Pattern-forming microphone array

Patent metadata

Field	Value
Publication number	US-11523212-B2
Application number	US-201916409239-A
Country	US
Kind code	B2
Filing date	May 10, 2019
Priority date	Jun 1, 2018
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Embodiments include a microphone array with a plurality of microphone elements comprising a first set of elements arranged along a first axis, comprising at least two microphone elements spaced apart by a first distance; a second set of elements arranged along the first axis, comprising at least two microphone elements spaced apart by a second, greater distance, such that the first set is nested within the second set; a third set of elements arranged along a second axis orthogonal to the first axis, comprising at least two microphone elements spaced apart by the second distance; and a fourth set of elements nested within the third set along the second axis, comprising at least two microphone elements spaced apart by the first distance, wherein each set includes a first cluster of microphone elements and a second cluster of microphone elements spaced apart by the specified distance.

First claim

What is claimed is:

1. A microphone array, comprising:
a plurality of microphone elements comprising:
a first set of elements arranged along a first axis and comprising a first cluster of two or more microphone elements spaced apart from a second cluster of two or more microphone elements by a first distance;
a second set of elements arranged along the first axis and comprising a third cluster of two or more microphone elements spaced apart from a fourth cluster of two or more microphone elements by a second distance greater than the first distance, such that the first set is nested within the second set;
a third set of elements arranged along a second axis orthogonal to the first axis, the third set comprising a fifth cluster of two or more microphone elements spaced apart from a sixth cluster or two or more microphone elements by the second distance; and
a fourth set of elements nested within the third set along the second axis, the fourth set comprising a seventh cluster of two or more microphone elements spaced apart from an eighth cluster of two or more microphone elements by the first distance,

wherein the first distance is selected for optimal microphone operation in a first frequency band, and the second distance is selected for optimal microphone operation in a second frequency band that is lower than the first frequency band, and
wherein within each cluster, the two or more microphone elements are arranged adjacent to each other and symmetrically about the corresponding axis.

2. The microphone array of claim 1 , wherein each cluster included in the first set contains two microphone elements, and each cluster included in the second set contains four microphone elements.

3. The microphone array of claim 1 , wherein for each set of elements, the second cluster corresponds with the first cluster in terms of number and arrangement of microphone elements.

4. The microphone array of claim 1 , wherein a center of the first axis is aligned with a center of the second axis, and each set of microphone elements is symmetrically arranged relative to the orthogonal axis.

5. The microphone array of claim 1 , wherein the third and fourth sets of elements correspond to the first and second sets of elements, respectively, in terms of number and arrangement of microphone elements.

6. The microphone array of claim 1 , wherein the plurality of microphone elements further comprises:
a fifth set of elements comprising at least two microphone elements spaced apart from each other by a third distance along the first axis, the third distance being greater than the second distance, so that the second set is nested within the fifth set, wherein the third distance is selected for optimal microphone operation in a third frequency band that is lower than the second frequency band.

7. The microphone array of claim 1 , wherein a select one of the first and second sets is placed on a first surface of the microphone array, and the remaining set is placed on a second surface opposite the first surface.

8. The microphone array of claim 7 , wherein the first surface is a back face of the microphone array and the second surface is a front face thereof.

9. The microphone array of claim 1 , wherein each microphone element is a micro-electrical mechanical system (MEMS) microphone.

10. A microphone system, comprising:
a microphone array including a plurality of microphone elements coupled to a support, the plurality of microphone elements comprising first and second sets of elements arranged along a first axis of the support, the first set being nested within the second set,
wherein the first set includes a first cluster of two or more microphone elements spaced apart from a second cluster of two or more microphone elements by a first distance selected to configure the first set for optimal microphone operation in a first frequency band, and the second set includes a third cluster of two or more microphone elements spaced apart from a fourth cluster of two or more microphone elements by a second distance that is greater than the first distance, the second distance being selected to configure the second set for optimal microphone operation in a second frequency band that is lower than the first frequency band, and
wherein within each cluster, the two or more microphone elements are arranged adjacent to each other and symmetrically about said first axis;
a memory configured to store program code for processing audio signals captured by the plurality of microphone elements and generating an output signal based thereon;
at least one processor in communication with the memory and the microphone array, the at least one processor configured to execute the program code in response to receiving audio signals from the microphone array,
wherein the program code is configured to:
receive audio signals from each microphone element of the microphone array;
for each cluster in a given set, sum the audio signals received from the two or more microphone elements in the cluster to generate a cluster signal;

for each set of elements along the first axis, combine the cluster signals for the clusters in the set to generate a combined output signal with a directional polar pattern; and
combine the combined output signals for the first and second sets to generate a final output signal for all of the microphone elements on the first axis.

11. The microphone system of claim 10 , wherein combine the cluster signals for each set of elements comprises:
subtract the cluster signals to generate a first signal;
sum the cluster signals to generate a second signal; and
sum the first and second signals to generate the combined output signal.

12. The microphone system of claim 10 , wherein for each set of elements, the clusters correspond with each other in terms of number and arrangement of microphone elements.

13. The microphone system of claim 10 , wherein the plurality of microphone elements further comprises third and fourth sets of elements arranged along a second axis of the support orthogonal to the first axis, the third set being nested within the fourth set, and the third and fourth sets corresponding to the first and second sets, respectively, in terms of number and arrangement of microphone elements, and wherein the program code is further configured to:
for each set of elements along the second axis, combine the audio signals for the microphone elements in the set to create a combined output signal with a directional polar pattern;
combine the combined output signals for the third and fourth sets to generate a final output signal for the microphone elements on the second axis; and
combine the final output signal of the first axis with the final output signal of the second axis to produce a final combined output signal with a planar directional polar pattern.

14. The microphone system of claim 10 , wherein the program code is further configured to:
prior to generating the output signal, apply crossover filtering to the combined output signals so that each set of elements on the first axis optimally covers the frequency band associated therewith.

15. The microphone system of claim 14 , wherein the plurality of microphone elements further comprises a fifth set of elements comprising at least two microphone elements spaced apart from each other by a third distance along the first axis, the third distance being larger than the second distance, so that the second set is nested within the fifth set, wherein the third distance is selected to configure the fifth set for optimal microphone operation in a third frequency band that is lower than the second

Assignees

• Shure Acquisition Holdings Inc

Inventors

• Ansai Michelle Michiko
• Gibbs John Casey
• Abraham Mathew T

Classifications

• H04R2201/405

  Non-uniform arrays of transducers or a plurality of uniform arrays with different transducer spacing · CPC title

• H04R19/04

  Microphones (H04R19/01 takes precedence) · CPC title

• H04R3/04

  for correcting frequency response · CPC title

• H04R2201/401

  2D or 3D arrays of transducers · CPC title

• H04R1/265

  of microphones · CPC title