Using pitch during speech recognition post-processing to improve recognition accuracy
View Patent ↗A method of automated speech recognition in a vehicle. The method includes receiving audio in the vehicle, pre-processing the received audio to generate acoustic feature vectors, decoding the generated acoustic feature vectors to produce at least one speech hypothesis, and post-processing the at least one speech hypothesis using pitch to improve speech recognition accuracy. The speech hypothesis can be accepted as recognized speech during post-processing if pitch is present in the received audio. Alternatively, a pitch count for the received audio can be determined, N-best speech hypotheses can be post-processed by comparing the pitch count to syllable counts associated with the speech hypotheses, and the speech hypothesis having a syllable count equal to the pitch count can be accepted as recognized speech.
1. A method of automated speech recognition in a vehicle, the method comprising the steps of:
(a) receiving audio in the vehicle;
(b) pre-processing the received audio to generate acoustic feature vectors;
(c) decoding the generated acoustic feature vectors to produce at least one speech hypothesis;
(d) post-processing the at least one speech hypothesis using pitch to improve speech recognition accuracy, including rejecting the speech hypothesis if pitch is not detected in the received audio and accepting the speech hypothesis when the speech hypothesis is identified as having a syllable count equal to pitch count.
2. The method of claim 1 , wherein the accepted speech hypothesis has the highest confidence score of multiple speech hypotheses having a syllable count equal to the pitch count.
3. A method of automated speech recognition in a vehicle, the method comprising the steps of:
(a) receiving audio in the vehicle;
(b) generating a plurality of speech hypotheses from the received audio;
(c) determining a pitch count for the received audio;
(d) identifying one of the speech hypotheses as having a syllable count equal to the pitch count; and
(e) accepting the identified speech hypothesis as recognized speech for the received audio.
4. A method of automated speech recognition in a vehicle, the method comprising the steps of:
(a) receiving audio in the vehicle;
(b) pre-processing the received audio to generate acoustic feature vectors;
(c) processing the generated acoustic feature vectors to produce N-best speech hypotheses and associated confidence scores and syllable counts;
(d) determining a pitch count for the received audio;
(e) post-processing the N-best speech hypotheses by comparing syllable counts associated with the speech hypotheses to the pitch count; and
(f) accepting as recognized speech a speech hypothesis of the N-best speech hypotheses having a syllable count equal to the pitch count.
5. The method of claim 4 , wherein the accepted speech hypothesis has the highest confidence score of multiple speech hypotheses having a syllable count equal to the pitch count.