Yahoo is beta-testing a new audio search engine service. It allows users to search for audio files including music from major online music stores and podcasts.

Yahoo! said the free service indexes more than 50 million audio files, including podcasts, newscasts, speeches and interviews, along with music tracks in different formats, such as MP3 or ACC.

The service is similar to that offered by AOL’s Singing Fish and Blinkx, but Yahoo! claims to be the only service to index downloadable songs offered by most of the key digital music services.

Don’t expect Yahoo always returns accurate results, as it is still in beta. A search for some popular podcasts didn’t rank the podcast files in the top search results.

Via NetImperative: Yahoo! tests audio search engine. Test Yahoo Audio Search Beta.

If successful, this could be used to index audio content including podcasts, which index is then suitable for podcast promotion, just like a natural search index for web sites.

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