Amazon Technologies, Inc.

Gm Cruise Holdings LLC

Kanthasamy Chelliah

Carlo Murgia

Wai Chung Chu

Berkant Tacer

Andreas Schwarz

Carlos Renato Nakagawa

Amanda Lind

Yu Rao

Xin Chen

Systems and methods for vehicles to communicate with people outside the vehicle. In particular, a two-way communication system is provided including exterior microphone arrays on the vehicle. Calls performed from the exterior of a vehicle can be difficult to implement with acceptable quality in noisy environments. A pipeline having multiple beamformers is provided to improve call quality, where the pipeline operates on the incoming data for each of the microphone arrays. Each beamformer estimates direction of arrival (DOA) of the speech signal, and utilizes the estimated DOA to generate spatial filtering coefficients to filter the signal. A beamformer can be used to generate a one channel output for each microphone array, and a mixer can be used to mix the signal output from each microphone array. The beamformer enables reliable two-way communication with acceptable listening quality and good intelligibility for the remote assistant listening to the captured signal.

Voice pre-processing pipeline for exterior communications on autonomous vehicle

A system configured to improve audio processing by performing dereverberation and noise reduction during a communication session. The system may apply a two-channel dereverberation algorithm by calculating coherence-to-diffuse ratio (CDR) values and calculating dereverberation (DER) gain values based on the CDR values. While the DER gain values may be calculated at a first stage within the pipeline, the device may apply the DER gain values at a second stage within the pipeline. For example, the device may calculate the DER gain values prior to performing residual echo suppression (RES) processing but may apply the DER gain values after performing RES processing, in order to avoid excessive attenuation of the local speech. In addition to removing reverberation, the DER gain values also remove diffuse noise components, reducing an amount of noise reduction required. Thus, the device may soften noise reduction when the DER gain values are applied.

Dereverberation and noise reduction

A system configured to improve audio processing by performing dereverberation and noise reduction during a communication session. The system may apply a two-channel dereverberation algorithm by calculating coherence-to-diffuse ratio (CDR) values and calculating dereverberation (DER) gain values based on the CDR values. While the device calculates the DER gain values prior to performing acoustic echo cancellation (AEC) processing, the device applies the DER gain values after performing residual echo suppression (RES) processing in order to avoid excessive attenuation of the local speech. To improve output speech quality, the device does not apply the DER gain values for nonreverberant signals, when a signal-to-noise ratio (SNR) value is too low, and/or when far-end talk (e.g., remote speech) is present. Dereverberation processing is further improved by using frequency dependent parameters to calculate the DER gain values and by adjusting other gain values when the DER gain values are applied.

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Sunnyvale, CA, United States of America

Kanthasamy Chelliah