[linux-audio-user] Re: 192kHz

[Wolfgang Woehl]

fons adriaensen <fons.adriaensen at skynet.be>:

> There are certainly instruments that produce sound well
> above 20 kHz. Now to get 'beats' between two of those
> requires something non-linear - just summing them is not
> enough. Our ears are non-linear at high sound levels, so
> in a real performance this could happen. But I don't
> think it will be noticeable at any sane sound levels.

Still don't understand the non-linear part here :/

I make 2 audio files with 400 and 500 hz sine tones and play 
them along (out of ardour). There is clearly audible beat 
frequency, a 100 hz hum and harmonics of that. Checked with 
jaaa: Adding a 99 hz tone to the mix results in another 1 hz 
beat frequency.

Found 
http://hyperphysics.phy-astr.gsu.edu/hbase/sound/beat.html
and there seems to be no reference to non-linearities that 
would be crucial for the phenomenon to come up.

I seem to be missing something obvious and maybe you can throw 
another much appreciated explanation at me?

-- 
Wolfgang