The Tritone Paradox

An applet demonstrating the Tritone Paradox. I unambiguously perceive the first tone as lower than the second at both frequencies. Most people perceive the first tone as higher than the second when both are played at 110 Hz, but the second as higher than the first (which is correct) at 160 Hz. I poked around Diana Deutsch’s website a bit hoping she had something on whether people with perfect pitch are susceptible to the paradox. It would seem that they would have to be unsusceptible to it, by the definition of perfect pitch. And it would also explain why I was not fooled by it. But then I was fooled by the Shepard’s Tones illusion. Evidently if the transitions are finely-grained enough, my pitch-discerning abilities fail as well. When I hear the next octave and try to recall the previous octave, I can hear that there’s something fishy; that it doesn’t sound as high as it should be. But I cannot help but hear the transition from one note to the next as increasing in pitch. I wonder if people who have never been exposed to music (much less trained to recognise relative pitches) are susceptible to the Shepard’s Tones illusion. Is there a chance that they will hear the frequency rather than the musical note?

More thoughts: if, as Deutsch postulates, people’s interpretations of the Tritone Paradox are dependent on their native languages, what bearing does this have on the disproportionate occurrence of perfect pitch amongst autistic people? Keep in mind that one of the symptoms of autism is an impairment of verbal ability. Not all autistic people are impaired in that respect, but certainly there exist musical savants with perfect pitch who are impaired thus. Perhaps language “interferes” with one’s absolute pitch recognition abilities? But that would not explain why speakers of more tonal languages like Chinese are also more likely to have perfect pitch. Here we have the situation where perfect pitch, which is surmised to be linked to language somehow, occurs disproportionately in a group of people who mostly have impaired verbal abilities, and in another group of people who have had special training in recognising pitches in verbal interaction.