A pilot program introduced today by Washington state uses Microsoft Research technology to search, by keyword, thousands of hours of audio from legislative hearings dating back to the 1970s. It's great news for historians and for anyone who wants to listen, over the Internet, to an elaborate discussion of salmon habitat during a 1982 House Agriculture Committee hearing.

The project demonstrates one of the ways the Redmond company is trying to expand its presence in the key area of Internet search.

That won't comfort open-source software advocates and others who worry that governmental agencies already rely too heavily on Microsoft. Running the service requires the state to use Windows Server and other back-end Microsoft technologies.

The search interface is available to the public here, by choosing the Audio Recordings record series in the drop-down menu.

The service builds on the state's efforts to digitize more than 30,000 cassette tapes from House hearings. More than 6,000 hours of audio are currently available for searching online, covering hearings from 1973 to 2001. Another 10,000 hours are expected to be made available for searching over the next two years, the state says.

Microsoft's technology analyzes the audio to create a rough text file -- not an accurate transcript but good enough for keyword searches. The state is also thinking about using the technology to analyze the audio tracks on archived videos -- letting people search those by keyword, too.

"For us, this is a big breakthrough," said Steve Excell, assistant secretary of state, explaining that the state considered it important not only to preserve the audio but also to give the public an easy way of accessing it.

Excell said the state is already a heavy user of Microsoft technology, and it's not worried about the possibility of being locked into the company's products in this case. He noted that the state generally keeps raw files in non-proprietary formats, and it could always switch to another audio-search technology it finds another offering with similar or better functionality in the future.

The technology was developed in Microsoft's Beijing research lab, by research lead Frank Seide and researcher Kit Thambiratnam. The company is offering the technology on a non-commercial basis for the pilot program, but other governmental agencies elsewhere have also expressed an interest, and Microsoft is looking into ways to turn the technology into a product in the future, said Behrooz Chitsaz, director of intellectual property strategy for Microsoft Research.

"The whole archiving thing is very, very big in government today, because these tapes are starting to go bad, and they're national treasures,"  Chitsaz said. "Once you archive them, you have to be able to get at them -- and that's where this technology comes in."