# US 12,112,738 B2 · Headphone with multiple reference microphones ANC and transparency > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,112,738 B2 - Document ID: US12112738B2 - Status: Granted - Kind: B2 - Application number: 18/450,942 - Filed: 2023-08-16 - Published: 2024-02-08 - Granted: 2024-10-08 - Earliest claimed: 2020-09-16 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Hanchi Chen; Sarthak Khanal; Yang Lu; Vladan Bajic; Esge B. Andersen - Web page: https://patentgrep.com/patent/US12112738B2 ## CPC - G10K 11/17881: {the reference signal being an acoustic signal, e.g. recorded with a microphone} - H04R 1/1083: {Reduction of ambient noise (active noise reduction per se G10K11/175; protective devices for the ear, e.g. providing acoustic protection A61F11/06)} - G10K 11/17827: {Desired external signals, e.g. pass-through audio such as music or speech} - G10K 11/17853: {of the filter} - G10K 11/17854: {the filter being an adaptive filter} - H04R 3/005: {for combining the signals of two or more microphones (specially adapted for hearing aids H04R25/407)} - G10K 2210/1081: Earphones, e.g. for telephones, ear protectors or headsets - G10K 2210/3028: Filtering, e.g. Kalman filters or special analogue or digital filters - H04R 2201/10: Details of earpieces, attachments therefor, earphones or monophonic headphones covered by H04R1/10 but not provided for in any of its subgroups - H04R 2410/01: Noise reduction using microphones having different directional characteristics - H04R 2410/07: Mechanical or electrical reduction of wind noise generated by wind passing a microphone - H04R 2460/01: Hearing devices using active noise cancellation - G10K: SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR - 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 An ear cup housing has several reference microphones, an error microphone and a speaker. A processor drives the speaker for acoustic noise cancellation and transparency, by processing the microphone signals, and performs an oversight process by adjusting the reference microphone signals in response to detecting wind noise events and scratch events. In another aspect, the ear cup housing has an outside face that is joined to an inside face by a perimeter and the reference microphones are on the perimeter. Other aspects are also described and claimed. ## Claims ### Claim 1 A headphone comprising: an ear cup housing having an outside face, an inside face and a perimeter sidewall, the perimeter sidewall is between the outside face and the inside face; at least three external microphones integrated in the ear cup housing that are disposed on the perimeter sidewall of the ear cup housing; an internal microphone and a speaker that are disposed on the inside face of the ear cup housing; and processing circuitry configured to i) drive the speaker for acoustic noise cancellation by processing a) at least one external microphone signal from the at least three external microphones and b) an internal microphone signal from the internal microphone, and ii) drive the speaker for transparency by processing at least one external microphone signal from the at least three external microphones. ### Claim 2 (depends on 1) The headphone of claim 1 wherein the outside face has no sound inlets for microphones, the headphone further comprising a cushion attached to the inside face. ### Claim 3 (depends on 2) The headphone of claim 2 wherein the at least three external microphones are three external microphones. ### Claim 4 (depends on 3) The headphone of claim 3 wherein the three external microphones are positioned at vertices, respectively, of an equilateral triangle. ### Claim 5 (depends on 2) The headphone of claim 2 wherein the at least three external microphones are four external microphones. ### Claim 6 (depends on 5) The headphone of claim 5 wherein the four external microphones are positioned at vertices, respectively, of a square. ### Claim 7 (depends on 1) The headphone of claim 1 wherein for acoustic noise cancellation audio output, the processing circuitry is configured to combine at least two external microphone signals from the at least three external microphones into a single reference input of an anti-noise producing filter. ### Claim 8 (depends on 7) The headphone of claim 7 wherein for transparency audio output, the processing circuitry is configured to combine at least two external microphone signals from the at least three external microphones into a single input of a first transparency filter. ### Claim 9 (depends on 8) The headphone of claim 8 wherein the processing circuitry is configured to adjust one or more of the at least two external microphone signals in response to detecting a wind noise event or a scratch event. ### Claim 10 (depends on 9) The headphone of claim 9 wherein the processing circuitry is detecting the wind noise event by detecting that one or more affected external microphone signals from the at least three external microphones are affected by wind noise, and in response adjusts the one or more affected external microphone signals by attenuating only the one or more