IP Library Granted Patent US 11,722,818
Granted Patent B2
US 11,722,818 · App. 17/645,971 · Granted Aug 8, 2023

Method and apparatus for recognizing wind noise of earphone, and earphone

Inventors: Jiudong Wang (Beijing, CN); Song Liu (Beijing, CN)
Assignee: LITTLE BIRD CO., LTD
H04R3/005H04R1/1083H04R2410/07
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Quick Facts
Patent No.
US 11,722,818
App. No.
17/645,971
Granted
Aug 8, 2023
Kind
B2
Abstract

An earphone includes a feedforward microphone located outside ear and a feedback microphone located inside ear. A method for recognizing wind noise of the earphone includes: feedforward microphone signal collected by feedforward microphone and feedback microphone signal collected by feedback microphone are acquired; Fourier transform is performed on feedforward and feedback microphone signals to obtain a feedforward microphone frequency domain signal and a feedback microphone frequency domain signal; inverse feedback filtering processing is performed on the feedback microphone frequency domain signal to obtain an inverse feedback filtering processing result; inverse feedforward filtering processing is performed on the feedforward microphone frequency domain signal and the inverse feedback filtering processing result to obtain an inverse hybrid filtering processing result; and a wind noise recognition result of the earphone is obtained based on an interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result.

Claims (150)

1. A method for recognizing wind noise of an earphone, the earphone comprising a feedforward microphone located outside an ear and a feedback microphone located inside the ear, wherein the method comprises:

acquiring a feedforward microphone signal collected by the feedforward microphone and a feedback microphone signal collected by the feedback microphone;

performing Fourier transform on the feedforward microphone signal and the feedback microphone signal to obtain a feedforward microphone frequency domain signal and a feedback microphone frequency domain signal;

performing inverse feedback filtering processing on the feedback microphone frequency domain signal to obtain an inverse feedback filtering processing result;

performing inverse feedforward filtering processing on the feedforward microphone frequency domain signal and the inverse feedback filtering processing result to obtain an inverse hybrid filtering processing result; and

obtaining a wind noise recognition result of the earphone based on an interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result,

wherein the inverse feedback filtering processing is implemented through the following formula:

FB

invfb

=

FBmic

×

(

1

-

H

fb

×

G

)

,

wherein FB invfb is the inverse feedback filtering processing result, FBmic is the feedback microphone frequency domain signal, H fb is a frequency response of a feedback filter used when feedback noise cancellation of the earphone is enabled at a current time, and G is a transfer function from a loudspeaker inside the earphone to the feedback microphone; and

the inverse feedback filtering processing is implemented by the following formula:

FB

inv

=

FB

invfb

-

FFmic

×

H

ff

×

G

,

wherein FB inv is the inverse hybrid filtering processing result, FFmic is the feedforward microphone frequency domain signal, H ff is a frequency response of a feedback filter used when feedforward noise cancellation of the earphone is enabled at the current time, and G is the transfer function from the loudspeaker inside the earphone to the feedback microphone.

2. The method of claim 1 , further comprising: after the inverse feedback filtering processing result and the inverse hybrid filtering processing result are obtained,

acquiring a loudspeaker sound source frequency domain signal played by a loudspeaker inside the earphone; and

performing acoustic echo cancellation processing on the inverse feedback filtering processing result and the inverse hybrid filtering processing result according to the loudspeaker sound source frequency domain signal.

3. The method of claim 1 , wherein obtaining the wind noise recognition result of the earphone based on the interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result comprises:

calculating a ratio of energy of the inverse hybrid filtering processing result to energy of the inverse feedback filtering processing result;

if the ratio is greater than a first preset threshold value, determining the wind noise recognition result of the earphone as absence of the wind noise; and

if the ratio is less than a second preset threshold value, determining the wind noise recognition result of the earphone as presence of the wind noise, wherein the first preset threshold value is greater than the second preset threshold value.

4. The method of claim 3 , wherein a frequency band with an apparent effect of the feedforward noise cancellation is selected for energy calculation and comparison in the calculating step.

