[1] Practical uses of acoustic fingerprinting include identifying songs, melodies, tunes, or advertisements; sound effect library management; and video file identification.
If two files sound alike to the human ear, their acoustic fingerprints should match, even if their binary representations are quite different.
A robust acoustic fingerprint will allow a recording to be identified after it has gone through such compression, even if the audio quality has been reduced significantly.
Shazam's algorithm picks out points where there are peaks in the spectrogram that represent higher energy content.
[4] When commercial acoustic fingerprinting companies were creating uncertainty over proprietary algorithms in the late 2000s, one of open data service MusicBrainz' contributors, Lukáš Lalinský developed an open source algorithm Chromaprint and the AcoustID service which uses it.