The '70s also marked a few other important milestones in speech recognition technology, including the founding of the first commercial speech recognition company, Threshold Technology, as well as Bell Laboratories' introduction of a system that could interpret multiple people's voices.
1980s: Speech Recognition Turns Toward Prediction
Over the next decade, thanks to new approaches to understanding what people say, speech recognition vocabulary jumped from about a few hundred words to several thousand words, and had the potential to recognize an unlimited number of words. One major reason was a new statistical method known as the hidden Markov model.
Rather than simply using templates for words and looking for sound patterns, HMM considered the probability of unknown sounds' being words. This foundation would be in place for the next two decades (see Automatic Speech Recognition—A Brief History of the Technology Development by B.H. Juang and Lawrence R. Rabiner).
Equipped with this expanded vocabulary, speech recognition started to work its way into commercial applications for business and specialized industry (for instance, medical use). It even entered the home, in the form of Worlds of Wonder's Julie doll (1987), which children could train to respond to their voice. ("Finally, the doll that understands you.")
See how well Julie could speak:
However, whether speech recognition software at the time could recognize 1000 words, as the 1985 Kurzweil text-to-speech program did, or whether it could support a 5000-word vocabulary, as IBM's system did, a significant hurdle remained: These programs took discrete dictation, so you had ... to ... pause ... after ... each ... and ... every ... word.
Next page: Speech recognition for the masses, and the future of speech recognition
1990s: Automatic Speech Recognition Comes to the Masses
In the '90s, computers with faster processors finally arrived, and speech recognition software became viable for ordinary people.