Statistically, only 1 in 10,000 people have Perfect Pitch hearing to begin with. For the other 9,999, the "echoic memory" only lasts 4 seconds....
Auditory sensory memory is known as echoic memory. In contrast to iconic memories, which decay very rapidly, echoic memories can last as long as four seconds (Cowan, Lichty, & Grove, 1990).