Near-field null and beamforming
First Claim
1. An electronic device comprising:
- a speaker; and
a microphone array comprising;
a first microphone positioned a first distance from the speaker;
a second microphone positioned a second distance from the speaker, wherein the first and second microphones are configured to receive an acoustic signal and wherein the second microphone is located closer to the speaker than the first microphone; and
a complex vector filter coupled to the second microphone, wherein the complex vector filter is applied to an output signal of the second microphone to generate an acoustic sensitivity pattern for the array that provides an acoustic null at the location of the speaker,wherein the complex vector filter comprises a gain factor A to compensate for an amplitude difference between the output signal of the second microphone and the output signal from the first microphone,wherein the gain factor A is a ratio of the distance between the second microphone and the speaker and the distance between the first microphone and the speaker,wherein the gain factor A is less than one, andwherein the microphone array functions as a unidirectional microphone in a near-field and the microphone array functions as an omnidirectional microphone in a far-field.
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Accused Products
Abstract
Devices and methods are disclosed that allow for selective acoustic near-field nulls for microphone arrays. One embodiment may take the form of an electronic device including a speaker and a microphone array. The microphone array may include a first microphone positioned a first distance from the speaker and a second microphone positioned a second distance from the speaker. The first and second microphones are configured to receive an acoustic signal. The microphone array further includes a complex vector filter coupled to the second microphone. The complex vector filter is applied to an output signal of the second microphone to generate an acoustic sensitivity pattern for the array that provides an acoustic null at the location of the speaker.
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Citations
16 Claims
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1. An electronic device comprising:
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a speaker; and a microphone array comprising; a first microphone positioned a first distance from the speaker; a second microphone positioned a second distance from the speaker, wherein the first and second microphones are configured to receive an acoustic signal and wherein the second microphone is located closer to the speaker than the first microphone; and a complex vector filter coupled to the second microphone, wherein the complex vector filter is applied to an output signal of the second microphone to generate an acoustic sensitivity pattern for the array that provides an acoustic null at the location of the speaker, wherein the complex vector filter comprises a gain factor A to compensate for an amplitude difference between the output signal of the second microphone and the output signal from the first microphone, wherein the gain factor A is a ratio of the distance between the second microphone and the speaker and the distance between the first microphone and the speaker, wherein the gain factor A is less than one, and wherein the microphone array functions as a unidirectional microphone in a near-field and the microphone array functions as an omnidirectional microphone in a far-field. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of operating an electronic device to functionally provide an acoustic near-field unidirectional microphone and a far-field omnidirectional microphone, the method comprising:
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receiving an acoustical signal at an acoustic transducer array, wherein the acoustic transducer array comprises a first microphone and a second microphone; generating, by the first microphone, a first electrical signal; generating, by the second microphone, a second electrical signal; and filtering the second electrical signal using a complex vector filter to generate an acoustic sensitivity pattern for the transducer array that provides an acoustic null at the location of a speaker, wherein the complex vector filter comprises a gain factor A to compensate for an amplitude difference between the output signal of the second microphone and the output signal from the first microphone, wherein the second microphone is located closer to the speaker than the first microphone, wherein the gain factor A is a ratio of the distance between the second microphone and the speaker and the distance between the first microphone and the speaker, and wherein the gain factor A is less than one, and wherein the acoustic transducer array functions as a unidirectional microphone in a near-field and the acoustic transducer array functions as an omnidirectional microphone in a far-field. - View Dependent Claims (15, 16)
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Specification