This is something which may interest you, but in the Everyday Electronics magazine I read, there have been several circuits that operate upon the following lines: The sound source (usually your walkman or radio) is put into one input of the device, and the noise source (an omnidirectional mike near your earphones, but not so you get a feedback loop) into another. It inverts the background noise wave using an op-amp, so you get the inverse wave form, amplifies (not too much or you'll hear the inverse =) and mixes it with the desired sound source, to give the output. The inverted noise wave cancels out with the actual noise wave, theoretically giving nothing. You can adjust the amplification and some other things. You could actually modify this circuit to cut the noise out from a mike, you have one mike to speak into, and one mike that picks up as much noise and little speech as possible, and the output goes to your sound card. Alternatively, you could use it with a mike I saw mentioned here, that had two parts, one facing to your mouth for speech, and the other, an omni, pointing away to get the noise. All on a little circuit board in your wearable case, and there ya go. Rob -- Subcription/unsubscription/info requests: send e-mail with subject of "subscribe", "unsubscribe", or "info" toWear-Hard Mailing List Archive (searchable): http://wearables.ml.org
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