公开(公告)号：US10755728B1

公开(公告)日：2020-08-25

申请号：US15906949

申请日：2018-02-27

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Trausti Thor Kristjansson ,  Philip Ryan Hilmes

IPC: G10L21/038 ,  G10L21/0272 ,  G10L21/0208

Abstract: A system configured to improve noise cancellation by using portions of multiple reference signals instead of using a complete reference signal. The system divides a frequency spectrum into frequency bands and selects a single reference signal from a group of potential reference signals for every frequency band. For example, a first reference signal is selected for a first frequency band while a second reference signal is selected for a second frequency band. The system may generate a combined reference signal using portions of each of the selected reference signals, such as a portion of the first reference signal corresponding to the first frequency band and a portion of the second reference signal corresponding to the second frequency band. Additionally or alternatively, the system may perform noise cancellation using each of the selected reference signals and filter the outputs based on the corresponding frequency band to generate combined audio output data.

公开(公告)号：US20170178662A1

公开(公告)日：2017-06-22

申请号：US14973274

申请日：2015-12-17

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Philip Ryan Hilmes

IPC: G10L21/0216 ,  H04R5/04

CPC classification number: G10L21/0216 ,  G10L21/0208 ,  G10L2021/02082 ,  G10L2021/02166 ,  H04R3/005 ,  H04R5/04 ,  H04R2201/40 ,  H04R2203/12 ,  H04R2420/07

Abstract: An echo cancellation system that performs audio beamforming to separate audio input into multiple directions and determines a target signal and a reference signal from the multiple directions. For example, the system may detect a strong signal associated with a speaker and select the strong signal as a reference signal, selecting another direction as a target signal. The system may determine a speech position and may select the speech position as a target signal and an opposite direction as a reference signal. The system may create pairwise combinations of opposite directions, with an individual direction being selected as a target signal and a reference signal. The system may select a fixed beamformer output for the target signal and an adaptive beamformer output for the reference signal, or vice versa. The system may remove the reference signal (e.g., audio output by the loudspeaker) to isolate speech included in the target signal.

公开(公告)号：US09286883B1

公开(公告)日：2016-03-15

申请号：US14038319

申请日：2013-09-26

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Bjorn Hoffmeister

IPC: H04B3/20 ,  G10K11/178

CPC classification number: G10L21/0208 ,  G10L15/20 ,  G10L2021/02082 ,  H04M9/082

Abstract: Features are disclosed for performing acoustic echo cancellation using random noise. The output may be used to perform speech recognition. Random noise may be introduced into a reference signal path and into a microphone signal path. The random noise introduced into the microphone signal path may be transformed based on an estimated echo path and then combined with microphone output. The random noise introduced into the reference signal path may be combined with a reference signal and then transformed. In some embodiments, the random noise in the reference signal path may be used in the absence of another reference signal, allowing the acoustic echo canceler to be continuously trained.

Abstract translation: 公开了用于使用随机噪声执行声学回波消除的特征。 该输出可用于执行语音识别。 可将随机噪声引入参考信号路径并传入麦克风信号路径。 引入麦克风信号路径的随机噪声可以基于估计的回波路径而变换，然后与麦克风输出组合。 引入参考信号路径的随机噪声可以与参考信号组合，然后变换。 在一些实施例中，参考信号路径中的随机噪声可以在不存在另一个参考信号的情况下使用，从而允许连续训练声学回波消除器。

公开(公告)号：US09172791B1

公开(公告)日：2015-10-27

申请号：US14261301

申请日：2014-04-24

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Arnaud Jean-Louis Charton ,  Yuwen Su

IPC: H04M3/00 ,  H04L25/03 ,  H04B3/23 ,  H04M9/08

CPC classification number: H04M3/002 ,  H04B3/23 ,  H04L2025/03687 ,  H04M9/082

Abstract: Features are disclosed for estimating a noise level using a variable step size. An acoustic echo canceller (AEC) may be configured to perform echo cancellation. The acoustic echo canceller may determine an estimated echo using a playback signal. The acoustic echo canceller also may determine an estimated error using the estimated echo and a microphone signal. A variable step size may be determined using the estimated error and the microphone signal. Noise reduction may be performed using the variable step size.

Abstract translation: 公开了使用可变步长估计噪声水平的特征。 声学回声消除器（AEC）可以被配置为执行回声消除。 声学回声消除器可以使用重放信号来确定估计的回波。 声回波消除器还可以使用估计的回波和麦克风信号来确定估计的误差。 可以使用估计误差和麦克风信号来确定可变步长。 可以使用可变步长来执行降噪。

公开(公告)号：US11483646B1

公开(公告)日：2022-10-25

申请号：US15995994

申请日：2018-06-01

Applicant: Amazon Technologies, Inc.

Inventor： Guangdong Pan ,  Philip Ryan Hilmes ,  Robert Ayrapetian

IPC: H04R3/00 ,  H04R1/40

Abstract: Techniques for improving beamforming using filter coefficient values corresponding to virtual microphones are described. A system may define “virtual” microphone positions and determine corresponding filter coefficient values. These filter coefficient values may be applied to input audio data captured by actual physical microphones, enabling the system to improve performance of beamforming and/or to reduce a number of physical microphones without degrading performance. Offline testing and simulations may be performed to identify the best combination of virtual microphones and/or filter coefficient values for a particular look-direction. For example, the simulations may identify that a first filter coefficient corresponding to a first virtual microphone and a first direction will be associated with a first physical microphone and the first direction. During run-time processing, a device may generate beamformed audio data for the first direction by applying the first filter coefficient to input audio data captured by the first physical microphone.

