# US 10,455,347 B2 · Playback based on number of listeners > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,455,347 B2 - Document ID: US10455347B2 - Status: Granted - Kind: B2 - Application number: 15/235,598 - Filed: 2016-08-12 - Published: 2016-12-01 - Granted: 2019-10-22 - Earliest claimed: 2011-12-29 - Assignees: Sonos, Inc. - Applicants: Sonos, Inc. - Inventors: Jonathon Reilly; Niels Van Erven - Web page: https://patentgrep.com/patent/US10455347B2 ## CPC - H04S 7/303: {Tracking of listener position or orientation} - G01S 3/023: {Monitoring or calibrating} - G01S 3/80: using ultrasonic, sonic or infrasonic waves - G06F 3/165: {Management of the audio stream, e.g. setting of volume, audio stream path} - H04L 41/22: comprising specially adapted graphical user interfaces [GUI] - H04L 67/1042: using topology management mechanisms - H04R 3/04: for correcting frequency response - H04R 27/00: Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; {monitoring or testing arrangements for public address systems H04R29/007}; amplifiers H03F) - H04R 29/001: {for loudspeakers (H04R29/007 takes precedence)} - H04R 29/008: {Visual indication of individual signal levels (visual indication of stereophonic sound image H04S7/40)} - H04S 7/302: {Electronic adaptation of stereophonic sound system to listener position or orientation (H04S7/301 takes precedence)} - H04R 2227/005: Audio distribution systems for home, i.e. multi-room use - H04R 2430/01: Aspects of volume control, not necessarily automatic, in sound systems - H04S 7/301: {Automatic calibration of stereophonic sound system, e.g. with test microphone} - Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection - H04S: STEREOPHONIC SYSTEMS - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - 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) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract Systems, methods, and apparatus to process audio signals based on a number of listeners are disclosed. An example implementation involves a playback device processing, via an audio processing component, an audio signal for playback according to a first audio characteristic. While processing the audio signal for playback according to the first audio characteristic, the playback device detects, via a location component, a number of listeners in a listening area. The playback device determines a second audio characteristic based on the detected number of listeners in the listening area, and after determining the second audio characteristic, processes, via the audio processing component, the audio signal for playback according to the second audio characteristic. ## Claims ### Claim 1 A playback device comprising: one or more speakers; at least one amplifier configured to drive the one or more speakers; one or more location sensors comprising a network interface; one or more processors comprising a digital signal processor; and a housing carrying the one or more speakers, the at least one amplifier, the one or more location sensors, the one or more processors, and data storage for storing instructions that when executed cause the playback device perform functions comprising: detecting, at a first time, a first number of listeners in a listening area, wherein detecting the first number of listeners comprises receiving, via the network interface of the one or more location sensors, network packets transmitted from a mobile device associated with a first listener, wherein the detected first number of listeners is one; determining a first audio characteristic that adjusts a sound field generated by the one or more speakers to create a first sweet spot that includes a location of the first listener relative to the playback device; processing, via the digital signal processor, an audio signal for playback according to the first audio characteristic; playing the processed audio signal via the one or more speakers and the at least one amplifier according to the first audio characteristic; while processing the audio signal for playback according to the first audio characteristic, detecting, at a second time, a second number of listeners in the listening area, wherein detecting the second number of listeners comprises receiving, via the network interface of the one or more location sensors, network packets transmitted from respective mobile devices associated with two or more second listeners, and wherein the detected second number of listeners is greater than one; determining a second audio characteristic that adjusts the sound field generated by the one or more speakers to create a second sweet spot that includes respective locations of the two or more second listeners; after determining the second audio characteristic, processing, via the digital signal processor, the audio signal for playback according to the second audio characteristic; and playing the processed audio signal via the one or more speakers and the at least one amplifier according to the second audio characteristic. ### Claim 2 (depends on 1) The playback device of claim 1, wherein the one or more location sensors further comprise an image capture device, wherein detecting the first number of listeners in the listening area comprises receiving image data representing the listening area at the first time, and wherein detecting the second number of listeners in the listening area comprises receiving image data representing the listening area at the second time. ### Claim 3 (depends on 1) The playback device of claim 1, wherein the one or more location sensors further comprise a microphone, wherein detecting the first number of listeners in the listening area comprises receiving microphone data at the first time, and wherein detecting the second number of listeners in the listening area comprises receiving microphone data at the second time. ### Claim 4 (depends on 1) The playback device of claim 1, wherein the first audio characteristic comprises a first audio filter, and wherein the second audio characteristic comprises a second audio filter. ### Claim 5 (depends on 1) The playback device of claim 1, wherein the first audio characteristic comprises a first volume level, and wherein the second audio characteristic comprises a second volume level. ### Claim 6 (depends on 1) The playback device of claim 1, wherein the playback device is a first playback device, and wherein the functions further comprise: sending, via the network interface, an indication of the second number of listeners in the listening area to a second playback device, thereby causing the second playback device to adjust audio playback from the first audio characteristic to the second audio characteristic based on the detected second number of listeners in the listening area. ### Claim 7 (depends on 1) The playback device of claim 1, wherein determining the second audio characteristic that adjusts the sound field generated by the one or more speakers to create the second sweet spot that includes respective locations of the two or more second listeners comprises determining a particular second audio characteristic that enlarges the first sweet spot to create the second sweet spot that includes respective locations of the two or more second listeners. ### Claim 8 Tangible, non-transitory, computer-readable media having instructions encoded therein, wherein the instructions, when executed by one or more processors, cause a playback device to perform functions comprising: detecting, at a first time, a first number of listeners in a listening area, wherein detecting the first number of listeners comprises receiving, via a network interface of one or more location sensors, network packets transmitted from a mobile device associated with a first