Multiple microphone switching and configuration

• US 8,401,178 B2
• Filed: 09/30/2008
• Issued: 03/19/2013
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Chen, Shaohai, Li, Xingqun
• Primary Examiner(s): Jamal, Alexander
• Application Number:
  US12/242,517
• Publication Number:
  US 20100081487A1
• Time in Patent Office: 1,631 Days
• Field of Search: 381/92, 379/406.03, 379/406.02
• US Class Current: 379/406.03
• 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. An apparatus comprising:

a communications device housing having integrated therein;

an uplink channel processor to provide an uplink voice signal for a call by enhancing a voice dominant input signal using an echo or noise dominant input signal;

a downlink channel processor to receive a downlink voice signal for the call;

a plurality of microphones;

a switch to couple (a) a microphone signal, that is selectable from each of the plurality of microphones, into a voice dominant input of the uplink channel processor, and (b) a further microphone signal, selectable from each of the plurality of microphones, into a noise and/or echo dominant input of the uplink channel processor; and

a selector to dynamically control the switch during the call to change the coupling of the microphone signals wherein the selector is to change coupling of the voice dominant input and the noise and/or echo dominant input, based on a current call handling mode of the apparatus, the current call handling mode being one of handset mode and speakerphone mode.

2. The apparatus of claim 1, wherein the switch is to couple an additional microphone signal, selectable from each of the plurality of microphones, into a supplementary input of the uplink channel processor for enhancing the voice dominant input signal.

3. The apparatus of claim 1, wherein the selector is to change coupling of one of the voice dominant input or the noise and/or echo dominant input based on an analysis of microphone signals from the plurality of microphones.

4. The apparatus of claim 3, wherein the selector is to change said coupling of one of the voice dominant input or the noise and/or echo dominant input in response to one micro hone signal having a reduced signal to noise ratio as compared to another one of the microphone signals.

5. The apparatus of claim 1, wherein the selector is to change coupling of one of the voice dominant input or the noise and/or echo dominant input based on a position of the apparatus detected by an accelerometer.

6. The apparatus of claim 1, wherein at least two microphones of the plurality of microphones are not positioned adjacent to each other.

18. The apparatus of claim 1 wherein the selector is to change the coupling of the voice dominant input in response to one microphone signal having reduced signal-to-noise ratio as compared to another.

7. A machine-implemented method comprising the following operations performed in a communications device during a recording session or a call:

analyzing signals from a plurality of microphones;

switching a first coupling of a microphone signal between the plurality of microphones and a voice dominant input based on the analysis of the signals from the plurality of microphones;

switching a second coupling of a further microphone signal between the plurality of microphones and a noise or echo dominant input based on the analysis of the signals from the plurality of microphones; and

enhancing the microphone signal that is coupled to the voice dominant input, by suppressing ambient noise and/or canceling echo based on the microphone signal that is coupled to the noise or echo dominant input, wherein one of said switching a first coupling and a second coupling is based on a current call handling mode of operation of the communications device being one of handset mode and speakerphone mode.

8. The machine-implemented method of claim 7, wherein said switching a first coupling is in response to one microphone having a reduced signal-to-noise ratio as compared to another microphone in the plurality of microphones.

9. The machine-implemented method of claim 7, wherein said switching a second coupling is in response to one microphone having a reduced signal-to-noise ratio as compared to another microphone in the plurality of microphones.

15. The method of claim 7 wherein output signals of unselected ones of the plurality of microphones are ignored while enhancing the microphone signal that is coupled to the voice dominant input.

16. The method of claim 7 wherein the plurality of microphones are more than two microphones and wherein said switching a second coupling is informed through a trial and error procedure that (a) applies microphone signals, from the microphones other than the one associated with the first coupling, to enhance the microphone signal that is coupled to the voice dominant input and (b) evaluates the applied microphone signals to select one that is most likely to enhance the microphone signal that is coupled to the voice dominant input.

10. A telephony device comprising:

a housing having a plurality of microphones;

a selector to dynamically select, during a sound recording or sound communication, one microphone of the plurality of microphones for a voice dominant input and another microphone of the plurality of microphones for a noise or echo dominant input;

a switch coupled to the selector and to the plurality of microphones, to route signals from the selected microphones to said voice dominant and noise or echo dominant inputs; and

a processing component to enhance the signal at the voice dominant input based on the signal at the noise or echo dominant input wherein the plurality of microphones are more than two microphones and wherein the selector'"'"'s dynamic control of the switch is informed through a trial and error procedure that (a) applies microphone signals, other than the one coupled to the voice dominant input by the switch, to enhance the microphone signal that is coupled to the voice dominant input and (b) evaluates the applied microphone signals to select one that is most likely to enhance the microphone signal that is coupled to the voice dominant input.

11. The telephony device of claim 10, wherein output signals of unselected ones of the plurality of microphones are ignored by the processing component while enhancing the voice dominant input signal.

12. The telephony device of claim 10, wherein the selector is to change a selection of the one microphone or the another microphone during the sound recording or sound communication.

13. The telephony device of claim 10, wherein the selection of the one microphone in handset mode differs from the selection of the one microphone in speakerphone mode.

14. The telephony device of claim 10, wherein the processing component is to use each of the plurality of microphones to actively track a voice of a person in the sound recording or sound communication.

17. The telephony device of claim 10, wherein the selector is to select the one microphone and the another microphone based on information from an accelerometer.

19. The telephony device of claim 10, wherein the sound recording or sound communication is a video recording.

20. The telephony device of claim 10, wherein the sound recording or sound communication is a video conference call.