# US 11,308,959 B2 · Dynamic adjustment of wake word acceptance tolerance thresholds in voice-controlled devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,308,959 B2 - Document ID: US11308959B2 - Status: Granted - Kind: B2 - Application number: 16/787,993 - Filed: 2020-02-11 - Published: 2021-08-12 - Granted: 2022-04-19 - Earliest claimed: 2020-02-11 - Assignees: Spotify AB - Applicants: Spotify AB - Inventors: Daniel Bromand; Joseph Cauteruccio; Sven Erland Fredrik Lewin - Web page: https://patentgrep.com/patent/US11308959B2 ## CPC - G10L 15/22: Procedures used during a speech recognition process, e.g. man-machine dialogue - G10L 15/08: Speech classification or search - G10L 15/30: Distributed recognition, e.g. in client-server systems, for mobile phones or network applications - G10L 21/0232: Processing in the frequency domain - H04R 1/406: {microphones} - H04R 3/005: {for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407)} - H04R 5/027: Spatial or constructional arrangements of microphones, e.g. in dummy heads - G10L 21/0208: Noise filtering - G10L 2015/088: {Word spotting} - G10L 2015/223: {Execution procedure of a spoken command} - G10L 2021/02082: {the noise being echo, reverberation of the speech} - G10L 2021/02165: {Two microphones, one receiving mainly the noise signal and the other one mainly the speech signal} - G10L 2021/02166: {Microphone arrays; Beamforming} - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract Systems and methods are provided for detecting wake words. An electronic device detects an audio signal; identifies two spatial zones as first and second sources of audio associated with the audio signal; processes the audio signal at two wake word detection engines, where each detection engine is associated with a respective spatial zone; determines, based on the processing at the wake word detection engines, whether the audio signal represents a wake word for the electronic device; and in accordance with a determination that the audio signal does represent a wake word, adjusts a wake word detection threshold for at least one of the wake word detection engines. ## Claims ### Claim 1 A method, comprising: at an electronic voice-controlled speaker device including an audio front end system having a microphone array, one or more processors, and memory storing instructions for execution by the one or more processors: detecting, from the microphone array, an audio signal in an environment proximate to the audio front end system; identifying a first spatial zone of a plurality of spatial zones in the environment as a first source of audio associated with the audio signal; assigning a first wake word detection engine of a plurality of wake word detection engines to the first spatial zone in accordance with the identifying of the first spatial zone as a first source of audio; identifying a second spatial zone of the plurality of spatial zones in the environment as a second source of audio associated with the audio signal, wherein the second spatial zone is different from the first spatial zone; assigning a second wake word detection engine of the plurality of wake word detection engines to the second spatial zone in accordance with the identifying of the second spatial zone as a second source of audio; processing the audio signal at the first wake word detection engine assigned to the first spatial zone; processing the audio signal at the second wake word detection engine assigned to the second spatial zone; determining, based on the processing at the first wake word detection engine and based on the processing at the second wake word detection engine, whether the audio signal represents a wake word for the electronic voice-controlled speaker device; and in accordance with a determination that the audio signal represents a wake word for the electronic voice-controlled speaker device, adjusting a wake word detection threshold for at least one of the first wake word detection engine and the second wake word detection engine. ### Claim 2 (depends on 1) The method of claim 1, wherein: identifying the first spatial zone comprises aligning first component sound waves of the audio signal detected from the first source of audio; identifying the second spatial zone comprises aligning second component sound waves of the audio signal detected from the second source of audio; processing the audio signal at the first wake word detection engine comprises performing a wake word detection process on the aligned first component sound waves; and processing the audio signal at the second wake word detection engine comprises performing a wake word detection process on the aligned second component sound waves. ### Claim 3 (depends on 2) The method of claim 2, wherein: determining whether the audio signal represents a wake word for the electronic voice-controlled speaker device comprises applying a noise cancelation process at the first wake word detection engine based on the processing of the audio signal at the second wake word detection engine. ### Claim 4 (depends on 2) The method of claim 2, wherein: adjusting the wake word detection threshold comprises adjusting a wake word detection threshold associated with the second wake word detection engine based on a determination by the first wake word detection engine that the audio signal represents a wake word for the electronic voice-controlled speaker device. ### Claim 5 (depends on 4) The method of claim 4, wherein: adjusting the wake word detection threshold associated with the second wake word detection engine comprises increasing the wake word detection threshold for the second wake word detection engine on a spectrum of strictness. ### Claim 6 (depends on 1) The method of claim 1, further comprising: identifying a third spatial zone of the plurality of spatial zones in the environment as a third source of audio associated with the audio signal, wherein the third spatial zone is different from the first and second spatial zones; causing a third wake word detection engine to be made available for processing the audio signal; and assigning the third wake word detection engine to the third spatial zone. ### Claim 7 (depends on 6) The method of claim 6, wherein causing the third wake word detection engine to be made available for processing the audio signal comprises: dynamically adjusting how many wake word detection engines are available for processing the audio signal. ### Claim 8 (depends on 1) The method of claim 1, wherein: the wake word detection threshold is used in subsequent processing of audio signals at the first wake word detection engine, and corresponds with a probability that the audio signal represents a wake word. ### Claim 9 (depends on 1) The method of claim 1, wherein adjusting the wake word detection threshold comprises adjusting the wake word detection threshold based on a spatial model of the environment representing locations and probabilities of wake word source zones. ### Claim 10 (depends on 9) The method of claim 9, wherein the spatial model is based on a Bayesian inference analysis using a probability distribution to determine the probability of detecting a valid wake word. ### Claim 11 (depends on 1) The method of claim 1, further comprising: configuring the audio front end system to detect subsequent audio signals from a direction associated with a spatial zone corresponding with the determination that the audio signal represents a wake word for the electronic voice-controlled speaker device; and maintaining the audio front end configuration until the