Amazon Technologies, Inc.

Kenneth Edgar Hild, Ii

Amit Singh Chhetri

Kavitha Velusamy

William Folwell Barton

Ramya Gopalan

Michael Alan Pogue

Robert Ayrapetian

The systems, devices, and processes described herein may identify a beam of a voice-controlled device that is directed toward a reflective surface, such as a wall. The beams may be created by a beamformer. An acoustic echo canceller (AEC) may create filter coefficients for a reference sound. The filter coefficients may be analyzed to identify beams that include multiple peaks. The multiple peaks may indicate presence of one or more reflective surfaces. Using the amplitude and the time delay between the peaks, the device may determine that it is close to a reflective surface in a direction of the beam.

Beam rejection in multi-beam microphone systems

A multi-channel echo cancellation system that dynamically adapts to changes in acoustic conditions. The system does not require a sequence of 'start-up' tones to determine the impulse responses. Rather, the adaptive filters approximate estimated transfer functions for each channel. A secondary adaptive filter adjusts cancellation to adapt to changes in the actual transfer functions over time after the adaptive filters have been trained, even if the reference signals are not unique relative to each other.

Multichannel acoustic echo cancellation with unique individual channel estimations

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Cupertino, CA, United States of America

Kenneth Edgar Hild, Ii