Yahoo plans to begin testing its new music search engine today.

Yahoo audio search mines the millions of tracks available through digital music services, including iTunes. It has secured permission from "virtually all" the leading digital music services in order to do this, the company said.

It also carries an index of over 50 million audio files, including podcasts, news broadcasts, speeches and interviews that have been made available online.

Yahoo's director of technology development Bradley Horowitz told Associated Press: "It's really one-stop shopping for the music fan."

He stressed the feature will not offer preferential links to music Yahoo sells through its own services.

"When it comes to search, we're like Switzerland. We can't show bias in search."