The Watson speech recognition engine

In 1995, AT&T Research (then within Bell Labs) began work on a software-only automated speech recognition system named Watson(TM). The goal was ambitious; Watson was to serve as a single code base supporting applications ranging from PC-desktop command and control through to scalable telephony interactive voice services. Furthermore, the software was to be the new code base for the research group, allowing fast deployment of new algorithmic advances from the lab into the field. A set of C++ objects has been developed which support these objectives. This paper gives an overview of the Watson automatic speech recognizer software architecture, describes the algorithms employed, and provides performance numbers for some sample tasks.