By BRIAN BERGSTEIN AP Technology Writer
BOSTON (AP) -- Suddenly the universe of downloadable audio files known as podcasts seems as enormous as the Internet. Name a topic _ from the weather in Asuncion to the ZigBee wireless technology _ and there is a podcast about it.
But while the Internet's vastness is accessible because of deep-probing search engines, comparably authoritative services for podcasts and other multimedia haven't really emerged.
That's because search programs are primed to catalog text. When they encounter an audio or video file, generally they determine the contents by reading the titles and other descriptive tags, known as "metadata," that creators voluntarily add.
It's useful, but much like examining only the first few lines of a Web site. Reading the whole thing is a lot better.
With that in mind, a few companies are trying to make search engines actually listen to big audio and video files. From there, speech-to-text software can generate written transcripts, which are searched in addition to metadata.
Perhaps best known has been Blinkx Inc., an information-management startup that gets its speech-to-text software from Autonomy Corp.
Now comes BBN Technologies Inc., a defense contractor that developed elements of the Internet. After tinkering with speech-to-text programs it created for U.S. intelligence services, BBN has produced Podzinger, a Web service that mines the content of podcasts.
A third service, Podscope, from a broadcast-monitoring company called TV Eyes Inc., performs a similar trick, but with a twist. CEO David Ives says Podscope uses some voice-recognition technology but mainly scans for phonemes _ the individual sounds that make up syllables _ rather than full words.
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