On 31 Jan 2005 01:41:56 GMT, Ignoramus24281
wrote:

On Sun, 30 Jan 2005 17:34:19 -0500, paul v birke wrote:
I think one may have to make one's own

In its most simplist form you invert the signal ( one of maybe a few
fundamental frequencies but just one may be enough) and send to some
speakers nearby thereby cancelling the noise in a zone around your machine.

One needs some kind of electronic guru to help here. Do you have any
handy friends who fit this bill. Maybe analogue more that digital
experience here may help.

I think most industrial gadgets would cost thousands.

Then this is not a practical idea.

You're right, it isn't. Active noise cancellation can be very
effective, but it's a project to do it right and it isn't cheap.
Your approach fits your sit far better. Good job!