Microphone configurations for eyewear devices, systems, apparatuses, and methods
Systems and methods are described to extract desired audio from an apparatus to be worn on a user's head. An apparatus includes a head wearable device and an array of at least three microphones. The at least three microphones are arranged along a plurality of at least two non-parallel axes. Selection logic is configured to identify a selected axis from the plurality and two microphones from the array that form the selected axis. A beamformer is configured to accept as inputs, signals from the two microphones and to output a main microphone channel and a reference microphone channel.
1. An apparatus to be worn on a user's head, comprising:
a head wearable device;
an array of at least three microphones, the at least three microphones are arranged along a plurality of at least two non-parallel axes, wherein a first microphone and a second microphone of the array define a first axis of the plurality of at least two non-parallel axes, wherein the second microphone and a third microphone define a second axis of the plurality of at least two non-parallel axes, and wherein the first microphone and the second microphone are located on an inside surface of a first temple of the head wearable device and the third microphone is located on a bottom surface of the first temple;
selection logic, the selection logic is configured to identify a selected axis from the plurality and two microphones from the array that form the selected axis; and
a beamformer, the beamformer is configured to accept as inputs, signals from the two microphones and to output a main microphone channel and a reference microphone channel.
2. The apparatus of claim 1 , wherein the selection logic uses a metric to identify the selected axis.
3. The apparatus of claim 2 , wherein the metric includes a microphone that receives a maximum sound pressure level.
4. The apparatus of claim 3 , wherein the metric includes a microphone that receives a minimum sound pressure level.
5. The apparatus of claim 2 , wherein the selection logic is configured to monitor the metric and to select a new selected axis from the plurality based on a new value for the metric.
6. The apparatus of claim 2 , wherein the metric is a maximum signal-to-noise ratio difference for the two microphones.
7. The apparatus of claim 1 , further comprising:
a switch, the selected axis is selected based on a state of the switch.
8. The apparatus of claim 1 , wherein the main microphone channel and the reference microphone channel are input to a two-stage noise cancellation block.
9. The apparatus of claim 1 , further comprising:
a speaker, the speaker is coupled to the head wearable device and is configured to provide a signal that the user can hear.
10. The apparatus of claim 9 , wherein when the selected axis does not point towards the user's mouth, the main microphone channel and the reference microphone channel are used to create a signal that is input into the speaker.
11. The apparatus of claim 1 , the array further comprising:
a fourth microphone, the fourth microphone is located on a second temple of the head wearable device and the first microphone and the fourth microphone form a third axis, the second microphone and the fourth microphone form a fourth axis and the third axis is different from the fourth axis, the selection logic to select an active direction from one of at least the first axis, the second axis, and the third axis.
12. An apparatus to be worn on a user's head, comprising:
a head wearable device, the head wearable device further comprising:
an array of three microphones, the array is coupled to the head wearable device, wherein a first microphone and a second microphone of the array define a first axis, wherein the second microphone and a third microphone define a second axis, and wherein the first microphone and the second microphone are located on an inside surface of a first temple of the head wearable device and the third microphone is located on a bottom surface of the first temple;
a speaker, the speaker is coupled to the head wearable device and is configured to provide a signal that the user can hear; and
selection logic, the selection logic to select an active direction from the first axis and the second axis, wherein:
when the active direction is the first axis, outputs from the first microphone and the second microphone are to be processed for transmission from the head wearable device; and
when the active direction is the second axis, outputs from the second microphone and the third microphone are to be processed for use as an input to the speaker.
13. The apparatus of claim 12 , the array further comprising:
a fourth microphone, the fourth microphone is located on a second temple of the head wearable device and the first microphone and the fourth microphone form a third axis, the second microphone and the fourth microphone form a fourth axis and the third axis is different from the fourth axis, the selection logic to select an active direction from one of at least the first axis, the second axis, and the third axis.
14. An apparatus to be worn on a user's head, comprising:
a head wearable device, the head wearable device is configured to be worn on the user's head;
a first microphone, the first microphone is coupled to an inside surface of a first temple of the head wearable device to receive a first acoustic signal from a sound source;
a second microphone, the second microphone is coupled to the inside surface of the first temple of the head wearable device to receive a second acoustic signal from the sound source;
a third microphone, the third microphone is coupled to a bottom surface of the first temple of the head wearable device; and
a beamformer, the beamformer further comprising:
a first input, the first input is configured to receive the first acoustic signal;
a second input, the second input is configured to receive the second acoustic signal;
a main signal output, the beamformer is configured to form a main signal from the first acoustic signal and the second acoustic signal wherein the main signal is formed by steering a main response axis in a first direction, the main signal to be output from the main signal output; and
a reference signal output, the beamformer is configured to form a reference signal from the first acoustic signal and the second acoustic signal wherein the reference signal is formed by steering a reference response axis in a second direction, wherein the first direction is different from the second direction the reference signal to be output from the reference signal output.
15. The apparatus of claim 14 , wherein a first axis formed between the first microphone and the second microphone points towards the user's mouth when the head wearable device is on the user's head.
16. The apparatus of claim 15 , wherein a second axis formed between the first microphone and the second microphone points forward of the user when the head wearable device is on the user's head.
17. The apparatus of claim 16 , wherein a third axis formed between the first microphone and the second microphone points to a side of the user when the head wearable device is on the user's head.
18. The apparatus of claim 17 , further comprising:
selection logic, the selection logic is configured to select the first direction from one of the first axis, the second axis, and the third axis based on a predefined criterion.
19. The apparatus of claim 14 , wherein the main signal is to be input as a main channel to a two-stage noise cancellation unit and the reference signal is to be input as a reference channel to the two-stage noise cancellation unit.
20. An apparatus to be worn on a user's head, comprising:
a head wearable device, the head wearable device is configured to be worn on the user's head;
a first microphone, the first microphone is coupled to an inside surface of a first temple of the head wearable device to receive a first acoustic signal from a sound source, the first microphone is first distance from the sound source;
a second microphone, the second microphone is coupled to an inside surface of the first temple of the head wearable device to receive a second acoustic signal from the sound source, the second microphone is second distance from the sound source;
a third microphone, the third microphone is coupled to a bottom surface of the first temple of the head wearable device; and
a beamformer, the beamformer further comprising:
a first input, the first input is configured to receive the first acoustic signal;
a second input, the second input is configured to receive the second acoustic signal;
a main signal output, the beamformer is configured to form a main signal from the first acoustic signal and the second acoustic signal wherein the main signal is formed by steering a main response axis in a first direction, the main signal to be output from the main signal output; and
a reference signal, the second acoustic signal is used for the refence signal and the second distance is greater than the first distance.