公开(公告)号：US09832569B1

公开(公告)日：2017-11-28

申请号：US15369198

申请日：2016-12-05

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Michael Alan Pogue ,  Kenneth Edgar Hild, II

IPC: H04B3/20 ,  H04R3/00

CPC classification number: H04R3/002 ,  G10L21/0208 ,  G10L2021/02082 ,  H04M9/082 ,  H04R3/02

Abstract: 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.

公开(公告)号：US09589575B1

公开(公告)日：2017-03-07

申请号：US14956992

申请日：2015-12-02

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Philip Ryan Hilmes

IPC: G10L21/0232 ,  H04R3/02 ,  G06F17/14 ,  G10L21/0208

CPC classification number: H04R3/02 ,  G10L21/00 ,  G10L25/18 ,  G10L2021/02082 ,  H04R3/005 ,  H04R2420/07

Abstract: An echo cancellation system that detects and compensates for differences in sample rates between the echo cancellation system and a set of wireless speakers based on a frequency-domain analysis. The system generates Fourier transforms for a microphone signal and a reference signal and determines a series of angles for individual frames. For each tone in the Fourier transforms, the system determines the angles and uses linear regression to determine an individual frequency offset associated with the tone. Using the individual frequency offsets associated with the tones, the system uses linear regression to determine an overall frequency offset between the audio sent to the speakers and the audio received from a microphone. Based on the overall frequency offset, samples of the audio are added or dropped when echo cancellation is performed, compensating for the frequency offset.

Abstract translation: 一种回波消除系统，其基于频域分析来检测和补偿回波消除系统和一组无线扬声器之间采样率的差异。 该系统产生用于麦克风信号和参考信号的傅里叶变换，并确定各个帧的一系列角度。 对于傅里叶变换中的每个音调，系统确定角度并使用线性回归来确定与音调相关联的单个频率偏移。 使用与音调相关联的各个频率偏移，系统使用线性回归来确定发送到扬声器的音频和从麦克风接收的音频之间的总频率偏移。 基于总体频率偏移，当执行回波消除时，音频的样本被添加或丢弃，补偿频率偏移。

公开(公告)号：US09516410B1

公开(公告)日：2016-12-06

申请号：US14753332

申请日：2015-06-29

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Philip Ryan Hilmes

IPC: H04B3/20 ,  H04R3/00

CPC classification number: H04R3/02 ,  H04R1/1008 ,  H04R1/1083 ,  H04R2420/07 ,  H04S3/00

Abstract: An echo cancellation system that detects and compensations for differences in sample rates between the echo cancellation system and a set of wireless speakers based on a frequency-domain analysis of estimated impulse response coefficients. The system tracks the real and imaginary number components of the coefficients, and determines a “rotation” of the coefficients over time caused by a frequency offset between the audio sent to the speakers and the audio received from a microphone. Based on the rotation, samples of the audio are added or dropped when echo cancellation is performed, compensating for the frequency offset.

Abstract translation: 一种回波消除系统，其基于估计的脉冲响应系数的频域分析来检测和补偿回波消除系统和一组无线扬声器之间的采样率差异。 该系统跟踪系数的实数和虚数分量，并且确定由发送到扬声器的音频和从麦克风接收的音频之间的频率偏移引起的随时间的系数的“旋转”。 基于旋转，当执行回波消除时，音频的样本被添加或丢弃，补偿频率偏移。

公开(公告)号：US09036816B1

公开(公告)日：2015-05-19

申请号：US14210154

申请日：2014-03-13

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Yuwen Su ,  Arnaud Jean-Louis Charton

IPC: H04M9/08 ,  H04M1/20 ,  H04B3/23

CPC classification number: H04M1/20 ,  H04B3/232 ,  H04M9/082

Abstract: A acoustic echo canceller (AEC) system may be configured to perform echo cancellation in the frequency domain. Features are disclosed for determining an estimated echo in the frequency domain using adaptive filters. An adaptive filter corresponding to a frequency bin can comprise a plurality of filter taps. Additional features are disclosed for updating the adaptive filter. In addition, a frequency-bin dependent step size controller may be used to control a step size used in updating the adaptive filters. Features are disclosed for determining the frequency-bin dependent step size.

Abstract translation: 声学回声消除器（AEC）系统可以被配置为在频域中执行回声消除。 公开了用于使用自适应滤波器来确定频域中的估计回波的特征。 对应于频率仓的自适应滤波器可以包括多个滤波器抽头。 公开了用于更新自适应滤波器的附加特征。 此外，可以使用频率槽相关步长控制器来控制用于更新自适应滤波器的步长。 公开了用于确定频率依赖步长的特征。

公开(公告)号：US09997151B1

公开(公告)日：2018-06-12

申请号：US15001840

申请日：2016-01-20

Applicant: Amazon Technologies, Inc.

Inventor： Robert Ayrapetian ,  Philip Ryan Hilmes ,  Yuwen Su

IPC: H04R3/02 ,  G10K11/178

CPC classification number: G10K11/178 ,  G10K2210/3012 ,  G10K2210/30232 ,  G10K2210/3025 ,  G10K2210/3229 ,  G10L21/0208 ,  G10L2021/02082

Abstract: An acoustic echo cancellation (AEC) system that detects and compensates for differences in delay times between the AEC system and a set of wireless speakers. The filter coefficients used for AEC are adjusted based on the determined delay time to correct for frequency domain signal rotation.