Patent ID: 6868380
Filing Date: 2005-03-15
Classification: G06Q,G10L

Abstract:
1. A speech recognition system for transforming an acoustic signal into a stream of phonetic estimates, comprising: a frequency analyzer for receiving the acoustic signal and producing as an output a short-time frequency representation of the acoustic signal; a novelty processor for receiving the short-time frequency representation of the acoustic signal, separating one or more background components of the representation from one or more region-of-interest components of the representation, and producing a novelty output including the region of interest components of the representation according to one or more novelty parameters; an attention processor for receiving the novelty output and producing a gating signal as a predetermined function of the novelty output according to one or more attention parameters; a coincidence processor for receiving the novelty output and the gating signal, and producing a coincidence output that includes co-occurrences between samples of the novelty output over time and frequency, wherein the coincidence output is selectively gated as a predetermined function of the gating signal, so as to produce a gated coincidence output according to one or more coincidence parameters; and a vector pattern recognizer and a probability processor for receiving the gated coincidence output and producing a phonetic estimate stream representative of acoustic signal; wherein the short-time frequency representation of the audio signal includes a series of consecutive time instances, each consecutive pair separated by a sampling interval, and each of the time instances further includes a series of discrete Fourier transform (DFT) points, such that the short-time frequency representation of the audio signal includes a series of DFT points; wherein for each DFT point, the novelty processor (i) calculates a first average value across a first predetermined frequency range and a first predetermined time span, (ii) calculates a second average value across a second predetermined frequency range and a second predetermined time span, and (iii) subtracts the second average value from the first average value so as to produce the novelty output point; and wherein the first frequency range, the first time span, the second frequency range and the second time span are each a function of one or more of the novelty parameters.