Microprocessor implementation of an LPC-based isolated word recognizer

A digital-based isolated word recognition system has been implemented in a module of dedicated hardware that uses a microprocessor and programmable digital signal processing circuitry. The recognizer is based upon the minimum prediction residual principle of Itakura. The recognition algorithm has been developed and tested on a general-purpose minicomputer and array processor, where it has been shown to be suitable for several recognition tasks. The recognition hardware consists of an Intel 8086 16-bit microprocessor operating in parallel with a digital speech processing peripheral (DSPP) tailored to the algorithm. The microprocessor performs the supervisory and decision operations; the DSPP performs the 200,000T + 4,500N multiply-add operations (and associated data transfers) associated with the recognition of a word of duration T sec from an N word vocabulary with 1 template per word. The recognizer is compact (board area of 250 sq. in.) and inexpensive (commercial component cost of about $1200 for 40 word templates).