On Wed, 11 Mar 2015 19:46:25 GMT, (Don Pearce) wrote:

On Thu, 12 Mar 2015 06:40:05 +1100, Trevor Wilson
wrote:


**Well, it would, wouldn't it? Phase shift and all that.... The human
hearing system is exquisitely sensitive to phase shift.


The human hearing system is essentially totally deaf to phase shift.
I've seen an experiment in which the phase of the harmonics of a
square wave was cyclically shifted. You could see the waveform
changing shape on a scope. Even with the picture in view, it was
impossible to hear any change in the resulting sound.

Deafness to phase shift is the reason why Orban's Optimod system is
able to operate inaudibly.

d

I've managed to recreate something like it. Have a listen, then look
at the waveform on an audio editor. This will show you how human
hearing deals with phase shift.

http://www.soundthoughts.co.uk/listen/phase.mp3

d