Michael L. Mcmahan

Low cost speech recognition system and method

A low cost speech recognition system generates frames of received speech having binary feature components. The received speech frames are compared with reference templates, and error values representing the difference between the received speech and the reference templates are generated. At the end of an utterance, if one template resulted in a sufficiently small error value, the word represented by that template is selected as the recognized word.

Connected word recognition enrollment method

A method for generating connected word templates begins with generating isolated word templates of selected words. The isolated word templates are used to extract a continuous word template from a segment of continuous speech containing the selectd words. Both the isolated word templates and the connected word templates can be used to generate speech to determine the quality of the generated templates through aural judgment.

Connected word recognizer on a multiprocessor system

Speech recognition algorithms employing a similarity measure between the input speech utterance and the stored reference patterns to determine recognition of a word/sentence are computationally intensive. The instantaneous vocabulary size that can be handled in real-time is relatively small. This limitation can be alleviated by either using multiple programmable processors or by using special purpose hardware to handle the computation-intensive tasks. In a research environment the former approach is preferred, because improvements to the algorithm can rapidly be incorporated and their effects studied in real-time. Texas Instruments has developed a multiple-processor architecture based on the TMS32020 DSP, called Odyssey, that interfaces with Explorer, a symbolic computer. This paper addresses the issues involved in partitioning and allocating tasks in a multiple-processor environment to maximise throughput, and discusses the implementation of a grammar-driven speaker-dependent connected-word recognizer (GDCWR) as an example application that uses the power of multiple processors.

Speech processing using programmable VLSI

A single board speech processing architecture has been developed which incorporates the functions required to provide a general purpose speech input/output capability, including analog filtering, A/D and D/A conversion, signal processing, and data buffering. These functions are implemented using three new integrated circuits: a signal processing chip (SPC) performs the digital signal processing function, an analog input chip (AIC) provides a complete analog input channel, and an analog output chip (AOC) provides the analogous output channel. The resulting Peripheral Speech Processor (PSP) card is a flexible tool which can be applied to a variety of speech processing tasks.