dvorak@houem.UUCP ( Chuck Dvorak ) (06/21/84)
I fail to see how a human, whose sensitivity to 60 kHz is zero, can discriminate between 20kHz sine- and square-waves, a task that necessitates sensitivity at 60kHz... UNLESS 1. nonlinear distortion is occuring in the audio equipment or 2. nonlinear distortion is occuring in the ear. Of course, both of these occur, but if either of these effects cause the appropriate "adequate stimulus," then the real discrimination being performed is NOT between the waveforms whose fundamental is 20kHz. BTW, at 18 kHz, humans require a sound pressure level that is a million times greater than that required at 1khz (in order to hear anything at all). --Chuck (...houem!dvorak) AT&T Bell Labs