AMBIENT NOISE COMPENSATION SYSTEM ROBUST TO HIGH EXCITATION NOISE

• US 20090287482A1
• Filed: 05/22/2009
• Published: 11/19/2009
• Est. Priority Date: 12/22/2006
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: QNX Software Systems Limited (Canada) (Blackberry Limited)
• Inventors: Hetherington, Phillip A.
• Granted Patent: US 8,335,685 B2
• Time in Patent Office: Days
• US Class Current: 704/226
• CPC Class Codes: G10L 21/0208 Noise filtering
• CPC Class Codes: G10L 25/78 Detection of presence or absence of voice signals switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10

Abstract

A speech enhancement system controls the gain of an excitation signal to prevent uncontrolled gain adjustments. The system includes a first device that converts sound waves into operational signals. An ambient noise estimator is linked to the first device and an echo canceller. The ambient noise estimator estimates how loud a background noise would be near the first device before or after an echo cancellation. The system then compares the ambient noise estimate to a current ambient noise estimate near the first device to control a gain of an excitation signal.

Claims

1. A speech enhancement system, comprising:

a first device that converts sound waves into operational signals;

an ambient noise estimator coupled to the first device; and

an echo canceller coupled to the first device and the ambient noise estimator to dampen a sound;

where the ambient noise estimator estimates how loud a background noise would be near the first device prior to the echo cancellation and then compares the estimate to a current ambient noise estimate near the first device to control a gain of an excitation signal.

2. The speech enhancement system of claim 1 where a comparator compares estimates of the background noise and the current ambient noise estimate.

3. The speech enhancement system of claim 2 where the gain of the excitation signal is controlled at an output of a device that converts electric signals into an audible sound.

4. The speech enhancement system of claim 2 where the comparator is configured to differentiate between an ambient noise and a composite noise.

5. The speech enhancement system of claim 1 where the gain of the excitation signal is controlled at an output of a device that converts electric signals to an audible sound.

6. The speech enhancement system of claim 1 where the ambient noise estimator comprises a transducer.

7. The speech enhancement system of claim 1 further comprising a transceiver in communication with a sink that is remote from the first device and the echo canceller.

8. The speech enhancement system of claim 1 where the first device is compliant with a transceiver protocol of a remote source and a remote sink is compliant with a transceiver protocol of a transceiver that is local to, and receives an output from the echo canceller.

9. The speech enhancement system of claim 8 where the remote source and the remote sink comprises a unitary device.

10. The speech enhancement system of claim 8 where the transceiver and echo canceller comprises part of a hands free phone system.

11. The speech enhancement system of claim 1 where the ambient noise estimator is configured to estimate noise based on an enclosure'"'"'s coupling factor.

12. A speech enhancement system, comprising:

a first device that converts sound waves into operational signals;

an ambient noise estimator coupled to the first device; and

an echo canceller coupled to the first device and the ambient noise estimator to dampen a sound;

where the ambient noise estimator estimates a level of a background noise near the first device after an echo cancellation and then compares the estimate to a current ambient noise estimate near the first device to control a gain of an excitation signal.

13. The speech enhancement system of claim 12 where a comparator compares estimates of the background noise and the current ambient noise estimate.

14. The speech enhancement system of claim 13 where the gain of the excitation signal is controlled at an output of a device that converts electric signals into an audible sound.

15. The speech enhancement system of claim 13 where the comparator is configured to differentiate between an ambient noise and a composite noise.

16. The speech enhancement system of claim 12 where the gain of the excitation signal is controlled at an output of device that converts electric signals to an audible sound.

17. The speech enhancement system of claim 12 where the ambient noise estimator comprises a transducer.

18. The speech enhancement system of claim 12 further comprising a transceiver in communication with a sink that is remote from the first device and the echo canceller.

19. The speech enhancement system of claim 12 where the first device is compliant with a transceiver protocol of a remote source and a remote sink is compliant with a transceiver protocol of a transceiver that is local to, and receives an output from the echo canceller.

20. The speech enhancement system of claim 19 where the remote source and the remote sink comprises a unitary device.

21. The speech enhancement system of claim 19 where the transceiver and echo canceller comprises part of a hands free phone system.

22. The speech enhancement system of claim 12 where the ambient noise estimator is configured to estimate noise based on a coupling factor.