Napster announced today that it has struck a deal with Loudeye Technologies to aid in Napster's struggle to filter out songs. Napster intends to use audio fingerprints provided by Loudeye to filter and track files shared on the Napster network. Loudeye is not the author behind the fingerprinting technology Napster is using, but instead Loudeye's purpose is to do the actual fingerprinting using Relatable's technology. Napster made a deal with Relatable earlier this year.
The audio fingerprint is created by reading audio frequencies at several points in a song, and creating an identifier based on the frequency data. This identifier can then be used to look up a song from a database. Napster has already begun to receive fingerprint data from Loudeye, and is constanty adding the data to its filtering efforts.