Recent advances in speech processing

An overview is given of recent advances in the domain of speech recognition. The author focuses on speech recognition, but also mentions some progress in other areas of speech processing (speaker recognition, speech synthesis, speech analysis and coding) using similar methodologies. The problems related to automatic speech processing are identified, and the initial approaches that have been followed in order to address those problems are described. The author then introduces the methodological novelties that allowed for progress along three axes: from isolated-word recognition to continuous speech, from speaker-dependent recognition to speaker-independent, and from small vocabularies to large vocabularies. Special emphasis centers on the improvements made possible by Markov models and, more recently, by connectionist models, resulting in improved performance for difficult vocabularies or in more robust systems. Some specialized hardware is described, as are efforts aimed at assessing speech-recognition systems