Clever workaround to silence the iOS camera shutter sound (stackoverflow.com)

Very nice!

This is what volvo did in order to cancel out the audible engine noise in their early cars. At least thats what I heard from pitk.

I believe this is also how active noise cancelling headphones work. Take audio, negate sample amplitude, playback with original at the same time.

1 + -1 = 0 aka. phase cancellation