Systems and methods for noise cancellation and power management in a wireless headset

• US 20100022283A1
• Filed: 07/25/2008
• Published: 01/28/2010
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Terlizzi, Jeffrey J.
• Granted Patent: US 8,285,208 B2
• Time in Patent Office: Days
• US Class Current: 455/570
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: G10L 21/0216 characterised by the method used for estimating noise
• CPC Class Codes: H04B 2001/3866 carried on the head
• CPC Class Codes: H04M 1/05 specially adapted for use on head, throat or breast
• CPC Class Codes: H04M 1/19 Arrangements of transmitters, receivers, or complete sets to prevent eavesdropping, to attenuate local noise or to prevent undesired transmission; Mouthpieces or receivers specially adapted therefor circuit arrangements for preventing eavesdropping H04M1/68; telephone cabinets E04H1/14
• CPC Class Codes: H04M 1/6058 involving the use of a headset accessory device connected to the portable telephone
• CPC Class Codes: H04M 1/6066 including a wireless connection
• CPC Class Codes: H04M 2250/02 including a Bluetooth interface
• CPC Class Codes: H04M 2250/12 including a sensor for measuring a physical value, e.g. temperature or motion
• CPC Class Codes: H04W 52/0277 according to available power supply, e.g. switching off when a low battery condition is detected
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

This includes systems and methods for noise cancellation and power management in a wireless headset. The wireless headset can perform noise cancellation by using two or more omni-directional microphones to generate a noise canceling “cone.” Audio signals received outside of the cone can be filtered out. An accelerometer can be used to determine the location of the wireless headset and the system can then properly position the cone to face the user'"'"'s voice and filter out other audio signals. Additionally, by monitoring the ambient noise, the system can save power by turning off the noise cancellation system when the amount of ambient noise is below a threshold value.

Claims

1. A method comprising:

receiving an audio signal;

determining an amount of ambient noise present in the audio signal;

comparing the amount of ambient noise to a cutoff value; and

operating a noise cancellation system for a wireless headset based on the comparison of the amount of ambient noise to the cutoff value.

2. The method of claim 1, wherein:

comparing the amount of ambient noise to a cutoff value comprises determining that the amount of ambient noise is less than the cutoff value; and

operating a noise cancellation system comprises turning off at least part of the noise cancellation system in response to determining that the amount of ambient noise is less than the cutoff value.

3. The method of claim 2, wherein turning off at least part of the noise cancellation system comprises turning off all but one of a plurality of omni-directional microphones of the noise cancellation system.

4. The method of claim 1, wherein:

comparing the amount of ambient noise to a cutoff value comprises determining that the amount of ambient noise is greater than the cutoff value; and

operating a noise cancellation system comprises turning on the noise cancellation system in response to determining that the amount of ambient noise is greater than the cutoff value.

5. The method of claim 1, wherein operating a noise cancellation system further comprises discarding at least a portion of the audio signal that is received from outside of a cone-shaped region extending from the wireless headset.

6. The method of claim 5, wherein operating a noise cancellation system further comprises:

determining an angular position of the wireless headset; and

determining a size of the cone-shaped region based on the determined angular position.

7. The method of claim 5, wherein discarding at least a portion of the audio signal comprises:

choosing a first microphone and a second microphone from a plurality of omni-directional microphones of the noise cancellation system;

determining a first time when the portion of the audio signal reaches the first microphone;

determining a second time when the portion of the audio signal reaches the second microphone;

determining a time difference between the first time and the second time;

based on the time difference, determining whether the portion of the audio signal is received from outside the cone-shaped region; and

discarding the portion of the audio signal if it is determined that the portion of the audio signal is received from outside of the cone-shaped region.

8. A method comprising:

receiving an audio signal in a wireless headset;

transmitting the audio signal from the wireless headset to a device in communication with the wireless headset;

processing the audio signal in the device; and

controlling a noise cancellation system for the wireless headset based on the processed audio signal.

