An audio fingerprint is extracted from an audio sample, where the fingerprint contains information that is characteristic of the content in the sample. The fingerprint may be generated by computing an energy spectrum for the audio sample, resampling the energy spectrum logarithmically in the time dimension,...http://www.google.com/patents/US7516074?utm_source=gb-gplus-sharePatent US7516074 - Extraction and matching of characteristic fingerprints from audio signals
