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Re: AW: absolute pitch & animals

The animals were trained to an ultrasonic reference frequency (23 kHz) and learned in a 2-AFC-paradigm to categorize pure tones of varying frequencies to be higher or lower than this reference. After the training period, the reference was omitted and the animals classified the comparison tones only based on the memorized reference. Their performance was remarkable:

Depending on the animals, the absolute pitch discrimination threshold was between 0.4 and 0.8 percent. This is slightly worse than human successive pitch discrimination thresholds (about 0.2 0.6 percent) in the best hearing range under relative pitch conditions. The experiment lasted for about half a year and during that period the animals fully retained this high discrimination performance.

Could humans with AP achieve such fine discrimination thresholds?

I don't know--interesting question. There are surely data out there speaking to this. But note that in this example animals were trained to ONE reference tone only. In order to demonstrate a phenomenon homologous to AP in humans they would have to be able to respond to several dozen reference tones with several dozen unique response categories.

In fact, musicians without AP can sometimes achieve what may be called pseudo-AP in that they develop a long-term memory for a single reference note (e.g., many orchestra musicians can reliably identify A 440 because they've heard it so often). This may be similar to what the bats are able to do.


Robert J. Zatorre, Ph.D.
Montreal Neurological Institute
3801 University St.
Montreal, QC Canada H3A 2B4
phone: 1-514-398-8903
fax: 1-514-398-1338
web site: www.zlab.mcgill.ca