9. The method of claim 8, wherein the device in communication with the wireless headset comprises a cellular telephone.

10. The method of claim 8, wherein:

processing the audio signal in the device comprises determining that an amount of ambient noise present in the audio signal is less than a cutoff value; and

controlling a noise cancellation system comprises turning off at least part of the noise cancellation system in response to determining that the amount of ambient noise is less than the cutoff value.

11. The method of claim 8, wherein:

processing the audio signal in the device comprises determining that an amount of ambient noise present in the audio signal is greater than a cutoff value; and

controlling a noise cancellation system comprises turning on the noise cancellation system in response to determining that the amount of ambient noise is greater than the cutoff value.

12. The method of claim 8, further comprising:

transmitting a position signal from the wireless headset to the device, wherein the position signal is indicative of the angular position of the wireless headset; and

processing the position signal in the device.

13. The method of claim 8, wherein controlling a noise cancellation system for the wireless headset comprises controlling the noise cancellation system based on the processed position signal.

14. A system comprising:

a wireless headset comprising an input device configured to receive an audio signal; and

a processor that is configured to;

determine an amount of ambient noise present in the audio signal;

compare the amount of ambient noise to a cutoff value; and

operate a noise cancellation system for the wireless headset based on the comparison of the amount of ambient noise to the cutoff value.

15. The system of claim 14, wherein the processor is further configured to:

determine that the amount of ambient noise is less than the cutoff value; and

in response to determining that the amount of ambient noise is less than the cutoff value, turn off at least part of the noise cancellation system.

16. The system of claim 15, wherein:

the input device comprises a plurality of omni-directional microphones; and

the processor is further configured to turn off all but one of the plurality of omni-directional microphones.

17. The system of claim 14, wherein the processor is further configured to:

determine that the amount of ambient noise is greater than the cutoff value; and

in response to determining that the amount of ambient noise is greater than the cutoff value, turn on the noise cancellation system.

18. The system of claim 14, wherein the processor is further configured to discard at least a portion of the audio signal that is received from outside of a cone-shaped region extending from the wireless headset.

19. The system of claim 18, wherein:

the input device comprises an accelerometer configured to generate a position signal indicative of the angular position of the wireless headset; and

the processor is further configured to determine a size of the cone-shaped region based on the position signal.

20. The system of claim 18, wherein:

the input device comprises a plurality of omni-directional microphones; and

the processor is further configured to;

choose a first microphone and a second microphone from the plurality of omni-directional microphones;

determine a first time when the portion of the audio signal reaches the first microphone;

determine a second time when the portion of the audio signal reaches the second microphone;

determine a time difference between the first time and the second time;

based on the time difference, determine whether the portion of the audio signal is received from outside the cone-shaped region; and

discard the portion of the audio signal if it is determined that the portion of the audio signal is received from outside of the cone-shaped region.

21. A system comprising:

a wireless headset that is configured to;

receive an audio signal;

transmit the audio signal from the wireless headset; and

a device in communication with the wireless headset that is configured to;

receive the transmitted audio signal;

process the audio signal; and

control a noise cancellation system for the wireless headset based on the processed audio signal.

22. The system of claim 21, wherein the device in communication with the wireless headset comprises a cellular telephone.

23. The system of claim 21, wherein the processor is further configured to:

determine that an amount of ambient noise present in the audio signal is less than a cutoff value; and

turn off at least part of the noise cancellation system in response to determining that the amount of ambient noise is less than the cutoff value.

24. The system of claim 21, wherein the processor is further configured to:

determine that an amount of ambient noise present in the audio signal is greater than a cutoff value; and

turn on the noise cancellation system in response to determining that the amount of ambient noise is greater than the cutoff value.

25. The system of claim 21, wherein:

the wireless headset is further configured to transmit a position signal that is indicative of the angular position of the wireless headset; and

the device is further configured to;

receive the position signal; and

process the position signal.

26. The system of claim 25, wherein the device is further configured to control the noise cancellation system for the wireless headset based on the processed position signal.