NOISY ENVIRONMENT COMMUNICATION ENHANCEMENT SYSTEM

• US 20080107280A1
• Filed: 10/26/2007
• Published: 05/08/2008
• Est. Priority Date: 05/09/2003
• Status: Active Grant

• Current Assignee: Cerence Inc., Cerence Operating Company (Cerence Inc.)
• Original Assignee: Nuance Communications, Inc. (Microsoft Corporation)
• Inventors: Haulick, Tim, Schmidt, Gerhard
• Granted Patent: US 8,724,822 B2
• Time in Patent Office: Days
• US Class Current: 381/66
• CPC Class Codes: G10L 2021/02082 the noise being echo, reverberation of the speech
• CPC Class Codes: G10L 2021/02165 Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: H04M 9/082 using echo cancellers echo cancellers per se H04B3/23
• CPC Class Codes: H04R 2410/05 Noise reduction with a separate noise microphone
• CPC Class Codes: H04R 2430/23 Direction finding using a sum-delay beam-former
• CPC Class Codes: H04R 2430/25 Array processing for suppression of unwanted side-lobes in directivity characteristics, e.g. a blocking matrix
• 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 communication system enhances communications in a noisy environment. Multiple input arrays convert a voiced or unvoiced signal into an analog signal. A converter receives the analog signal and generates digital signals. A digital signal processor determines temporal and spatial information from the digital signals. The processed signals are then converted to audible sound.

Claims

1. A method that enhances communication in a noisy environment comprising:

receiving input signals from two input arrays, where each of the input arrays comprises two receivers; and

obtaining a wanted signal by a wanted signal beamformer and obtaining a blocking signal by a blocking beamformer.

2. The method of claim 1, where the wanted signal beamformer comprises an adaptive beamformer.

3. The method of claim 1, where processing the input signals further comprises deciding whether a signal of the input signals is transmitted from a wanted signal direction.

4. The method of claim 3, where deciding comprises determining a wanted signal power and a blocking signal power, where the wanted signal beamformer is adapted if the blocking signal power is larger than a predetermined threshold.

5. The method of claim 1, where processing the input signals further comprises detecting speech activity.

6. The method of claim 5, where detecting speech activity comprises determining a wanted signal power, a blocking signal power, and a background noise signal power, and comparing the wanted signal power with the blocking signal power and the background noise signal power.

7. The method of claim 6, where detecting speech activity further comprises comparing the wanted signal powers of the input arrays and determining a highest power.

8. The method of claim 5, where processing the input signals further comprises attenuating the input signals if no speech activity is detected.

9. The method of claim 8, where attenuating the input signals comprises adaptively varying the attenuation in predetermined time steps between a nearly zero attenuation level and a maximum attenuation level.

10. The method of claim 1, where processing the input signals further comprises determining a gain control for the input signals.

11. The method of claim 10, where determining the gain control is performed adaptively.

12. The method of claim 1, further comprising selecting an output channel to output the processed signals.

13. The method of claim 12, where selecting the output channel comprises determining an amplification for each selected output channel.

14. A computer-readable medium that stores instructions executable by a processor comprising:

receiving input signals from two input arrays, where each of the input arrays comprises at least two devices that convert sound into an operational signal; and

obtaining a wanted signal by a wanted signal beamformer and obtaining a blocking signal by a blocking beamformer.

15. The computer-readable medium of claim 14 further comprising detecting speech activity.

16. A communication system comprising:

a plurality of input arrays, where each of the input arrays comprises a plurality of receivers configured to convert sound into input signals;

an analog-to-digital converter that converts the input signals into digital signals; and

a digital signal processor stage that processes the digital signals and provides processed output signals to a plurality of loudspeakers,

where the digital signal processing stage comprises a wanted signal beamformer and a blocking signal beamformer.

17. The communication system of claim 16, where the digital signal processor is programmed to detect speech.

18. The communication system of claim 17, where the digital signal processor is further configured to attenuate the digital signals if no speech is detected.

19. The communication system of claim 16, where the digital signal processing stage is configured to select a loudspeaker from the plurality of loudspeakers that receives the processed output signals.

20. A communication system comprising:

a plurality of input arrays, where each of the input arrays comprises means that convert sound into input signals;

a converter means that converts the input signals into digital signals; and

a processing means that processes the digital signals and provides processed output signals to a plurality of loudspeakers,

where each of the input arrays and each of the loudspeakers are associated with a seat in a vehicle.