On Mon, 19 Jan 2004 11:24:37 +0000, Ian Molton wrote:

On Mon, 19 Jan 2004 09:32:32 +0000
Don Pearce wrote:

Try 400 and 401 Hz then - far more obvious.

You do not hear a tone at 1Hz in these circumstances - you hear beats.
These are very different. There is no tone, there is no need for any
non-linearity that might generate a tone. You are simply hearing
pressure peaks moving in and out of phase.

Its the same effect though. I agree 1 Hz isnt really a tone, but it is a
signal.

No, it is not even a signal. There is a variation in level at 1Hz, but
absolutely no acoustic energy whatever at that frequency. Have a look
at the two tones on a spectrum analyser and try to find anything at
all going on at 1Hz - you won't find it.

Or are you suggesting that the pressure peaks DONT move in and outr of
phase in the 400/450 case?

Of course they do.
d

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