公开(公告)号：US11386911B1

公开(公告)日：2022-07-12

申请号：US16915037

申请日：2020-06-29

Applicant: Amazon Technologies, Inc.

Inventor： Kanthasamy Chelliah ,  Wai Chung Chu ,  Andreas Schwarz ,  Berkant Tacer ,  Carlo Murgia

IPC: G10L21/0232 ,  H04R3/04 ,  H04R5/04 ,  H04R3/00 ,  G10L21/0208

Abstract: 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.

公开(公告)号：US11259117B1

公开(公告)日：2022-02-22

申请号：US17036807

申请日：2020-09-29

Applicant: Amazon Technologies, Inc.

Inventor： Kanthasamy Chelliah ,  Wai Chung Chu ,  Andreas Schwarz ,  Carlos Renato Nakagawa ,  Berkant Tacer ,  Carlo Murgia

IPC: H04R3/00 ,  G10L21/02 ,  H04R3/02 ,  G10L25/21 ,  G10L15/20

Abstract: 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.