listener, wherein the detected first number of listeners is one, and the playback device comprises a housing carrying the one or more location sensors; determining a first audio characteristic that adjusts a sound field generated by one or more speakers of the playback device to create a first sweet spot that includes a location of the first listener relative to the playback device; processing, via a digital signal processor of the playback device, an audio signal for playback according to the first audio characteristic, wherein the housing carries the digital signal processor; while processing the audio signal for playback according to the first audio characteristic, detecting, at a second time, a second number of listeners in the listening area, wherein detecting the second number of listeners comprises receiving, via the network interface of the one or more location sensors, network packets transmitted from respective mobile devices associated with two or more second listeners, and wherein the detected second number of listeners is greater than one; determining a second audio characteristic that adjusts the sound field generated by the one or more speakers to create a second sweet spot that includes respective locations of the two or more second listeners; after determining the second audio characteristic, processing, via the digital signal processor, the audio signal for playback according to the second audio characteristic; and playing the processed audio signal via one or more speakers and at least one amplifier according to the second audio characteristic, wherein the housing carries the one or more speakers and the at least one amplifier. ### Claim 9 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein the one or more location sensors further comprise an image capture device, wherein detecting the first number of listeners in the listening area comprises receiving image data representing the listening area at the first time, and wherein detecting the second number of listeners in the listening area comprises receiving image data representing the listening area at the second time. ### Claim 10 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein the first audio characteristic comprises a first audio filter, and wherein the second audio characteristic comprises a second audio filter. ### Claim 11 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein the first audio characteristic comprises a first volume level, and wherein the second audio characteristic comprises a second volume level. ### Claim 12 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein the playback device is a first playback device, the functions further comprising: sending, via a network interface, an indication of the second number of listeners in the listening area to a second playback device, thereby causing the second playback device to adjust audio playback from the first audio characteristic to the second audio characteristic based on the detected second number of listeners in the listening area. ### Claim 13 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein the one or more location sensors further comprise a microphone, wherein detecting the first number of listeners in the listening area comprises receiving microphone data at the first time, and wherein detecting the second number of listeners in the listening area comprises receiving microphone data at the second time. ### Claim 14 (depends on 8) The tangible, non-transitory, computer-readable media of claim 8, wherein determining the second audio characteristic that adjusts the sound field generated by the one or more speakers to create the second sweet spot that includes respective locations of the two or more second listeners comprises determining a particular second audio characteristic that enlarges the first sweet spot to create the second sweet spot that includes respective locations of the two or more second listeners. ### Claim 15 A method to be performed by a playback device, the method comprising detecting, at a first time, a first number of listeners in a listening area, wherein detecting the first number of listeners comprises receiving, via a network interface of one or more location sensors, network packets transmitted from a mobile device associated with a first listener, wherein the detected first number of listeners is one, and the playback device comprises a housing carrying the one or more location sensors; determining a first audio characteristic that adjusts a sound field generated by one or more speakers to create a first sweet spot that includes a location of the first listener relative to the playback device; processing, via a digital signal processor of the playback device, an audio signal for playback according to the first audio characteristic, wherein the housing carries the digital signal processor; while processing the audio signal for playback according to the first audio characteristic, detecting, at a second time, a second number of listeners in the listening area, wherein detecting the second number of listeners comprises receiving, via the network interface of the one or more location sensors, network packets transmitted from respective mobile devices associated with two or more second listeners, and wherein the detected second number of listeners is greater than one; determining, via the playback device, a second audio characteristic that adjusts the sound field generated by the one or more speakers to create a second sweet spot that includes respective locations of the two or more second listeners; after determining the second audio characteristic, processing, via the digital signal processor of the playback device, the audio signal for playback according to the second audio characteristic; and playing the processed audio signal via one or more speakers and at least one amplifier according to the second audio characteristic, wherein the housing carries the one or more speakers and the at least one amplifier. ### Claim 16 (depends on 15) The method of claim 15, wherein the one or more location sensors further comprise a microphone, wherein detecting the first number of listeners in the listening area comprises receiving microphone data at the first time, and wherein detecting the second number of listeners in the listening area comprises receiving microphone data at the second time. ### Claim 17 (depends on 15) The method of claim 15, wherein the first audio characteristic comprises a first audio filter, and wherein the second audio characteristic comprises a second audio filter. ### Claim 18 (depends on 15) The method of claim 15, wherein the first audio characteristic comprises a first volume level, and wherein the second audio characteristic comprises a second volume level. ### Claim 19 (depends on 15) The method of claim 15, wherein the playback device is a first playback device, and wherein the method further comprises: sending, via the network interface, an indication of the second number of listeners in the listening area to a second playback device, thereby causing the second playback device to adjust audio playback from the first audio characteristic to the second audio characteristic based on the detected second number of listeners in the listening area. ### Claim 20 (depends on 15) The method of claim 15, wherein determining the second audio characteristic that adjusts the sound field generated by the one or more speakers to create the second sweet spot that includes respective locations of the two or more second listeners comprises determining a particular second audio characteristic that enlarges the first sweet spot to create the second sweet spot that includes respective locations of the two or more second listeners.