Mitigating effects of electronic audio sources in expression detection
First Claim
1. A system comprising:
- a microphone array configured to produce microphone audio signals;
an audio beamformer configured to process the microphone audio signals to produce directional audio signals, wherein a first directional audio signal of the directional audio signals corresponds to a first direction with respect to the microphone array and wherein a second directional audio signal of the directional audio signals corresponds to a second direction with respect to the microphone array, wherein the first directional audio signal and the second directional audio signal emphasize sound from the first direction and the second direction, respectively;
a speech activity detector configured to analyze one or more frequency characteristics of the first directional audio signal and the second directional audio signal to determine a first level of speech presence and a second level of speech presence occurring in the first direction and the second direction, respectively, over time;
a source detector configured to analyze the first level of speech presence and the second level of speech presence occurring over a past time period to determine that an electronic source of sound is located in the first direction or the second direction; and
an expression detector configured to perform actions comprising;
identifying the first direction where a first occurring level of speech presence is a highest level of speech presence;
determining that the first direction corresponds to a direction in which the electronic source of sound is located;
identifying the second direction where a second occurring level of speech presence is a second highest level of speech presence;
analyzing the first directional audio signal corresponding to the first direction to produce a first score indicating a first likelihood that a trigger expression is represented in the first directional audio signal;
analyzing the second directional audio signal corresponding to the second direction to produce a second score indicating a second likelihood that the trigger expression is represented in the second directional audio signal;
comparing the first score to a first threshold;
comparing the second score to a second threshold, wherein the second threshold is less than the first threshold;
determining that (i) the first score is greater than the first threshold or (ii) the second score is greater than the second threshold;
concluding that the trigger expression has been uttered; and
performing speech recognition on subsequent speech, based at least in part on the trigger expression.
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Abstract
In a speech-based system, a wake word or other trigger expression is used to preface user speech that is intended as a command. The system receives multiple directional audio signals, each of which emphasizes sound from a different direction. The signals are monitored and analyzed to detect the directions of interfering audio sources such as televisions or other types of electronic audio players. One of the directional signals having the strongest presence of speech is selected to be monitored for the trigger expression. If the directional signal corresponds to the direction of an interfering audio source, a more strict standard is used to detect the trigger expression. In addition, the directional audio signal having the second strongest presence of speech may also be monitored to detect the trigger expression.
67 Citations
23 Claims
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1. A system comprising:
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a microphone array configured to produce microphone audio signals; an audio beamformer configured to process the microphone audio signals to produce directional audio signals, wherein a first directional audio signal of the directional audio signals corresponds to a first direction with respect to the microphone array and wherein a second directional audio signal of the directional audio signals corresponds to a second direction with respect to the microphone array, wherein the first directional audio signal and the second directional audio signal emphasize sound from the first direction and the second direction, respectively; a speech activity detector configured to analyze one or more frequency characteristics of the first directional audio signal and the second directional audio signal to determine a first level of speech presence and a second level of speech presence occurring in the first direction and the second direction, respectively, over time; a source detector configured to analyze the first level of speech presence and the second level of speech presence occurring over a past time period to determine that an electronic source of sound is located in the first direction or the second direction; and an expression detector configured to perform actions comprising; identifying the first direction where a first occurring level of speech presence is a highest level of speech presence; determining that the first direction corresponds to a direction in which the electronic source of sound is located; identifying the second direction where a second occurring level of speech presence is a second highest level of speech presence; analyzing the first directional audio signal corresponding to the first direction to produce a first score indicating a first likelihood that a trigger expression is represented in the first directional audio signal; analyzing the second directional audio signal corresponding to the second direction to produce a second score indicating a second likelihood that the trigger expression is represented in the second directional audio signal; comparing the first score to a first threshold; comparing the second score to a second threshold, wherein the second threshold is less than the first threshold; determining that (i) the first score is greater than the first threshold or (ii) the second score is greater than the second threshold; concluding that the trigger expression has been uttered; and performing speech recognition on subsequent speech, based at least in part on the trigger expression. - View Dependent Claims (2, 3, 4, 5)
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6. A processor-implemented method, comprising:
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receiving, from one or more microphones, a plurality of audio signals, wherein the plurality of audio signals are processed by an audio beamformer to produce directional audio signals, wherein a first audio signal of the directional audio signals corresponds to a first direction with respect to the one or more microphones and wherein a second audio signal of the directional audio signals corresponds to a second direction with respect to the one or more microphones, wherein the first audio signal and the second audio signal emphasize sound from the first direction and the second direction, respectively; identifying the first direction as an identified direction in which a non-human sound source is located; analyzing the first audio signal to identify a representation of speech; determining that the first audio signal corresponds to the identified direction in which the non-human sound source is located; selecting a first standard to analyze the first audio signal based at least in part on the first audio signal corresponding to the identified direction of the non-human sound source; analyzing the first audio signal using the first standard to detect an utterance of a trigger expression; analyzing the second audio signal using a second standard to detect the utterance of the trigger expression, wherein the first standard includes (i) a first threshold that is greater than a second threshold associated with the second standard or (ii) a first detection algorithm that is different than a second detection algorithm associated with the second standard; and receiving, from the one or more microphones, a third audio signal including subsequent speech for performing subsequent speech recognition, based at least in part on the utterance of the trigger expression. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 23)
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17. A processor-implemented method, comprising:
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receiving, from one or more microphones, a plurality of audio signals, wherein the plurality of audio signals are processed by an audio beamformer to produce directional audio signals, wherein a first audio signal of the directional audio signals corresponds to a first area of an environment with respect to the one or more microphones and wherein a second audio signal of the directional audio signals corresponds to a second area of the environment with respect to the one or more microphones, wherein the first audio signal and the second audio signal emphasize sound from the first area of the environment and the second area of the environment, respectively; determining that the first audio signal represents sound generated by a non-human sound source; selecting a first standard to analyze the first audio signal based at least in part on the first audio signal representing the sound generated by the non-human sound source; analyzing the first audio signal using the first standard to detect an utterance of a trigger expression; analyzing the second audio signal using a second standard to detect the utterance of the trigger expression, wherein the first standard includes (i) a first threshold that is greater than a second threshold associated with the second standard or (ii) a first detection algorithm that is different than a second detection algorithm associated with the second standard; and receiving, from the one or more microphones, subsequent speech for performing subsequent speech recognition, based at least in part on the utterance of the trigger expression. - View Dependent Claims (18, 19, 20, 21, 22)
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Specification