Multiple microphone switching and configuration

• US 9,723,401 B2
• Filed: 03/14/2013
• Issued: 08/01/2017
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Li, Xingqun, Chen, Shaohai
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Zhu, Qin
• Application Number:
  US13/829,934
• Publication Number:
  US 20130216050A1
• Time in Patent Office: 1,601 Days
• Field of Search: None
• 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: G10L 21/0208 Noise filtering
• CPC Class Codes: H04B 3/23 using a replica of transmitted signal in the time domain, e.g. echo cancellers
• CPC Class Codes: H04M 1/035 Improving the acoustic characteristics by means of constructional features of the housing, e.g. ribs, walls, resonating chambers or cavities
• CPC Class Codes: H04M 1/6008 in the transmitter circuit
• CPC Class Codes: H04M 1/605 involving control of the receiver volume to provide a dual operational mode at close or far distance from the user
• 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 3/00 Circuits for transducers , loudspeakers or microphones
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407

Abstract

A mobile communications device contains at least two microphones. One microphone is designated by a selector to provide a voice dominant signal and another microphone is designated to provide a noise or echo dominant signal, for a call or a recording. The selector communicates the designations to a switch that routes the selected microphone signals to the inputs of a processor for voice signal enhancement. The selected voice dominant signal is then enhanced by suppressing ambient noise or canceling echo therein, based on the selected noise or echo dominant signal. The designation of microphones may change at any instant during the call or recording depending on various factors, e.g. based on the quality of the microphone signals. Other embodiments are also described.

Claims

1. A mobile communications apparatus comprising:

a mobile communications handheld device housing having integrated therein three or more microphones; and

a programmed processor that acts as a selector-switch that compares at least one of total harmonic distortion, crosstalk, and side tone for a plurality of near end voice signals from the three or more microphones to designate one of the three or more microphones as the one whose output is a voice dominant input signal and another one of the three or more microphones as the one whose output is an echo or noise dominant input signal, and automatically changes said designation of a pair of microphones, during a call, based on results of said comparisons.

2. The mobile communications apparatus of claim 1 wherein the selector-switch is configured to designate the pair of microphones that provide the voice dominant input signal and the echo or noise dominant input signal, respectively, further based on whether or not there has been a change between a handset operating mode and a speakerphone operating mode during a phone call.

3. The mobile communications apparatus of claim 2 wherein the selector-switch is configured to perform beamforming using the near end voice signals from the three or more microphones to compute an angle at which a speaker of the near end voice signals is located, and designates the pair of microphones that provide the voice dominant input signal and the echo or noise dominant input signal, respectively, further based on the computed angle.

4. The mobile communications apparatus of claim 1 wherein the selector-switch is configured to perform beamforming using the near end voice signals from the three or more microphones to compute an angle at which a speaker of the near end voice signals is located, and designates the pair of microphones that provide the voice dominant input signal and the echo or noise dominant input signal, respectively, further based on the computed angle.

5. The mobile communications apparatus of claim 1 further comprising an accelerometer, wherein the selector-switch is configured to designate the pair of microphones further based on an output signal from the accelerometer.

6. The mobile communications apparatus of claim 2 further comprising an accelerometer, wherein the selector-switch is configured to designate the pair of microphones further based on an output signal from the accelerometer.

7. The mobile communications apparatus of claim 3 further comprising an accelerometer, wherein the selector-switch is configured to designate the pair of microphones further based on an output signal from the accelerometer.

8. The mobile communications apparatus of claim 4 further comprising an accelerometer, wherein the selector-switch is configured to designate the pair of microphones further based on an output signal from the accelerometer.

9. The mobile communications apparatus of claim 1 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

10. The mobile communications apparatus of claim 2 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

11. The mobile communications apparatus of claim 3 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

12. The mobile communications apparatus of claim 4 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

13. The mobile communications apparatus of claim 5 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

14. The mobile communications apparatus of claim 6 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

15. The mobile communications apparatus of claim 7 wherein the selector-switch is configured to perform software routing when switching the designation of the pair of microphones, by providing pointers to microphone streams retrieved from a memory.

16. The mobile communications apparatus of claim 8 wherein the selector-switch is further configured to compare signal-to-noise ratio in addition to the at least one of total harmonic distortion, crosstalk, and side tone for a plurality of near end voice signals from the three or more microphones.

17. A method in a mobile communications apparatus, comprising:

comparing at least one of total harmonic distortion, crosstalk, and side tone for a plurality of near end voice signals received from three or more microphones that are integrated in a housing of the mobile communications apparatus;

designating a signal of one of the three or more microphones as a voice dominant input signal, and a signal of another one of the three or more microphones as an echo or noise dominant input signal, based on said comparisons; and

automatically changing said designation of the voice dominant input signal and the echo or noise dominant input signal, during a call, based on results of said comparisons.

18. The method of claim 17 further comprising:

detecting a change between handset operating mode and speakerphone operating mode during the call, wherein designating the voice dominant input signal and the echo or noise dominant input signal is further based on the change between handset and speakerphone operating modes during the call.

19. The method of claim 17 further comprising comparing signal-to-noise ratio in addition to the at least one of total harmonic distortion, crosstalk, and side tone for a plurality of near end voice signals received from three or more microphones.

20. The method of claim 17 further comprising:

performing beamforming using the three or more microphone signals to compute an angle at which a speaker of the near end voice signals is located, wherein designating the voice dominant input signal and the echo or noise dominant input signal is further based on the computed angle.

21. The method of claim 17 wherein designating the voice dominant input signal and the echo or noise dominant input signal is further based on an output signal from an accelerometer.