Sonos, Inc.

Patrick Kevin McPherson

Shao-Fu Shih

Klaus Hartung

Aurelio Rafael Ramos

Connor Kristopher Smith

Kurt Thomas Soto

Charles Conor Sleith

Wenyu Jin

Adib Mehrabi

Roberto Maria Dizon

Systems and methods for determining and adapting to changes in microphone performance of playback devices are disclosed herein. In one example, an audio input is received at an array of individual microphones of a network microphone device. Output microphone signals are generated from each of the individual microphones based on the audio input. The output microphone signals are analyzed to detect a trigger event. After detecting the trigger event, the output microphone signals are compared to detect aberrant behavior of one or more of the microphones. Optionally, corrective actions can be taken or suggested based on the detection of aberrant behavior of one or more microphones.

Determining and adapting to changes in microphone performance of playback devices

Example techniques relate to audio playback device calibration. Example playback devices described herein may utilize one or more techniques for calibration, which may be implemented as various calibration procedures. In some implementations, the example media playback system may support multiple types of calibration, perhaps with different calibration procedures being used for different types of playback devices (e.g., with different capabilities) or in different situations (e.g., with or without user involvement).

Calibration of audio playback devices

Example techniques described herein relate to calibration of a playback device. Using example techniques, a playback device may self-calibrate by measuring a self-response and using a transfer function to map the self-response to an estimate of a room response. The playback device may determine calibration settings to at least partially offset acoustic characteristics of an environment surrounding the playback device as represented in the estimated room response. The transfer function may be derived from a principal component analysis of a dataset including multiple room responses, perhaps as measured during a multi-point calibration process of the playback device in various environments and conditions.

Playback device self-calibration using PCA-based room response estimation

An audio playback device comprises a microphone, a speaker, and a processor. The processor is arranged to output by the speaker first audio content and receive by the microphone an indication of the first audio content. A first acoustic response of a room in which the audio playback device is located is determined based on the received indication of first audio content. A mapping is applied to the first acoustic response to determine a second acoustic response. The second acoustic response is indicative of an approximated acoustic response of the room at a spatial location different from a spatial location of the microphone. The second audio content output by the speaker is adjusted based on the second response.

Examples described herein relate to calibration of audio playback devices in a media playback system using inputs derived from a multi-channel adaptive filter of an acoustic echo canceller. Example playback devices described herein may utilize one or more techniques for calibration, which may be implemented as various calibration procedures. In some implementations, an example playback device may implement a self-calibration procedure, which involves the playback device calibrating (or re-calibrating) itself during operation. Yet further, the playback device may estimate acoustic impulse responses from a multi-channel adaptive filter of an acoustic echo canceller to use as inputs to the self-calibration procedure.

Multi-channel AEC system identification for self-calibration

An example playback device is configured to receive a first stream of audio comprising source audio content to be played back by the playback device and record, via one or more microphones of the playback device, an audio signal output by the playback device based on the playback device playing the source audio content. The playback device is also configured to determine a transfer function between a frequency-domain representation of the first stream of audio and a frequency-domain representation of the recorded audio signal, and then determine an estimated frequency response of the playback device based on a difference between (i) the transfer function and (ii) a self-response of the playback device, where the self-response of the playback device is stored in a memory of the playback device. Based on the estimated frequency response, the playback device is configured to determine an acoustic calibration adjustment and implement the acoustic calibration adjustment.

Calibration of a playback device based on an estimated frequency response

Disclosed herein are example techniques to facilitate calibrating a portable playback device. An example implementation involves determining that a playback device is to perform an equalization calibration of the playback device and initiating the equalization calibration. Initiating the equalization calibration involves (i) outputting audio content, (ii) capturing audio data representing reflections of the audio content within an area in which the playback device is located, (iii) determining an acoustic response of the area in which the playback device is located, (iv) selecting a stored acoustic response from the acoustic response database that is most similar to the determined acoustic response of the area in which the playback device is located, and (v) applying to the audio content, via the playback device, a set of stored audio calibration settings associated with the selected stored acoustic area response.

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Somerville, MA, United States of America

Patrick Kevin McPherson