments about

"My own hearing is, I would say, quite normal, apart from some
natural tendency to deafness with age.  But the deviance of my
pitch norms is quite liable to fluctuate. E.g., at an ordinary orchestral or chamber concert, I may start off identifying the keys a semitone too high, and then notice half-an-hour later that everything is a tone too
high;  sometimes, of course, I am uncertain of which is predominant.
But I don't seem to find any fluctuations with health, colds, or other
conditions.    (Signed: Philip E Vernon)"

So he seems to be suggesting that the same underlying parameter
varies in the short-term as well as with age. Perhaps the same
parameter explains the variation of AP with menses (Wynn, 1971) ?
Andrew Bell (HR1992) also showed that spontaneous OAE
frequencies also shift with menses, again suggesting a link
with cochlear mechanical stiffness.  Recently I showed a post-hoc
analysis of CEOAEs suggesting a possible diurnal variation in the
whole-waveform reproducibility (p<0.01) (Acoustics Australia
April 2006).  David Kemp did a prospective study (reported at
the 2008 mechanics meeting in Keele) and concluded there was
a diurnal variation in CEOAEs.  Food for thought.