Systems and methods for using a piezoelectric speaker as a microphone in a mobile device

Patent metadata

Field	Value
Publication number	US-10225653-B2
Application number	US-201715675314-A
Country	US
Kind code	B2
Filing date	Aug 11, 2017
Priority date	Mar 14, 2013
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

In accordance with embodiments of the present disclosure, a device may include a piezoelectric speaker for generating sound, a microphone, and a controller communicatively coupled to the speaker and the microphone. The controller may be configured to receive a first signal from the piezoelectric speaker, the first signal induced at least in part by sound incident on the speaker other than sound generated by the piezoelectric speaker, receive a second signal from the microphone, the second signal induced by sound incident on the microphone, process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone, and select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

First claim

What is claimed is:

1. A device comprising:
a piezoelectric speaker for generating sound;
a microphone; and
a controller communicatively coupled to the piezoelectric speaker and the microphone, and configured to:
receive a first signal from the piezoelectric speaker, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
receive a second signal from the microphone, the second signal induced by sound incident on the microphone;
process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone; and
select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

2. The device of claim 1 , wherein the first signal is a voltage signal.

3. The device of claim 1 , wherein the controller is further configured to:
operate the piezoelectric speaker in a first mode wherein the controller communicates an output signal to the piezoelectric speaker for generating sound; and
operate the piezoelectric speaker in a second mode wherein the controller deactivates the piezoelectric speaker from emitting sound and receives the first signal induced by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker and processes the first signal.

4. The device of claim 1 , wherein the controller is further configured to transition the device from a low-power state to a high-power state responsive to a determination that the first signal induced by sound incident on the piezoelectric speaker corresponds to stimulus for transitioning the device from a low-power state to a high-power state.

5. The device of claim 1 , wherein the controller is further configured to:
perform frequency equalization on the first signal and the second signal in order to account for differences in frequency responses to sound incident upon the piezoelectric speaker and the microphone.

6. The device of claim 1 , wherein the at least one characteristic comprises a sound level.

7. The device of claim 1 , wherein the controller is further configured to, based on sound incident at the piezoelectric speaker and sound incident on the microphone, perform beamforming to determine spatial selectivity of sounds incident on the device.

8. The device of claim 1 , wherein the controller is further configured to select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the characteristic comprises selecting at least one of the microphone and the piezoelectric speaker as a signal source based on a volume of sound incident on at least one of the microphone and the piezoelectric speaker and an operational mode of the device.

9. A method comprising:
generating, by a piezoelectric speaker, a first signal, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
receiving a second signal from a microphone, the second signal induced by sound incident on the microphone;
processing at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone; and
selecting at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

10. The method of claim 9 , wherein the first signal is a voltage signal.

11. The method of claim 9 , further comprising:
operating the piezoelectric speaker in a first mode wherein a controller of a device comprising the piezoelectric speaker and the microphone communicates an output signal to the piezoelectric speaker for generating sound; and
operating the piezoelectric speaker in a second mode wherein the controller deactivates the piezoelectric speaker from emitting sound and receives the first signal induced by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker and processes the signal.

12. The method of claim 9 , further comprising transitioning a device comprising the piezoelectric speaker and the microphone device from a low-power state to a high-power state responsive to a determination that the first signal induced by sound incident on the piezoelectric speaker corresponds to stimulus for transitioning the device from a low-power state to a high-power state.

13. The method of claim 9 , further comprising:
performing frequency equalization on the first signal and the second signal in order to account for differences in frequency responses to sound incident upon the piezoelectric speaker and the microphone.

14. The method of claim 9 , wherein the at least one characteristic comprises a sound level.

15. The method of claim 9 , further comprising:
based on sound incident at the piezoelectric speaker and sound incident on the microphone, performing beamforming to determine spatial selectivity of sounds incident on a device comprising the piezoelectric speaker and the microphone.

16. The method of claim 9 , wherein selecting at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the characteristic comprises selecting at least one of the microphone and the piezoelectric speaker as a signal source based on a volume of sound incident on at least one of the microphone and the piezoelectric speaker and an operational mode of a device comprising the piezoelectric speaker and the microphone.

17. An integrated circuit comprising:
a first input configured to receive a first signal from a piezoelectric speaker, the first signal induced at least in part by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker;
a second input configured to receive a second signal from a microphone, the second signal induced by sound incident on the microphone; and
a processing circuit configured to:
process at least one of the first signal and the second signal to determine at least one characteristic of sound incident upon at least one of the piezoelectric speaker and the microphone; and
select at least one of the microphone and the piezoelectric speaker as a signal source for incident sound based on the at least one characteristic.

18. The integrated circuit of claim 17 , wherein the first signal is a voltage signal.

19. The integrated circuit of claim 17 , wherein the processing circuit is further configured to:
operate the piezoelectric speaker in a first mode wherein the processing circuit communicates an output signal to the piezoelectric speaker for generating sound; and
operate the piezoelectric speaker in a second mode wherein the processing circuit deactivates the piezoelectric speaker from emitting sound and receives the first signal induced by sound incident on the piezoelectric speaker other than sound generated by the piezoelectric speaker and processes the first signal.

20. The integrated circuit of claim 17 , wherein the processing circuit is further configured to transition a device from a low-power state to a high-power state responsive to a determination that the first signal induced by sound incident on the piezoelectric speaker corresponds to stimulus for transitioning the device from a low-power state to a high-power state.

Assignees

• Cirrus Logic Inc

Inventors

• Melanson John L
• Swanson Eric

Classifications

• H04W52/0254

  detecting a user operation or a tactile contact or a motion of the device · CPC title

• Y02D70/00

  Cross-Sectional Technologies · mapped topic

• H04W52/0251

  using monitoring of local events, e.g. events related to user activity · CPC title

• H04R3/005 Primary

  for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407) · CPC title

• H04R1/1041

  Mechanical or electronic switches, or control elements (switches in general H01H) · CPC title