Dual-use bilateral microphone array

• US 10,250,977 B2
• Filed: 03/02/2018
• Issued: 04/02/2019
• Est. Priority Date: 11/09/2016
• Status: Active Grant

• Current Assignee: Bose Corporation
• Original Assignee: Bose Corporation
• Inventors: terMeulen, Ryan, Stockton, X, Andrew Jackson
• Primary Examiner(s): Tran, Thang V
• Application Number:
  US15/910,881
• Publication Number:
  US 20180192191A1
• Time in Patent Office: 396 Days
• CPC Class Codes: G10L 2021/02166 Microphone arrays; Beamforming
• CPC Class Codes: G10L 21/028 using properties of sound source
• CPC Class Codes: H04R 1/1016 Earpieces of the intra-aural type
• CPC Class Codes: H04R 1/1075 Mountings of transducers in earphones or headphones
• CPC Class Codes: H04R 1/1083 Reduction of ambient noise active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06
• CPC Class Codes: H04R 1/406 microphones
• CPC Class Codes: H04R 2201/107 Monophonic and stereophonic headphones with microphone for two-way hands free communication
• CPC Class Codes: H04R 2410/07 Mechanical or electrical reduction of wind noise generated by wind passing a microphone
• CPC Class Codes: H04R 2430/21 Direction finding using differential microphone array [DMA]
• CPC Class Codes: H04R 3/005 for combining the signals of two or more microphones specially adapted for hearing aids H04R25/407
• CPC Class Codes: H04R 5/033 Headphones for stereophonic communication details thereof, e.g. relating to batteries, cables or control elements H04R1/10

Abstract

A pair of earphones have microphone arrays each including a front microphone and a rear microphone. A processor uses a first set of filters to combine the four microphone signals to generate a far-field signal that is more sensitive to sounds originating a short distance away from the earphones than to sounds close to the apparatus, and provides the far-field signal to the speakers for output. The processor also uses a second set of filters to combine the four microphone signals to generate a near-field signal that is more sensitive to voice signals from a person wearing the earphones than to sounds originating away from the earphones, and provides the near-field signal to a communication system.

Claims

1. An apparatus comprising:

a first earphone having a first microphone array, providing a first set of microphone signals, and a first speaker;

a second earphone having a second microphone array, providing a second set of microphone signals, and a second speaker; and

a processor receiving the first set of microphone signals and second set of microphone signals, and configured to;

apply a first set of filters to combine the first and second set of microphone signals to generate a far-field signal that is more sensitive to sounds originating a short distance away from the apparatus than to sounds close to the apparatus;

provide the far-field signal to the speakers for output;

apply a second set of filters to combine the first and second set of microphone signals to generate a near-field signal that is more sensitive to voice signals from a person wearing the earphones than to sounds originating away from the apparatus; and

provide the near-field signal to a communication system.

2. The apparatus of claim 1, wherein the first microphone array and second microphone array are physically arranged to optimize detection of sounds a short distance away from the apparatus.

3. The apparatus of claim 1, wherein the processor is further configured to:

use a third set of filters, different from the second set of filters, to combine the first and second set of microphone signals to generate a second near-field signal that is more sensitive to voice signals from the person wearing the earphones than to sounds originating away from the apparatus; and

provide the second near-field signal to the speakers for output.

4. The apparatus of claim 1, wherein applying the first set of filters comprises:

applying separate filters to each signal from each of the first and second sets of microphone signals to produce a first set of filtered signals;

summing the signals of the first set of filtered signals to produce a first summed signal; and

applying an equalization filter to the first summed signal to generate the far-field signal.

5. The apparatus of claim 1, wherein the processor is further configured to generate the far-field signal and provide the far-field signal to the speakers by:

combining the first and second set of microphone signals, using a third set of filters, different from the first set of filters, to generate a second far-field signal that is more sensitive to sounds a short distance away from the apparatus than to sounds close to the apparatus;

providing the first far-field signal to the first speaker; and

providing the second far-field signal to the second speaker.

