Speaker emulation of a microphone for wind detection

Patent metadata

Field	Value
Publication number	US-2020396539-A1
Application number	US-202016872076-A
Country	US
Kind code	A1
Filing date	May 11, 2020
Priority date	Jun 13, 2019
Publication date	Dec 17, 2020
Grant date	—

Abstract

A method for detecting wind using a microphone and a speaker of an electronic device. The method obtains a microphone signal produced by the microphone. The method obtains a speaker input signal produced by the speaker that is emulating a microphone capturing ambient sound in an environment through the speaker. The method determines a coherence between the microphone signal and the speaker input signal and determines whether the coherence is below a coherence intensity threshold. In response to determining that the coherence is below the coherence intensity threshold, the method determines a presence of wind in the environment.

First claim

What is claimed is:

1 . A method for detecting wind, the method comprising:
obtaining a microphone signal produced by a microphone of an electronic device; obtaining a speaker input signal produced by a speaker that is emulating a microphone to capture ambient sound in an environment through the speaker; determining a coherence between the microphone signal and the speaker input signal; determining whether the coherence is below a coherence intensity threshold; and in response to determining that the coherence is below the coherence intensity threshold, determining a presence of wind in the environment.

2 . The method of claim 1 further comprising estimating noise contained within the microphone signal, wherein obtaining the speaker input signal is in response to the noise exceeding a noise threshold.

3 . The method of claim 1 further comprising applying a pre-shaped filter to the microphone signal and to the speaker input signal to cause an idle coherence over a frequency range between both signals in an absence of wind,
wherein determining whether the coherence is below the coherence intensity threshold is in response to a reduction in the idle coherence.

4 . The method of claim 1 , wherein determining the coherence comprises performing dual-channel analysis upon the microphone signal and the speaker input signal to determine the coherence over a frequency range.

5 . The method of claim 4 , wherein the frequency range is between 1 - 10 k Hz.

6 . The method of claim 4 further comprising
comparing the coherence between the microphone signal and the speaker input signal over the frequency range to a predefined coherence over the frequency range to determine a difference between the coherence and the predefined coherence; and
determining a wind speed of the wind based on the difference.

7 . The method of claim 6 further comprising obtaining sensor data that indicates a physical characteristic of the electronic device, wherein the wind speed of the wind is further based on the physical characteristic of the electronic device,
wherein the physical characteristic comprises at least one of a velocity at which the electronic device is traveling, a direction at which the electronic device is traveling, and an orientation of the electronic device.

8 . The method of claim 1 further comprising compensating for the presence of wind in the environment by performing audio processing operations upon the microphone signal, wherein the audio processing operations comprises at least one of spectrally shaping the microphone signal and applying a gain adjustment to the microphone signal.

9 . A system comprising:
a wearable device comprising a microphone and a speaker; a processor; memory having stored therein instructions which when executed by the processor cause the system to:
obtain a microphone signal from the microphone;
obtain a speaker input signal from the speaker that is emulating a microphone;
determine a coherence between the microphone signal and the speaker input signal;
determine whether the coherence is below a coherence intensity threshold; and
in response to the coherence being below the coherence intensity threshold, determine that wind is present.

10 . The system of claim 9 , wherein the memory stores further instructions to cause the system to estimate noise contained within the microphone signal, wherein the instructions to obtain the speaker input signal is in response to the noise being above a noise threshold.

11 . The system of claim 9 , wherein the memory stores further instructions to apply a pre-shaped filter to the microphone signal and to the speaker input signal to produce a filtered microphone signal and a filtered speaker input signal, wherein spectral content over a frequency range between both filtered signals has an idle coherence in an absence of wind,
wherein the instructions to determine whether the coherence the coherence is below the coherence intensity threshold is in response to a reduction in the idle coherence.

12 . The system of claim 9 , wherein the instructions to determine the coherence comprises performing dual-channel analysis upon the microphone signal and the speaker input signal to determine the coherence over a frequency range.

13 . The system of claim 12 , wherein the frequency range is between 1 - 10 k Hz.

14 . The system of claim 12 , wherein the memory stores further instructions to
compare the coherence between the microphone signal and the speaker input signal over the frequency range to a predefined coherence over the frequency range to determine a difference between the coherence and the predefined coherence; and determine a wind speed of the wind based on the difference.

15 . The system of claim 14 , wherein the memory stores further instructions to obtain sensor data that indicates a physical characteristic of the electronic device, wherein the wind speed is further based on the physical characteristic of the electronic device,
wherein the physical characteristic comprises at least one of a velocity at which the electronic device is traveling, a direction at which the electronic device is traveling, and an orientation of the electronic device.

16 . The system of claim 9 , wherein the memory has further instructions to compensate for the presence of wind by performing audio processing operations upon the microphone signal, wherein the audio processing operations comprises at least one of spectrally shaping the microphone signal and applying a gain adjustment to the microphone signal.

17 . The system of claim 9 , wherein the wearable device comprises a smart watch.

18 . A method for detecting wind, the method comprises:
obtaining a microphone signal produced by a microphone of an electronic device; obtaining a speaker input signal produced by a speaker of the electronic device, while the speaker is emulating a microphone; determining a coherence between the microphone signal and the speaker input signal; and determining a speed of wind at the microphone based on the coherence.

19 . The method of claim 18 further comprising injecting coherent noise over a frequency range into the microphone signal and the speaker input signal to produce a filtered microphone signal and a filtered speaker input signal to cause an idle coherence over the frequency range between both signals in an absence of wind.

20 . The method of claim 19 further comprising determining a presence of wind in response to determining that the idle coherence is below a threshold.

21 . The method of claim 18 , wherein determining the speed of the wind comprises comparing the coherence to a plurality of predefined coherences, each of which is associated with a particular speed of wind.

22 . The method of claim 18 further comprising obtaining sensor data from at least one sensor of the electronic device that indicates a physical characteristic of the electronic device, wherein the wind speed is further based on the physical characteristic of the device,
wherein the physical characteristic comprises at least one of a velocity at which the electronic device is traveling, a direction at which the electronic device is traveling, and an orientation of the electronic device.

Assignees

• Apple Inc

Inventors

• Vitt Nikolas T
• Gorny Joyce E
• Jensen Thomas M
• Gleason Jeffrey N
• Chen Tyrone T

Classifications

• H04R2410/07

  Mechanical or electrical reduction of wind noise generated by wind passing a microphone · CPC title

• G01P5/00

  Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft (application of speed-measuring devices for measuring volume of fluid G01F) · CPC title

• H04R3/04 Primary

  for correcting frequency response · CPC title

• G01P5/24

  by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave · CPC title

• H04R29/004

  for microphones (H04R29/007 takes precedence) · CPC title