Amazon Technologies, Inc.

Aditya Sharadchandra Joshi

Carlo Murgia

Michael Thomas Peterson

Dibyendu Nandy

Zhouhui Miao

Devices and techniques are generally described for wake word suppression using variable step size of an acoustic echo cancellation (AEC) unit. A reference signal representing an audio stream may be sent to an acoustic echo cancellation (AEC) unit. A microphone may receive an input audio signal and send the input audio signal to the AEC unit. The AEC unit may determine a first set of variable step size (Vss) values over the first time period. Vss values may define a rate at which the AEC unit determines a transfer function between the reference signal and the first input audio signal. A wake-word may be detected during the first time period. A determination may be made that the wake-word is part of the audio output by the loudspeaker based at least in part on the first set of Vss values.

Device control using variable step size of acoustic echo cancellation

A system configured to perform audio processing with adaptive multi-stage output gains. For example, an Audio Front End (AFE) component may generate a first output using a fixed gain value in order to improve device arbitration and a second output using an adaptive gain value in order to improve wakeword detection. A wakeword engine may process the second output to determine that a wakeword is present along with start/end times of the wakeword. The AFE component can use the start/end times to determine an amount of wakeword energy represented in the first output, which is sent to a remote device for device arbitration. The AFE component can also use the start/end times to determine an amount of wakeword energy represented in the second output, which can be used to determine the adaptive gain value that is unique to the device.

Adaptive multi-stage output gain

A system configured to perform self-trigger prevention to avoid a device waking itself up when a wakeword is output by the device's own output audio. For example, during active playback the device may perform double-talk detection and suppress wakewords or other device-directed utterances when near-end speech is not present. To detect whether near-end speech is present, an Audio Front End (AFE) of the device may perform echo cancellation and generate correlation data indicating an amount of correlation between an output of the echo canceller and an estimated reference signal. When the correlation is high in certain frequency ranges, near-end speech is not present and the device may suppress the utterance. When the correlation is low, indicating that near-end speech could be present, the device does not suppress the utterance and sends the utterance to a remote system for speech processing.

Self-trigger prevention

Techniques for encoding audio data with metadata are described. In an example, a device receives audio data corresponding to audio detected by a microphone and receives metadata associated with the audio. The device generates encoded data based at least in part on encoding the audio data with the metadata. The encoding involves replacing a portion of the audio data with the metadata, such that the encoded data includes the metadata and a remaining portion of the audio data. The device sends the encoded data to an audio processing application.

Encoding audio metadata in an audio frame

Techniques for improving the power consumption of a device without impacting or with minimal impact to operations of the device are described. In an example, the device includes a processor. The device receives, while the processor is operating in a first power mode, first input data corresponding to first audio detected by a microphone. Based at least in part on the first input data, the device detects a sound event or ambient noise. Based at least in part on a detection of the ambient noise only, the device causes processor to operate in a second power mode in which the processor consumes less power than in the first power mode.

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Sunnyvale, CA, United States of America

Aditya Sharadchandra Joshi