This, of course, is really off topic! I've often wondered about this noise reduction technique, though. It seems that unless the noise cancelling source and the noise source are at the same location, you will not be able to cancel the noise over a large area.It will be cancelled in one location, but move just a little bit and the delays between the two signals change and it's no longer cancelled. I've seen some stuff written about noise cancellation, but don't see how it can work very well. Anyone have any more info? Harold On Tue, 11 Apr 2000 12:49:59 -0300 WF writes: > Hi, > > A student is studyng how to invert some wave... > > He intends to NULL some produced sound...in the factory that he > works have some TEXTIL machines and intends to reduce the noise > produced by them...applyng a inverted wave... > > Does someone have some suggestions about this? Formula, site, > etc... > > I think that is too hard! > > Miguel Wisintainer > ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj.