开云体育

Hi Barry,
No sighs from my desk, your question is a good one. I think these modern headphones work in the following manner, a small amount of noise comes through the leather in your headphones. At the same time the external noise is picked up by a small microphone in the headset, amplified by an inverting amplifier and added to the direct noise to you ear in equal amounts. The noise is thus attenuated. And it does work, I have one such headphone from a well-known company.
G?ran