Acoustic fingerprinting

Acoustical fingerprinting analyzes the actual content of an audio file, as opposed to a written description of what is contained within it (e.g., "metadata”). This means that the filtering tool “listens” to the sound recording, and creates a twenty-second “fingerprint” that can then be compared against any other file that an end-user is attempting to upload or download. If the suspected file has that precise sequence (or spectrum) of sounds, the uploading or downloading of the song will be blocked.