"Bob Myers" wrote in message
...

"Ron Baker, Pluralitas!" wrote in message
...

"Bob Myers" wrote in message
...

"Ron Baker, Pluralitas!" wrote in message
...

First of all, do you think you could possibly learn to trim your posts?

Apparently, no, you can't. Too lazy to take the trouble to
perform this common courtesy, or what?

You could always plonk me.


An audible beat tone is produced by the constructive and destructive
interference between two sound waves in air. Look at a pictorial
representation (in the time domain) of the sum of sine waves,of similar
amplitudes, one at, say, 1000 Hz and the other at 1005, and you'll
see it.

Bob M.


How come you don't hear a 200 Hz beat
with a 1000 Hz tone and a 1200 Hz tone?

For the simple reason that there isn't actually a "tone" involved -
in other words, there is no actual signal at the difference frequency.
There can't be, since there is no "mixing" (multiplication) of the
two original tones.

There is no multiplication of 1000 Hz and 1005 Hz
either, is there? Why don't you hear 1000 Hz and
1005 Hz rather than a single tone varying in amplitude?

The "beat" is really just the perception of
the amplitude variation caused by the interference previously
mentioned. You cannot sense such variations if they occur
rapidly enough, any more than you can detect the flicker of a
light source which is varying rapidly enough.

Bob M.

Could it be that the human auditory system is not
linear?

Ron Baker, Pluralitas! wrote:

Could it be that the human auditory system is not
linear?


No. Humans had to evolve to incorporate a non linear response to sound
when the electronics manufacturers started supplying ONLY non linear
potentiometers for audio equipment use.

This mutation, which is now the norm, was completely unknown before the
start of the twentieth century.

We, here at Densa Labs, call it Darwinian Decibelism



mike

"Ron Baker, Pluralitas!" wrote in message
...
For the simple reason that there isn't actually a "tone" involved -
in other words, there is no actual signal at the difference frequency.
There can't be, since there is no "mixing" (multiplication) of the
two original tones.

There is no multiplication of 1000 Hz and 1005 Hz
either, is there? Why don't you hear 1000 Hz and
1005 Hz rather than a single tone varying in amplitude?

Because you can't distinguish two tones as separate tones
if they are close enough together in frequency, due to the
way in which the frequency-discrimination process in human
hearing operates.


Could it be that the human auditory system is not
linear?

There are a number of ways in which the human auditory
system is not linear; it's simply that these are not the dominant
cause of the perception of audible "beats."

Bob M.