In article ,
says...

"Jerry G." wrote in message
...
Seimens is supposed to have these. The good ones are fairly expensive,
and they are all very limited in performance. Noise is very complex, and
all the situations are very random.

I had such high hopes when I saw ANC demonstrated with a wood chipper
several years ago. I thought this technology was "right around the corner."

My fondest dream -- I want one inside my PC case. The fan noise is making
me crazy, hour-after-hour, day-after-day.