The idea of computers that accurately understand human speech has both enticed and frustrated engineers. But now, IBM Research in Yorktown Heights, NY, is undertaking a multiyear project to finally solve all the problems that have kept voice recognition systems from comprehending free-form conversations-and becoming mainstream technology.

In current speech recognition technology, algorithms compare the waveform, an electronic representation of a word, to a master waveform database to develop a short list of possible matches, then select the most commonly used word on that list. IBM is exploring ways to make better matches, including new algorithms that make guesses based on the context of the conversation. IBM researchers have also built a lip-reading video system that reduces errors by one-third, says David Nahamoo, group manager of Human Language Technologies for IBM Research. “We’re combining audio and visual features together, which we’re feeding into our recognition engines,” he says. “We’re learning how to use one to clean up the other.”

Some experts are skeptical. Real-time meeting transcription is still “lab stuff right now,” says Steve McClure, vice president at technology market researcher IDC in Framingham, MA. “I’ve seen IBM demos work fine one time, and another time the damn application wouldn’t work at all.” Nahamoo concedes the initiative needs years of work and lots of luck to reach its goals. But given the speech recognition industry’s history of failing to deliver on its promises, Big Blue’s newest push could provide a few words of encouragement to the struggling technology.