What Is Automatic Speech Recognition and Who Uses It?1

Paul De Palma Department of Computer Science Gonzaga University Spokane, WA [email protected] Research into automatic speech recognition (ASR) has a long history dating to the earliest days of computing. It began roughly at the same time that researchers first developed compilers for the early high-level programming languages. Bell Labs, RCA Research, and MIT’s Lincoln labs all used new ideas in acoustic-phonetics to work on the recognition of single digits, syllables, and certain vowel sounds. Work continued through the 1960s in the United States, Japan, and the Soviet Union, using pattern-recognition techniques. This work received a big boost after the development of linear predictive coding in the 1970s, a technique used to represent a compressed version of an acoustic signal. In all cases, however, the effort was to develop systems that could recognize single words. Two developments in the 1980s gave systems their modern shape. The first was Defense Advanced Research Products Agency (DARPA) funding for research into large vocabulary continuous speech recognition (LVCSR). LVCSR systems have vocabularies in the 20,000 to 60,000 word range 2 and, in theory, recognize continuous speech from multiple speakers. The second was the adaptation of statistical