5. The method of claim 1 , wherein the feedback microphone frequency domain signal is directly determined as the inverse feedback filtering processing result when only the feedforward noise cancellation is enabled.

6. The method of claim 1 , further comprising:

after the wind noise recognition result of the earphone is obtained,

suppressing the wind noise in one or more manners of: reducing a gain of the feedforward microphone, turning off the feedforward microphone, or performing attenuation on a low-frequency signal of the feedforward microphone signal collected by the feedforward microphone.

7. An apparatus for recognizing wind noise of an earphone, the earphone comprising a feedforward microphone located outside an ear and a feedback microphone located inside the ear, wherein the apparatus comprises:

a processor; and

a memory configured to store instructions executable by the processor, wherein the processor is configured to:

acquire a feedforward microphone signal collected by the feedforward microphone and a feedback microphone signal collected by the feedback microphone;

perform Fourier transform on the feedforward microphone signal and the feedback microphone signal to obtain a feedforward microphone frequency domain signal and a feedback microphone frequency domain signal;

perform inverse feedback filtering processing on feedback microphone frequency domain signal to obtain an Inverse feedback filtering processing result;

perform inverse feedforward filtering processing on the feedforward microphone frequency domain signal and the inverse feedback filtering processing result to obtain an inverse hybrid filtering processing result; and

obtain a wind noise recognition result of the earphone based on an interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result,

wherein the inverse feedback filtering processing is implemented through the following formula:

FB

invfb

=

FBmic

×

(

1

-

H

fb

×

G

)

,

wherein FB invfb is the inverse feedback filtering processing result, FBmic is the feedback microphone frequency domain signal, H fb is a frequency response of a feedback filter used when feedback noise cancellation of the earphone is enabled at a current time, and G is a transfer function from a loudspeaker inside the earphone to the feedback microphone; and

the inverse feedback filtering processing is implemented by the following formula:

FB

inv

=

FB

invfb

-

FFmic

×

H

ff

×

G

,

wherein FB inv is the inverse hybrid filtering processing result, FFmic is the feedforward microphone frequency domain signal, H ff is a frequency response of a feedback filter used when feedforward noise cancellation of the earphone is enabled at the current time, and G is the transfer function from the loudspeaker inside the earphone to the feedback microphone.

8. The apparatus of claim 7 , wherein the processor is further configured to: after the inverse feedback filtering processing result and the inverse hybrid filtering processing result are obtained,

acquire a loudspeaker sound source frequency domain signal played by a loudspeaker inside the earphone; and

perform acoustic echo cancellation processing on the inverse feedback filtering processing result and the inverse hybrid filtering processing result according to the loudspeaker sound source frequency domain signal.

9. The apparatus of claim 7 , wherein in order to obtain the wind noise recognition result of the earphone based on the interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result, the processor is configured to:

calculate a ratio of the energy of inverse hybrid filtering processing result to energy of the inverse feedback filtering processing result;

if the ratio is greater than a first preset threshold value, determine the wind noise recognition result of the earphone as absence of the wind noise; and

if the ratio is less than a second preset threshold value, determine the wind noise recognition result of the earphone as presence of the wind noise, wherein the first preset threshold value is greater than the second preset threshold value.

10. The apparatus of claim 9 , wherein the processor is configured to select a frequency band with an apparent effect of the feedforward noise cancellation for energy calculation and comparison, when the ratio of the energy of the inverse hybrid filtering processing result to the energy of the inverse feedback filtering processing result is calculated.

11. The apparatus of claim 7 , wherein the feedback microphone frequency domain signal is directly determined as the inverse feedback filtering processing result when only the feedforward noise cancellation is enabled.

12. The apparatus of claim 7 , wherein the processor is further configured to:

after the wind noise recognition result of the earphone is obtained,

suppress the wind noise in one or more manners of: reducing a gain of the feedforward microphone, turning off the feedforward microphone, or performing attenuation on a low-frequency signal of the feedforward microphone signal collected by the feedforward microphone.

