The use of speech knowledge in automatic speech recognition

In automatic speech recognition, the acoustic signal is the only tangible connection between the talker and the machine. While the signal conveys linguistic information, this information is often encoded in such a complex manner that the signal exhibits a great deal of variability. In addition, variations in environment and speaker can introduce further distortions that are linguistically irrelevant. This paper has three aims: 1) to discuss the nature of variabilities; 2) to describe the kinds of speech knowledge that may help us understand variabilities; and 3) to advocate and suggest specific procedures for the increased utilization of speech knowledge in automatic speech recognition.