Determining speaker direction using a spherical microphone array
AssigneeAmazon Technologies, Inc.
InventorsJohn Walter McDonough, Jr., Volker Sebastian Leutnant, Sri Venkata Surya Siva Rama Krishna Garimell, Spyridon Matsoukas
Life of this patent
Estimating the term…
Abstract
A system that detects audio including speech using a spherical sensor array estimates a direction of arrival of the speech using a Kalman filter. To improve the estimates of the Kalman filter, the system estimates a noise covariance matrix, representing noise detected by the array. The structure of the noise covariance matrix is determined, using an assumption of spherically isotropic diffuse noise. The intensity of the noise covariance matrix is estimated based on the intensity of audio detected by the array.
Claims18
A computer-implemented method for estimating a direction of arrival of detected speech using a spherical microphone array, the computer-implemented method comprising:
- determining, at a first time, a first noise covariance matrix comprising a plurality of first values, wherein each of the first values describes a covariance between a pair of microphones detecting diffuse noise, wherein the microphones are part of a spherical microphone array;
- detecting, at a second time after the first time, audio using the spherical microphone array;
- determining a signal from the audio using the spherical microphone array, wherein the signal comprises a speech component and a noise component and the signal has a signal intensity calculated from pressure detected by the spherical microphone array;
- estimating, based on the signal intensity, an estimated noise intensity of the noise component;
- multiplying the estimated noise intensity by the plurality of first values to obtain a plurality of second values, wherein a second noise covariance matrix includes the plurality of second values;
- and
- estimating a direction of arrival of the speech component relative to the spherical microphone array using an extended Kalman filter and the second noise covariance matrix.
A system comprising:
- a sensor array comprising a plurality of sensors, the plurality of sensors configured to detect sound;
- at least one processor;
- and
- a memory including instruction operable to be executed by the at least one processor to perform a set of actions comprising:
- determining an audio signal using the sensor array, the audio signal having a signal intensity and comprising a speech component and a noise component;
- estimating, based on the signal intensity, an estimated noise intensity of the noise component;
- determining a first noise covariance matrix comprising a plurality of first values, wherein each of the first values describes a covariance between a pair of sensors of the sensor array;
- multiplying the estimated noise intensity by the first noise covariance matrix to obtain a second noise covariance matrix;
- and
- estimating a direction of arrival of the speech component relative to the sensor array using a Kalman filter and the first noise covariance matrix and the second noise covariance matrix.
A computer-implemented method, comprising:
- determining an audio signal using a sensor array, the sensor array comprising a plurality of sensors to detect sound and the audio signal having a signal intensity and comprising a speech component and a noise component;
- estimating, based on the signal intensity, an estimated noise intensity of the noise component;
- determining a first noise covariance matrix comprising a plurality of first values, wherein each of the first values describes a covariance between a pair of sensors of the sensor array;
- multiplying the estimated noise intensity by the first noise covariance matrix to obtain a second noise covariance matrix;
- and
- estimating a direction of arrival of the speech component relative to the sensor array using a Kalman filter and the first noise covariance matrix and the second noise covariance matrix.
Dependencies are inferred from the claim text.