wjm@lcuxc.UUCP (B. Mitchell) (01/18/85)
In re several comments about the upper limit of 20 KHz that I referred to in an earlier posting, I strongly suspect that homo sapiens can perceive sounds greater than 20 KHz and that these sounds affect our perception of music, although the music may not have any fundamental frequencies above 15 KHz or so, the harmonics may add a siginificant effect to them. As for the confusion about harmonics, as Mark Terribile points out, ears are non-linear devices, and they seem to be able to perceive harmonics in the 25-30 kHz range, if not higher as "something" - things sound different when passed through a low-pass filter with a cut-off at 20 KHz (of course, filters, especially analog ones do have an effect on the signal and this may be doing something as well). Thus, harmonics may be perceptable even if a fundamental tone of the same frequency would not be. I've always been more pleased by digital recordings (which admittedly have been converted back to analog prior to transfer to LP form) using the Soundstream system with its 50 KHzz sampling rate, than by Denon recordings which I've also heard in LP form that used a master tape made with a 44.1 KHz sampling rate. Apparantly, the extra 3 KHz does make a difference. Regards, Bill Mitchell (ihnp4!lcuxc!wjm)