affected external microphone signals and no other signals from the at least three external microphones. ### Claim 11 (depends on 8) The headphone of claim 8 further comprising a second transparency filter in cascade with the first transparency filter, wherein the processing circuitry upon detecting that one or more external microphone signals of the at least three external microphones are affected by wind noise adjusts the second transparency filter. ### Claim 12 (depends on 11) The headphone of claim 11 wherein the second transparency filter comprises a low frequency shelf cut filter. ### Claim 13 (depends on 11) The headphone of claim 11 wherein the processing circuitry is detecting the scratch event by detecting an affected one or more external microphone signals from the at least three external microphones are affected by scratch noise and in response adjusts said affected one or more external microphone signals by attenuating the affected one or more external microphone signals and not others. ### Claim 14 (depends on 13) The headphone of claim 13 further comprising a second transparency filter in cascade with the first transparency filter, wherein the processing circuitry upon detecting that one or more external microphone signals from the at least three external microphones are affected by scratch noise adjusts the second transparency filter. ### Claim 15 (depends on 14) The headphone of claim 14 wherein the second transparency filter comprises a notch filter. ### Claim 16 A headset comprising: a first internal microphone, a first speaker, one or more first external microphones, and a first processing circuitry in a housing of a first ear cup; and a second internal microphone, a second speaker, a plurality of second external microphones, and a second processing circuitry in a housing of a second ear cup; the first processing circuitry being configured to produce a) ANC audio output for acoustic noise cancellation based on i) a first external microphone signal from the one or more first external microphones and ii) a first internal microphone signal from the first internal microphone, and b) transparency audio output for transparency based on the first external microphone signal, and the first processing circuitry is further configured to determine a digital filter in the transparency audio output, based on i) the first processing circuitry processing the first internal microphone signal and ii) a result of the second processing circuitry processing a second internal microphone signal from the second internal microphone, wherein the result is transmitted from the second ear cup to the first processing circuitry of the first ear cup. ### Claim 17 (depends on 16) The headset of claim 16 wherein the first processing circuitry determines the digital filter based on processing i) the first internal microphone signal and ii) the result of the second processing circuitry processing the second internal microphone signal, to detect a howl condition. ### Claim 18 (depends on 17) The headset of claim 17 wherein the first processing circuitry determines the digital filter based on comparing spectral content of the first internal microphone signal with spectral content of the second internal microphone signal. ### Claim 19 (depends on 16) The headset of claim 16 wherein the first processing circuitry determines the digital filter based on comparing spectral content of the first internal microphone signal with spectral content of the second internal microphone signal. ### Claim 20 A headphone comprising: an ear cup housing having an outside face, an inside face and a perimeter sidewall, wherein the outside face is spaced apart from the inside face by the perimeter sidewall; at least three external microphones integrated in the ear cup housing that are disposed on the perimeter sidewall of the ear cup housing; an internal microphone and a speaker that are disposed on the inside face of the ear cup housing; and processing circuitry configured to i) drive the speaker for acoustic noise cancellation by processing a) at least one external microphone signal from the at least three external microphones and b) an internal microphone signal from the internal microphone, and ii) drive the speaker for transparency by processing at least one external microphone signal from the at least three external microphones. ### Claim 21 (depends on 20) The headphone of claim 20 wherein the outside face has no sound inlets for microphones, the headphone further comprising a cushion attached to the inside face. ### Claim 22 (depends on 20) The headphone of claim 20 wherein the at least three external microphones are three external microphones. ### Claim 23 (depends on 22) The headphone of claim 22 wherein the three external microphones are positioned at vertices, respectively, of an equilateral triangle. ### Claim 24 (depends on 20) The headphone of claim 20 wherein the at least three external microphones are four external microphones. ### Claim 25 (depends on 24) The headphone of claim 24 wherein the four external microphones are positioned at vertices, respectively, of a square.