6. The apparatus of claim 1, wherein the processor comprises a far-field array sub-processor for applying the first set of filters, and a communication sub-processor for applying the second set of filters, and wherein the sub-processors are configured to generate the near-field signal by:

in the far-field array sub-processor,

summing signals corresponding to a first one of the microphones in the first array and a first one of the microphones in the second array to form a combined front microphone signal, and

summing signals corresponding to a second one of the microphones in the first array and a second one of the microphones in the second array to form a combined rear microphone signal; and

in the communication sub-processor,

filtering the combined front microphone signal to form a filtered combined front microphone signal,

filtering the combined rear microphone signal to form a filtered combined rear microphone signal, and

combining the filtered combined front microphone signal and the filtered combined rear microphone signal to form a directional microphone signal;

the near-field signal comprising the directional microphone signal.

7. The apparatus of claim 1, wherein the processor is further configured to operate the first and second sets of filters simultaneously.

8. The apparatus of claim 1, wherein:

the far-field signal is more sensitive to sounds originating in a first direction than to sounds originating in other directions, and

the processor is further configured to;

apply a third set of filters to combine at least the first set of microphone signals to generate a first anti-noise signal that will cancel sounds at the first earphone when output by the first speaker; and

apply a fourth set of filters to combine at least the second set of microphone signals to generate a second anti-noise signal that will cancel sounds at the second earphone when output by the second speaker.

9. A method comprising, in a processor:

receiving, from a first earphone having a first microphone array, a first set of microphone signals;

receiving, from a second earphone having a second microphone array, a second set of microphone signals; and

combining the first and second set of microphone signals, using a first set of filters, to generate a far-field signal that is more sensitive to sounds originating a short distance away from the first and second earphones than to sounds close to the first and second earphones;

providing the far-field signal to first and second speakers in the respective first and second earphones for output;

combining the first and second set of microphone signals, using a second set of filters, to generate a near-field signal that is more sensitive to voice signals from a person wearing the earphones than to sounds originating away from the first and second earphones; and

providing the near-field signal to a communication system.

10. The method of claim 9, further comprising, in the processor:

combining the first and second set of microphone signals, using a third set of filters, different from the second set of filters, to generate a second near-field signal that is more sensitive to voice signals from the person wearing the earphones than to sounds originating away from the apparatus; and

providing the second near-field signal to the speakers for output.

11. The method of claim 9, wherein applying the first set of filters comprises:

applying separate filters to each signal from each of the first and second sets of microphone signals to produce a first set of filtered signals;

summing the signals of the first set of filtered signals to produce a first summed signal; and

applying an equalization filter to the first summed signal to generate the far-field signal.

12. The method of claim 9, wherein generating the far-field signal and providing the far-field signal to the speakers comprises, in the processor:

using a third set of filters, different from the first set of filters, to combine the first and second set of microphone signals to generate a second far-field signal that is more sensitive to sounds a short distance away from the apparatus than to sounds close to the apparatus;

providing the first far-field signal to the first speaker; and

providing the second far-field signal to the second speaker.

13. The method of claim 9, wherein generating the near-field signal comprises:

in a far-field array sub-processor,

summing signals corresponding to a first one of the microphones in the first array and a first one of the microphones in the second array to form a combined front microphone signal, and

summing signals corresponding to a second one of the microphones in the first array and a second one of the microphones in the second array to form a combined rear microphone signal; and

in a communication processor,

filtering the combined front microphone signal to form a filtered combined front microphone signal,

filtering the combined rear microphone signal to form a filtered combined rear microphone signal, and

combining the filtered combined front microphone signal and the filtered combined rear microphone signal to form a directional microphone signal;

the near-field signal comprising the directional microphone signal.

14. The method of claim 9, further comprising operating the first and second sets of filters simultaneously.

15. The method of claim 9, wherein the far-field signal is more sensitive to sounds originating in a first direction than to sounds originating in other directions, and the method further comprises:

applying a third set of filters to combine at least the first set of microphone signals to generate a first anti-noise signal that will cancel sounds at the first earphone when output by the first speaker; and

applying a fourth set of filters to combine at least the second set of microphone signals to generate a second anti-noise signal that will cancel sounds at the second earphone when output by the second speaker.