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AmazonGranted patentAudio & voiceInterest 4/10

Amazon patents smarter noise cancellation for microphone arrays

This patent describes a method for improving how devices with multiple microphones remove background noise. It adjusts the speed at which the noise-filtering software updates itself based on how loud the sound is and how much noise is present. The system also avoids using nearby sound directions as reference points to ensure the user's voice is not accidentally cancelled out.

Why it mattersThis could lead to clearer voice calls and better voice command recognition on devices like smart speakers or laptops by protecting speech from being filtered away.

In the filing’s own words

A system that improves beam cancellation by refining reference beam selection and dynamically controlling an adaptation speed of adaptive filters. For example, a device may control the adaptation speed by dynamically determining a variable step-size parameter based on a relative strength of a microphone signal and/or a signal-to-noise ratio (SNR) value associated with an individual beam. The device may compare current energy levels of the microphone signal to a range of energy levels to determine a microphone step-size value, track a minimum noise floor to determine an SNR step-size value, and determine the variable step-size parameter using a sigmoid curve. Additionally or alternatively, the device can use a hybrid approach to select reference beams and can perform neighbor exclusion to further protect speech. For example, the device may exclude reference beams that are adjacent to a target beam to prevent the speech from being represented in the reference beams.

What exactly they claim (claim 1)

1. A computer-implemented method, comprising: receiving microphone audio data associated with a microphone array of a device; generating directional audio data using the microphone audio data, the directional audio data comprising: first audio data corresponding to a first direction relative to the device, and second audio data corresponding to a second direction relative to the device, the second direction different from the first direction; determining, using the second audio data and a first plurality of filter coefficient values associated with a first adaptive filter, first reference data; determining first error data using the first reference data and the first audio data; determining a first range of values associated with the microphone audio data and a first time window; determining, using the first range of values and the microphone audio data, a first step-size value of the first adaptive filter, wherein the first step-size value represents a rate at which the first adaptive filter updates filter coefficients over time; and determining, using the first error data, the first step-size value, the second audio data, and the first plurality of filter coefficient values, a second plurality of filter coefficient values associated with the first adaptive filter.

Facts

Company
Amazon (Amazon Technologies, Inc.)
Official title
Adaptive beam cancellation
Patent number
US12739564B1
Application number
18466272
Filed
Sep 13, 2023
Granted
Sep 15, 2026
Inventors
5
Claims
20

Classified under

H04R 5/04 Electricity & electronicsH04R 1/406 Electricity & electronics
Read the full filing (official PDF) ↗ Open in the Patent Tracker

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Summaries are simplified from the filing’s own abstract and first claim. A patent filing is not a product announcement.
Patent data and drawings: U.S. Patent and Trademark Office (USPTO). Nebula is not affiliated with or endorsed by the USPTO.