13. An earphone, comprising: a feedforward microphone located outside an ear, a feedback microphone located inside the ear, a loudspeaker, a processor, and a memory that stores computer executable instructions,

wherein the executable instructions, when executed by the processor, cause the processor to implement following steps of:

acquiring a feedforward microphone signal collected by the feedforward microphone and a feedback microphone signal collected by the feedback microphone;

performing Fourier transform on the feedforward microphone signal and the feedback microphone signal to obtain a feedforward microphone frequency domain signal and a feedback microphone frequency domain signal;

performing inverse feedback filtering processing on the feedback microphone frequency domain signal to obtain an inverse feedback filtering processing result;

performing inverse feedforward filtering processing on the feedforward microphone frequency domain signal and the inverse feedback filtering processing result to obtain an inverse hybrid filtering processing result; and

obtaining a wind noise recognition result of the earphone based on an interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result,

wherein the inverse feedback filtering processing is implemented through the following formula:

FB

invfb

=

FBmic

×

(

1

-

H

fb

×

G

)

,

wherein FB invfb is the inverse feedback filtering processing result, FBmic is the feedback microphone frequency domain signal, H fb is a frequency response of a feedback filter used when feedback noise cancellation of the earphone is enabled at a current time, and G is a transfer function from a loudspeaker inside the earphone to the feedback microphone; and

the inverse feedback filtering processing is implemented by the following formula:

FB

inv

=

FB

invfb

-

FFmic

×

H

ff

×

G

,

wherein FB inv is the inverse hybrid filtering processing result, FFmic is the feedforward microphone frequency domain signal, H ff is a frequency response of a feedback filter used when feedforward noise cancellation of the earphone is enabled at the current time, and G is the transfer function from the loudspeaker inside the earphone to the feedback microphone.

14. The earphone of claim 13 , wherein the executable instructions, when executed by the processor, implement further steps of: after the inverse feedback filtering processing result and the inverse hybrid filtering processing result are obtained,

acquiring a loudspeaker sound source frequency domain signal played by a loudspeaker inside the earphone; and

performing acoustic echo cancellation processing on the inverse feedback filtering processing result and the inverse hybrid filtering processing result according to the loudspeaker sound source frequency domain signal.

15. The earphone of claim 13 , wherein obtaining the wind noise recognition result of the earphone based on the interrelationship between the inverse feedback filtering processing result and the inverse hybrid filtering processing result comprises:

calculating a ratio of energy of the inverse hybrid filtering processing result to energy of the inverse feedback filtering processing result;

if the ratio is greater than a first preset threshold value, determining the wind noise recognition result of the earphone as absence of the wind noise; and

if the ratio is less than a second preset threshold value, determining the wind noise recognition result of the earphone as presence of the wind noise, wherein the first preset threshold value is greater than the second preset threshold value.

16. The earphone of claim 15 , wherein a frequency band with an apparent effect of the feedforward noise cancellation is selected for energy calculation and comparison in the calculating step.

17. The earphone of claim 13 , wherein the feedback microphone frequency domain signal is directly determined as the inverse feedback filtering processing result when only the feedforward noise cancellation is enabled.

18. The earphone of claim 13 , wherein the executable instructions, when executed by the processor, implement further steps of:

after the wind noise recognition result of the earphone is obtained,

suppressing the wind noise in one or more manners of: reducing a gain of the feedforward microphone, turning off the feedforward microphone, or performing attenuation on a low-frequency signal of the feedforward microphone signal collected by the feedforward microphone.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 10, 2023
From: BEIJING XIAONIAO TINGTING TECHNOLOGY CO., LTD
To: LITTLE BIRD CO., LTD
Reel/Frame 062334/0788 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 24, 2021
From: WANG, JIUDONG; LIU, SONG
To: BEIJING XIAONIAO TINGTING TECHNOLOGY CO., LTD.
Reel/Frame 058579/0570 →
Priority Claims (1)
CN 202011559834.8 · Dec 25, 2020 · national
Continuity (1)
Related Publication 20220210552A1 · Jun 30, 2022
Cited By (2)
US 12,237,994 US 12,537,757