CASCADED ADAPTIVE INTERFERENCE CANCELLATION ALGORITHMS

    公开(公告)号:US20220109929A1

    公开(公告)日:2022-04-07

    申请号:US17553976

    申请日:2021-12-17

    摘要: Techniques for improving adaptive interference cancellation (AIC) using cascaded AIC algorithms are described. To improve an accuracy of detecting speech, a device may perform a first stage of AIC to generate isolated audio data and may generate speech mask data indicating time windows when speech is detected in the isolated audio data. Based on the speech mask data, the device may perform second AIC to generate output audio data, with adaptation of the adaptive filter enabled when the speech is not detected and disabled when the speech is detected. Thus, the first AIC improves the accuracy with which the device detects that speech is present and the second AIC reduces distortion in the output audio data by not updating filter coefficient values when the speech is present. The first AIC may use playback audio data, microphone audio data or beamformed audio data as reference signals.

    Dereverberation and noise reduction

    公开(公告)号:US11386911B1

    公开(公告)日:2022-07-12

    申请号:US16915037

    申请日:2020-06-29

    摘要: 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.

    Voice detection using ear-based devices

    公开(公告)号:US10972834B1

    公开(公告)日:2021-04-06

    申请号:US16787580

    申请日:2020-02-11

    IPC分类号: H04R3/00 H04R1/10

    摘要: This disclosure describes techniques for detecting voice commands from a user of an ear-based device. The ear-based device may include an in-ear facing microphone to capture sound emitted in an ear of the user, and an exterior facing microphone to capture sound emitted in an exterior environment of the user. The in-ear microphone may generate an inner audio signal representing the sound emitted in the ear, and the exterior microphone may generate an outer audio signal representing sound from the exterior environment. The ear-based device may compute a ratio of a power of the inner audio signal to the outer audio signal and may compare this ratio to a threshold. If the ratio is larger than the threshold, the ear-based device may detect the voice of the user. Further, the ear-based device may set a value of the threshold based on a level of acoustic seal of the ear-based device.

    Direction finding of sound sources

    公开(公告)号:US11950062B1

    公开(公告)日:2024-04-02

    申请号:US17709563

    申请日:2022-03-31

    IPC分类号: H04R3/00 G10L25/21 H04R1/40

    CPC分类号: H04R3/005 G10L25/21 H04R1/406

    摘要: A system configured to improve sound source localization (SSL) processing by reducing a number of direction vectors and grouping the direction vectors into direction cells is provided. The system performs clustering to generate a smaller set of direction vectors included in a delay-direction codebook, reducing a size of the codebook to the number of unique delay vectors. In addition, the system groups the direction vectors into direction cells having a regular structure (e.g., predetermined uniformity and/or symmetry), which simplifies SSL processing and results in a substantial reduction in computational cost. The system may also select between multiple codebooks and/or dynamically adjust the codebook to compensate for changes to the microphone array. For example, a device with a microphone array fixed to a display that can tilt may adjust the codebook based on a tilt angle of the display to improve accuracy.

    Microphone occlusion detection
    9.
    发明授权

    公开(公告)号:US11528571B1

    公开(公告)日:2022-12-13

    申请号:US17150599

    申请日:2021-01-15

    摘要: A system configured to perform microphone occlusion event detection. When a device detects a microphone occlusion event, the device will modify audio processing performed prior to speech processing, such as by disabling spatial processing and only processing audio data from a single microphone. The device detects the microphone occlusion event by determining inter-level difference (ILD) values between two microphone signals and using the ILD values as input features to a classifier. For example, when a far-end reference signal is inactive, the classifier may process a first ILD value within a high frequency band. However, when the far-end reference signal is active, the classifier may process the first ILD value and a second ILD value within a low frequency band.

    Voice detection using hearable devices

    公开(公告)号:US11290802B1

    公开(公告)日:2022-03-29

    申请号:US15883888

    申请日:2018-01-30

    摘要: Techniques for detecting a voice command from a user of a hearable device. The hearable device may include an in-ear facing microphone to capture sound emitted from an ear of the user, and an exterior facing microphone to capture sound emitted from an exterior environment of the user. The in-ear microphone may generate an in-ear audio signal representing the sound emitted from the ear, and the exterior microphone may generate an exterior audio signal representing sound from the exterior environment. The hearable device may include components to determine correlations or similarities between the in-ear audio signal and exterior audio signal, which indicate that the audio signals represent sound emitted from the user. Further, the components may perform voice activity detection to determine that the sound emitted from the user is a voice command, and proceed to perform further voice-processing techniques.