Here is a local amazing thing. There is an autistic person here at college who has perfect pitch. He can't remember a piece the next day, so he has someone play the piece for him, then he instantly memorizes the entire piece and the plays it back.
The other day he went to a party and when he introduced himself to the hostess, he commented that she had a frederickson a/c. The woman was astounded and said "Yes, I do. How did you know?" He said he could tell by the hum. He had such a good ear that he could tell the difference between units by the different hums.
boliver