Exactly what I was looking for, thank you.
Interestingly, the wavelength of sound and the wavelength of wifi signals are in the same ballpark. 900MHz electromagnetic waves come out to ~30cm waves, which is about 1000Hz in sound-in-air.
Exactly what I was looking for, thank you.
Interestingly, the wavelength of sound and the wavelength of wifi signals are in the same ballpark. 900MHz electromagnetic waves come out to ~30cm waves, which is about 1000Hz in sound-in-air.
just my lay person thought here.
But if you could cancel the noise/signal perfectly and everywhere wouldn't that sorta violate energy conservation?
The sound energy has to go somewhere right?
You are providing the energy by emitting the counter signal in the first place.
That's an interesting question: what to do with the energy, ideally? Maybe convert it to very low frequency, so it only annoys elephants.
Perfectly? Surely that is not reasonable?
Even imperfectly, the problem remains - and is answered by the "the energy of the cancellation source counterbalances the noise energy."