electronic voice-controlled speaker device receives an end of speech feedback signal from a distinct voice service process. ### Claim 12 An electronic voice-controlled speaker device including an audio front end system having a microphone array, one or more processors, and memory storing one or more programs to be executed by the one or more processors, the one or more programs including instructions for: detecting, from the microphone array, an audio signal in an environment proximate to the audio front end system; identifying a first spatial zone of a plurality of spatial zones in the environment as a first source of audio associated with the audio signal; assigning a first wake word detection engine of a plurality of wake word detection engines to the first spatial zone in accordance with the identifying of the first spatial zone as a first source of audio; identifying a second spatial zone of the plurality of spatial zones in the environment as a second source of audio associated with the audio signal, wherein the second spatial zone is different from the first spatial zone; assigning a second wake word detection engine of the plurality of wake word detection engines to the second spatial zone in accordance with the identifying of the second spatial zone as a second source of audio; processing the audio signal at the first wake word detection engine assigned to the first spatial zone; processing the audio signal at the second wake word detection engine assigned to the second spatial zone; determining, based on the processing at the first wake word detection engine and based on the processing at the second wake word detection engine, whether the audio signal represents a wake word for the electronic voice-controlled speaker device; and in accordance with a determination that the audio signal represents a wake word for the electronic voice-controlled speaker device, adjusting a wake word detection threshold for at least one of the first wake word detection engine and the second wake word detection engine. ### Claim 13 (depends on 12) The electronic voice-controlled speaker device of claim 12, wherein the instructions for: identifying the first spatial zone include instructions for aligning first component sound waves of the audio signal detected from the first source of audio; identifying the second spatial zone include instructions for aligning second component sound waves of the audio signal detected from the second source of audio; processing the audio signal at the first wake word detection engine include instructions for performing a wake word detection process on the aligned first component sound waves; and processing the audio signal at the second wake word detection engine include instructions for performing a wake word detection process on the aligned second component sound waves. ### Claim 14 (depends on 13) The electronic voice-controlled speaker device of claim 13, wherein the instructions for: determining whether the audio signal represents a wake word for the electronic voice-controlled speaker device include instructions for applying a noise cancelation process at the first wake word detection engine based on the processing of the audio signal at the second wake word detection engine. ### Claim 15 (depends on 13) The electronic voice-controlled speaker device of claim 13, wherein the instructions for: adjusting the wake word detection threshold include instructions for adjusting a wake word detection threshold associated with the second wake word detection engine based on a determination by the first wake word detection engine that the audio signal represents a wake word for the electronic voice-controlled speaker device. ### Claim 16 (depends on 15) The electronic voice-controlled speaker device of claim 15, wherein the instructions for: adjusting the wake word detection threshold associated with the second wake word detection engine include instructions for increasing the wake word detection threshold for the second wake word detection engine on a spectrum of strictness. ### Claim 17 A non-transitory computer readable storage medium storing one or more programs configured for execution by an electronic voice-controlled speaker device including an audio front end system having a microphone array, the one or more programs including instructions for: detecting, from the microphone array, an audio signal in an environment proximate to the audio front end system; identifying a first spatial zone of a plurality of spatial zones in the environment as a first source of audio associated with the audio signal; assigning a first wake word detection engine of a plurality of wake word detection engines to the first spatial zone in accordance with the identifying of the first spatial zone as a first source of audio; identifying a second spatial zone of the plurality of spatial zones in the environment as a second source of audio associated with the audio signal, wherein the second spatial zone is different from the first spatial zone; assigning a second wake word detection engine of the plurality of wake word detection engines to the second spatial zone in accordance with the identifying of the second spatial zone as a second source of audio; processing the audio signal at the first wake word detection engine; processing the audio signal at the second wake word detection engine; determining, based on the processing at the first wake word detection engine and based on the processing at the second wake word detection engine, whether the audio signal represents a wake word for the electronic voice-controlled speaker device; and in accordance with a determination that the audio signal represents a wake word for the electronic voice-controlled speaker device, adjusting a wake word detection threshold for at least one of the first wake word detection engine and the second wake word detection engine. ### Claim 18 (depends on 17) The non-transitory computer readable storage medium of claim 17, wherein the instructions for: identifying the first spatial zone include instructions for aligning first component sound waves of the audio signal detected from the first source of audio; identifying the second spatial zone include instructions for aligning second component sound waves of the audio signal detected from the second source of audio; processing the audio signal at the first wake word detection engine include instructions for performing a wake word detection process on the aligned first component sound waves; and processing the audio signal at the second wake word detection engine include instructions for performing a wake word detection process on the aligned second component sound waves. ### Claim 19 (depends on 18) The non-transitory computer readable storage medium of claim 18, wherein the instructions for: determining whether the audio signal represents a wake word for the electronic voice-controlled speaker device include instructions for applying a noise cancelation process at the first wake word detection engine based on the processing of the audio signal at the second wake word detection engine. ### Claim 20 (depends on 18) The non-transitory computer readable storage medium of claim 18, wherein the instructions for: adjusting the wake word detection threshold include instructions for adjusting a wake word detection threshold associated with the second wake word detection engine based on a determination by the first wake word detection engine that the audio signal represents a wake word for the electronic voice-controlled speaker device.