>We all know that any sound can be cancelled out by its harmonic. A simple
>circuit can do this. Ron Blue
>The harmonic of a sound would actually increase the overall sound.
The sound that is to be eliminated must be shifted 180 degrees then
reintroduced into the environment in such a way that it reaches the
ears of the person at the same time as the original sound. A
particular automobile uses this concept in a muffler where the exhaust
sound is inverted and fed back into the system through special