UNIFIED MICROPHONE PRE-PROCESSING SYSTEM AND METHOD

• US 20120185247A1
• Filed: 12/22/2011
• Published: 07/19/2012
• Est. Priority Date: 01/14/2011
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Tzirkel-Hancock, Eli, Tsimhoni, Omer
• Granted Patent: US 9,171,551 B2
• 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
• CPC Class Codes: G10L 15/22 Procedures used during a speech recognition process, e.g. man-machine dialogue
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: H04M 9/08 Two-way loud-speaking telephone systems with means for conditioning the signal, e.g. for suppressing echoes for one or both directions of traffic
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A unified microphone pre-processing system includes a plurality of microphones arranged within a vehicle passenger compartment, a processing circuit or system configured to receive signals from one or more of the plurality of microphones, and the processing circuit configured to enhance the received signals for use by at least two of a telephony processing application, an automatic speech recognition processing application, and a noise cancellation processing application. The method includes receiving signals from one or more of a plurality of microphones arranged within a vehicle passenger compartment, and enhancing the received signals for use by at least two of a telephony processing application, an automatic speech recognition processing application, and a noise cancellation processing application. A computer readable medium containing executable instructions to cause a processor to perform a method in accordance with an embodiment of the invention is also described.

Claims

1. A unified microphone pre-processing system comprising:

a plurality of microphones arranged within a vehicle passenger compartment;

a processing system configured to receive signals from the plurality of microphones; and

the processing system configured to process the signals to generate enhanced signals for use by at least two of a telephony processing application, an automatic speech recognition processing application, and a noise cancellation processing application.

2. The system of claim 1, the processing system comprising:

an analog-to-digital converter configured to convert analog signals from the plurality of microphones;

a memory unit configured to store the converted analog signals; and

a control processor configured to perform pre-processing enhancement techniques on the converted analog signals.

3. The system of claim 1, wherein the processing system comprises a beamformer unit configured to shape one or more reception beams of the plurality of microphones.

4. The system of claim 3, wherein the beamformer unit is to shape a plurality of reception beams, and to adaptively shape the plurality of reception beams based on changes in acoustic conditions of the vehicle passenger compartment.

5. The system of claim 1, the processing system comprising:

a pre-processing unit configured to perform analog-to-digital conversion on the received signals;

an acoustic echo cancellation pre-processing unit; and

at least two of;

a telephony pre-processing unit configured to enhance the digitized received signals so as to improve reduction of noise and residual echo in a telephone communication;

a speech recognition pre-processing unit configured to enhance the digitized received signals so as to optimize speech recognition metrics including Mel cepstrum distance or word recognition rate; and

a noise cancellation pre-processing unit configured to obtain an accurate measurement of sound pressure and provide the measurement to an active noise cancellation system

6. The system of claim 1, wherein the plurality of microphones are arranged in a geometrical pattern.

7. The system of claim 6, wherein the geometrical pattern is semispherical.

8. The system of claim 1, wherein the processing is system configured to process the signals to generate enhanced signals for use by a noise cancellation processing application by:

locating a target occupant;

retrieving microphone array parameters for locations near the target occupant;

interpolating the array parameters.

9. A method for unified microphone pre-processing, the method comprising:

receiving signals from a plurality of microphones arranged within a vehicle passenger compartment; and

enhancing the received signals for use by at least two of a telephony processing application, an automatic speech recognition processing application, and a noise cancellation processing application.

10. The method of claim 9, further including:

performing pre-processing enhancement techniques on the signals; and

shaping multiple reception beams of the plurality of microphones.

11. The method of claim 10, further including directing the shaped multiple reception beams to at least one of a driver and one or more passengers in a vehicle passenger compartment.

12. The method of claim 9, further including performing enhancement of the received signals for acoustic echo cancellation.

13. The method of claim 9, further including:

performing noise and residual echo reduction by steering at least one of the multiple reception beams to a speaker'"'"'s mouth; and

applying signal enhancement and signal reconstruction techniques.

14. The method of claim 9, further including performing speech recognition enhancement pre-processing on the received signals to optimize speech recognition metrics including Mel cepstrum distance or word recognition rate.

15. The method of claim 9, wherein the plurality of microphones are arranged in a geometrical pattern.

16. The method of claim 9, comprising generating enhanced signals for use by a noise cancellation processing application by:

locating a target occupant;

retrieving microphone array parameters for locations near the target occupant;

interpolating the array parameters.

17. A method comprising:

receiving signals from a plurality of spatially disparate microphones;

processing the signals to produce a processed signal; and

providing the processed signal to a plurality of audio applications, the plurality of audio applications comprising at least two of a telephony application, an automatic speech recognition application, and a noise cancellation application.

18. The method of claim 17, comprising shaping multiple reception beams of the plurality of microphones for one or more of the pre-processing enhancement techniques

19. The method of claim 18, comprising directing the shaped multiple reception beams to at least one of a driver and one or more passengers in a vehicle passenger compartment.

20. The method of claim 17, comprising:

performing enhancement of the received signals for acoustic echo cancellation;

performing noise and residual echo reduction by steering at least one of the multiple reception beams to a speaker'"'"'s mouth, and applying signal enhancement and signal reconstruction techniques;

performing speech recognition enhancement pre-processing on the received signals using Mel cepstrum distance or word recognition rate metrics; and

performing sound pressure measurements near a head of an occupant.