Here are a couple of related anecdotes.
My piano tuner tells me that he has a customer aged over 80 whose
perfect pitch has gone flat. He has to tune her piano flat in order
that is sounds OK to her. Aparrently she now finds listening to
recordings and the radio unpleasant becaus everything sounds too sharp
to her.
I used to know a classical flute player who at the time was just
starting to get interested in jazz. One evening we went to see some
band and they played Round Midnight, a tune he had never heard before.
He commented that Eb minor was an unusual key for jazz. When I asked
him if he had perfect pitch he said No but he had been playing a
couple of hours earlier so he could still remember the pitch!
Ian.