anyone heard of this?

[Jamie]

Has anyone heard of a device that will cancel out a certain sound freqency by emitting the opposite sine? frequency?  I think I read about something like this in the corvette to cancel out road noise electronically. Can anyone refer me to a discussion board where I could pose this question?

[Techstuf]

Here is a good start....

http://www.darpa.mil/MTO/sono/noisecontol.html

[Jamie]

Thanks for the reply, I found the real name to what I was looking for by following your link.  I was really looking for "active noise control"  thanks again.