SPEECH SIGNAL PROCESSING RESPONSIVE TO LOW NOISE LEVELS

• US 20130211832A1
• Filed: 02/09/2012
• Published: 08/15/2013
• Est. Priority Date: 02/09/2012
• Status: Abandoned Application

• Current Assignee: General Motors LLC (General Motors Company)
• Original Assignee: General Motors LLC (General Motors Company)
• Inventors: Talwar, Gaurav, Sims, Robert D.
• Application Number:
  US13/370,066
• Publication Number:
  US 20130211832A1
• Time in Patent Office: Days
• US Class Current: 704/233
• CPC Class Codes: G10L 15/20 Speech recognition techniques specially adapted for robustness in adverse environments, e.g. in noise, of stress induced speech G10L21/02 takes precedence

Abstract

A method of speech recognition in a vehicle. Audio including noise and a speech signal representative of an utterance from a user is received via a microphone, and a signal-to-noise ratio (SNR) for the received audio is calculated using a processor. It is determined whether the calculated SNR is greater than a predetermined SNR. If so, then a noise distribution is identified for addition to the received audio, and noise corresponding to the identified noise distribution is injected into the received audio to produce noise-injected audio including the speech signal.

Claims

1. A method of speech recognition in a vehicle, the method comprising the steps of:

(a) receiving, via a microphone, audio including noise and a speech signal representative of an utterance from a user;

(b) calculating, via a processor, a signal-to-noise ratio (SNR) for the received audio;

(c) determining whether the calculated SNR is greater than a predetermined SNR and, if so, then;

(d) identifying a noise distribution for addition to the received audio; and

(e) injecting into the received audio, noise corresponding to the identified noise distribution to produce noise-injected audio including the speech signal.

2. The method of claim 1, further comprising the step of:

(f) pre-processing the noise-injected audio to generate acoustic feature vectors.

3. The method of claim 2, further comprising the step of:

(g) decoding the generated acoustic feature vectors to produce hypotheses for the user utterance in the speech signal.

4. The method of claim 3, further comprising the step of:

(h) post-processing the hypotheses to identify the utterance.

5. The method of claim 1, wherein the identified noise distribution corresponds to the vehicle category of the vehicle.

6. The method of claim 5, wherein the identified noise distribution corresponds to the make and model of the vehicle.

7. The method of claim 1, wherein the predetermined SNR is vehicle-specific.

8. The method of claim 7, wherein the vehicle-specific predetermined SNR is based on a correlation of SNR and speech recognition performance in the vehicle during development of an ASR system for the vehicle.

9. The method of claim 8, wherein the identified noise distribution corresponds to the correlation of SNR and speech recognition performance.

10. A computer program product embodied in a computer readable medium and including instructions usable by a computer processor of a speech processing system to cause the system to implement steps of a method according to claim 1.

11. A method of speech recognition in a vehicle, the method comprising the steps of:

(a) receiving, via a microphone, audio including noise and a speech signal representative of an utterance from a user;

(b) calculating, via a processor, a signal-to-noise ratio (SNR) for the received audio;

(c) determining whether the calculated SNR is greater than a vehicle-specific predetermined SNR and, if so, then;

(d) identifying a vehicle-specific noise distribution for addition to the received audio;

(e) injecting into the received audio, noise corresponding to the identified noise distribution to produce noise-injected audio including the speech signal;

(f) pre-processing the noise-injected audio to generate acoustic feature vectors;

(g) decoding the generated acoustic feature vectors to produce hypotheses for the user utterance in the speech signal; and

(h) post-processing the hypotheses to identify the utterance.

12. The method of claim 11, wherein the vehicle-specific predetermined SNR is based on a correlation of SNR and speech recognition performance in the vehicle during development of an ASR system for the vehicle.

13. The method of claim 12, wherein the identified noise distribution corresponds to the correlation of SNR and speech recognition performance.

14. The method of claim 11, wherein the identified noise distribution includes at least one of a uniform, normal, or gaussian distribution.

15. A computer program product embodied in a computer readable medium and including instructions usable by a computer processor of a speech processing system to cause the system to implement steps of a method according to claim 11.