JHC
Chief assistant to the assistant chief
Hear is a link to test you frequency perception by ear can you distinguish between 440 and 446 I can just make it out but not every time and my hearing has deteriorated with age but 452 should be obvious to everyone.
http://www.fretsource.com/Flash progs/Pitchsense.html
http://www.fretsource.com/Flash progs/Pitchsense.html