Couldn't they ignore noise below a certain threshold and create the signature just based off of the "peaks" and "troughs" so they could expect an exact match, a

Couldn't they ignore noise below a certain threshold and create the signature just based off of the "peaks" and "troughs" so they could expect an exact match, and/or hash several samples from the recording in case some portions don't produce an exact match? Seems like there should be a way to this without revealing information about the recorded sound