Active noise reduction in open ear directional acoustic devices

Patent metadata

Field	Value
Publication number	US-11197083-B2
Application number	US-201916534016-A
Country	US
Kind code	B2
Filing date	Aug 7, 2019
Priority date	Aug 7, 2019
Publication date	Dec 7, 2021
Grant date	Dec 7, 2021

Abstract

An acoustic device includes at least one acoustic transducer disposed such that, in a head-worn state, the at least one acoustic transducer is in an open-ear configuration in which an ear canal of a user of the acoustic device is unobstructed. The acoustic device also includes an array of two or more first microphones that captures audio preferentially from a first direction as compared to at least a second direction different from the first direction, wherein the audio captured using the array is processed and played back through the at least one acoustic transducer, and an active noise reduction (ANR) engine that includes one or more processing devices. The ANR engine is configured to generate a driver signal for the at least one acoustic transducer, the driver signal having phases that reduce effects of audio captured from at least the second direction.

First claim

What is claimed is:

1. An acoustic device comprising:
at least one acoustic transducer disposed such that, in a head-worn state, the at least one acoustic transducer is in an open-ear configuration in which an ear canal of a user of the acoustic device is unobstructed;
an array of two or more first microphones that captures audio preferentially from a first direction as compared to at least a second direction different from the first direction, wherein the audio captured using the array is processed and played back through the at least one acoustic transducer; and
an active noise reduction (ANR) engine comprising one or more processing devices, the ANR engine configured to generate a driver signal for the at least one acoustic transducer, the driver signal having phases that reduce effects of audio captured from at least the second direction, and wherein the ANR engine is configured to reduce the effects of the audio captured from the second direction in a 300-1500 Hz frequency band.

2. The acoustic device of claim 1 , wherein the ANR engine is configured to increase a power ratio of (i) audio signals in the 300-1500 Hz frequency band, as captured from the first direction and (ii) audio signals in the 300-1500 Hz frequency band, as captured from at least the second direction, by at least 5 dB.

3. The acoustic device of claim 1 further comprising at least a second microphone to capture audio from the second direction.

4. The acoustic device of claim 3 , wherein in the head-worn state, the second microphone is located behind a pinna of the user.

5. The acoustic device of claim 1 , further comprising an amplifier circuit configured to process the audio captured using the array.

6. The acoustic device of claim 1 , wherein the at least one acoustic transducer and the array of two or more first microphones are disposed along a temple of an eye-glass frame.

7. The acoustic device of claim 1 , wherein the first direction is an estimated direction of gaze of the user of the acoustic device.

8. The acoustic device of claim 1 , wherein the audio captured using the array is processed using a beamforming process to capture audio from the first direction.

9. The acoustic device of claim 1 , wherein the at least one acoustic transducer and the array of two or more first microphones are disposed in an open-ear headphone.

10. The acoustic device of claim 1 , wherein the at least one acoustic transducer is a part of an array of acoustic transducers.

11. The acoustic device of claim 1 , wherein in the head-worn state, a ratio between (i) an amount of coupling between the at least one acoustic transducer and a microphone, and (ii) an amount of coupling between the at least one acoustic transducer and a location of an ear canal is approximately 0 dB.

12. The acoustic device of claim 1 , wherein in the head-worn state, a mainlobe of a radiation pattern of the at least one acoustic transducer is directed towards the ear canal of the user, and a power ratio of (i) a portion of output of the at least one acoustic transducer radiated towards the ear canal of the user and (ii) a portion of output of the at least one acoustic transducer radiated towards a microphone of the array is at least 10 dB.

13. The acoustic device of claim 1 , wherein the ANR engine comprises an analog to digital converter, an amplifier, compensator, and a digital to analog converter.

14. A set of wearable audio eyeglasses comprising:
a frame comprising:
a frontal region that includes a pair of lens receptacles, and a bridge disposed between the lens receptacles,
a pair of arms extending from the frontal region of the frame;
at least one acoustic transducer disposed in one of the pair of arms, the acoustic transducer configured to direct audio output towards an ear of a user in a head-worn state of the audio eyeglasses;
an array of two or more first microphones that captures audio preferentially from a first direction as compared to at least a second direction different from the first direction; and
an electronics module comprising:
an amplifier circuit that receives the audio captured using the array, and generates a first driver signal for the at least one acoustic transducer based on the audio, and
an active noise reduction (ANR) engine comprising one or more processing devices, wherein the ANR engine generates a second driver signal for the at least one acoustic transducer, the second driver signal having phases that reduce effects of audio captured from at least the second direction, and wherein the ANR engine reduces the effects of the audio captured from the second direction in a 300-1500 Hz frequency band.

15. The wearable audio eyeglasses of claim 14 , wherein the ANR engine is configured to increase a power ratio of (i) audio signals in the 300-1500 Hz frequency band, as captured from the first direction and (ii) audio signals in the 300-1500 Hz frequency band, as captured from at least the second direction, by at least 5 dB.

16. The wearable audio eyeglasses of claim 14 further comprising at least a second microphone to capture audio from the second direction.

17. The wearable audio eyeglasses of claim 16 , wherein in the head-worn state, the second microphone is located behind a pinna of the user.

18. The wearable audio eyeglasses of claim 14 , wherein in the head-worn state, a mainlobe of a radiation pattern of the at least one acoustic transducer is directed towards the ear canal of the user, and a power ratio of (i) a portion of output of the at least one acoustic transducer radiated towards the ear canal of the user and (ii) a portion of output of the at least one acoustic transducer radiated towards a microphone of the array is at least 10 dB.

Assignees

• Bose Corp

Inventors

• Jain Ankita D
• Struzik Ryan C
• McElhone Dale
• Gauger Jr Daniel M

Classifications

• H04R2460/01

  Hearing devices using active noise cancellation · CPC title

• H04R1/1083

  Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06) · CPC title

• G10K2210/1081

  Earphones, e.g. for telephones, ear protectors or headsets · CPC title

• G10K11/178 Primary

  by electro-acoustically regenerating the original acoustic waves in anti-phase · CPC title

• H04R1/105 Primary

  Earpiece supports, e.g. ear hooks (for stereophonic headphones H04R5/0335) · CPC title