Quote:
Originally Posted by Doug
I was reading about audio illusions a while back, just a sec - I'll wiki it... hmmm can't seem to find it now... Anyway, there is a famous auditory psycholigist who has studied the psychology of auditory perception. She found that the incidence of perfect pitch may be more prevalent than earlier imagined and that people who have tonal languages as a first language are much more likely to have perfect pitch. Tonal languages, like chinese, Japanese (to a certain extent), Greek ad others alter the meaning of words based on the inflection of the syllables.
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here it is....
The tritone paradox is an auditory illusion created by Diana Deutsch (creator of a number of auditory illusions) based on an earlier suggestion published by Roger Shepard[1]. In the illusion, two Shepard tones separated by exactly half an octave, an equal-tempered tritone, are played alternately. For example, one tone might consist of a roughly 160-Hz sine wave accompanied by sine waves at the higher octaves (320 Hz, 640 Hz, etc.) and lower octaves (80 Hz, 40 Hz, etc.) with energies falling off as a gaussian function of the frequency difference in octaves from 160 Hz. The other tone might consist of a 110-Hz and a 220-Hz sine wave with equal energies, again accompanied by the higher and lower octaves (440 Hz, 55 Hz, etc.) with a gaussian energy distribution.
Shepard predicted that the two tones would constitute a bistable figure, the auditory equivalent of the Necker cube, that could be heard ascending or descending, but never both at the same time. Diana Deutsch later found that perception of which tone was higher depended on the absolute frequencies involved: an individual will usually find the same tone to be higher, and this is determined by the tones' absolute pitches. This is consistently done by a large portion of the population, despite the fact that responding differently to different tones must involve the ability to hear absolute pitch, which was thought to be extremely rare. This finding has been used to argue that latent absolute-pitch ability is present in a large proportion of the population. Deutsch also found that British and Californian subjects consistently resolved the ambiguity the opposite way.