Boom cars (ot for sure...)

Joe wrote: [snip] Not to mention the active nose cancellation headsets that I and most of my friends were while flying. They're designed only to deal with low frequency noise; when you turn them on it's like someone stuffed high-pass cotton into your ears. Voices sound perfectly normal but the drone of the engine sounds like it's in the next county. The big problem is power density -- these things only have to provide cancellation in the confines of a headset ear cup. Cancellation in the large would obviously require much higher power levels. I remember when I first heard about something like this, back in the mid-to-late 70's. Some grad student at MIT was working on something he called "the noise sucker", but I don't recall the details. -- Chris Kennedy chris(a)mainecoon.com http://www.mainecoon.com PGP fingerprint: 4E99 10B6 7253 B048 6685 6CBC 55E1 20A3 108D AB97