[rescue] Thoughts on system noise...

[Sridhar the POWERful]

On Sun, 24 Mar 2002 Innfomail at aol.com wrote:

> I can't remember the title of the story but in the book "Tales from the White
> Hart" by Arthur C. Clarke an engineer makes a sound canceling machine. IIRC
> this is the same technology used in the new Noise Canceling headphones.
>
> It involves generating sound waves with an opposite Polarity? so that the two
> waves cancel each other out.
>
> It seems to me that this could be applied to both fan sounds and drive whine,
> particularly since they are often constant.
>
> Another opportunity for a creative engineer.

I've built these systems.  It uses sound of the same wave and amplitude,
but opposite phase to cancel the waves out.  It's not easy to engineer
properly.

Peace...  Sridhar