# US 12,119,016 B2 · Compressive hear-through in personal acoustic devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,016 B2 - Document ID: US12119016B2 - Status: Granted - Kind: B2 - Application number: 17/381,794 - Filed: 2021-07-21 - Published: 2021-11-11 - Granted: 2024-10-15 - Earliest claimed: 2017-10-30 - Assignees: Bose Corporation - Applicants: Bose Corporation - Inventors: John Allen Rule; Daniel M. Gauger, Jr.; Dale McElhone; Katie Janine Moenkhaus - Web page: https://patentgrep.com/patent/US12119016B2 ## CPC - G10L 21/0232: Processing in the frequency domain - G10K 11/17823: {Reference signals, e.g. ambient acoustic environment} - G10K 11/17833: {by using a self-diagnostic function or a malfunction prevention function, e.g. detecting abnormal output levels} - G10K 11/17835: {using detection of abnormal input signals} - G10K 11/17837: {by retaining part of the ambient acoustic environment, e.g. speech or alarm signals that the user needs to hear} - G10K 11/17885: {additionally using a desired external signal, e.g. pass-through audio such as music or speech} - G10L 25/84: for discriminating voice from noise - 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)} - H04R 3/00: Circuits for transducers (arrangements for producing a reverberation or echo sound G10K15/08; amplifiers H03F) - H04R 5/033: Headphones for stereophonic communication {(details thereof, e.g. relating to batteries, cables or control elements H04R1/10)} - H04R 5/04: Circuit arrangements, {e.g. for selective connection of amplifier inputs/outputs to loudspeakers, for loudspeaker detection, or for adaptation of settings to personal preferences or hearing impairments (combinations of amplifiers H03F3/68; stereophonic systems H04S)} - G10K 11/17827: {Desired external signals, e.g. pass-through audio such as music or speech} - G10K 2210/1081: Earphones, e.g. for telephones, ear protectors or headsets - G10K 2210/3014: Adaptive noise equalizers [ANE], i.e. where part of the unwanted sound is retained - G10K 2210/3016: Control strategies, e.g. energy minimization or intensity measurements - G10K 2210/3039: Nonlinear, e.g. clipping, numerical truncation, thresholding or variable input and output gain - G10K 2210/3056: Variable gain - G10L 25/78: Detection of presence or absence of voice signals (switching of direction of transmission by voice frequency in two-way loud-speaking telephone systems H04M9/10) - H04R 2430/01: Aspects of volume control, not necessarily automatic, in sound systems - H04R 2460/01: Hearing devices using active noise cancellation - G10L: SPEECH ANALYSIS TECHNIQUES OR SPEECH SYNTHESIS; SPEECH RECOGNITION; SPEECH OR VOICE PROCESSING TECHNIQUES; SPEECH OR AUDIO CODING OR DECODING - 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 The technology described in this document can be embodied in a method that includes receiving an input signal representing audio captured by a microphone of an active noise reduction (ANR) headphone, processing, by one or more processing devices, a portion of the input signal to determine a noise level in the input signal, and determining that the noise level satisfies a threshold condition. The method also includes, in response to determining that the noise level satisfies the threshold condition, generating an output signal in which ANR processing on the input signal is controlled in accordance with a target loudness level of the output signal, and driving an acoustic transducer of the ANR headphone using the output signal. ## Claims ### Claim 1 A method comprising: receiving, at one or more processing devices, a first noise-level estimate, the first noise-level estimate being based on a first input signal captured by a first microphone disposed at a first earbud or earcup of an active noise reduction (ANR) headphone; receiving, at the one or more processing devices, a second noise-level estimate, the second noise-level estimate being based on a second input signal captured by a second microphone disposed at a second earbud or earcup of the ANR headphone; estimating an ambient noise level based on the first noise-level estimate and the second noise-level estimate, the estimated ambient noise level being indicative of a loudness of the ambient noise level perceivable by a user; determining that the estimated ambient noise level exceeds a threshold level; and responsive to determining that the estimated ambient noise level exceeds the threshold level, generating, for an ANR signal flow path disposed in each of the first and second earbud or earcup, a gain adjustment signal in accordance with the estimated ambient noise level, such that (i) acoustic outputs from the first and second earbuds or earcups are controlled by the gain adjustment signal and (ii) a degree of ANR processing is controlled by the gain adjustment signal so that an output sound level perceivable by the user increases with an increase in the estimated ambient noise level. ### Claim 2 (depends on 1) The method of claim 1, wherein the threshold level is determined based on a user-input. ### Claim 3 (depends on 1) The method of claim 1, wherein a gain level of the acoustic output from the first earbud or earcup is substantially equal to a gain level of the acoustic output from the second earbud or earcup. ### Claim 4 (depends on 1) The method of claim 1, wherein estimating the ambient noise level based on the first noise-level estimate and the second noise-level estimate comprises determining an average of the first noise-level estimate and the second noise-level estimate. ### Claim 5 (depends on 1) The method of claim 1, wherein each of the first and second noise-level estimates are generated by processing the input signal captured by the corresponding microphone by an A-weighting filter. ### Claim 6 (depends on 1) The method of claim 1, wherein the gain adjustment signal is configured to control a variable gain amplifier (VGA) disposed in the corresponding ANR signal flow path. ### Claim 7 (depends on 6) The method of claim 6, wherein the ANR signal flow path comprises a first signal path that includes the VGA, and a second signal path disposed in parallel to the first signal flow path. ### Claim 8 (depends on 1) The method of claim 1, wherein the ANR signal flow path is disposed in a feedforward signal path disposed between a feedforward microphone and an acoustic transducer of the corresponding earbud or earcup. ### Claim 9 (depends on 1) The method of claim 1, wherein the threshold level is selected from multiple threshold levels, each of which corresponds to a different degree of ANR processing. ### Claim 10 (depends on 1) The method of claim 1, wherein the acoustic output of each of the first and second earbud or earcup is generated in accordance with a compression process executed on the corresponding input signal. ### Claim 11 (depends on 1) The method of claim 1, wherein the gain adjustment signal is generated in accordance with the estimated ambient noise level such that a compression ratio associated with the output sound level perceivable by the user is dependent on the threshold level. ### Claim 12 (depends on 1) The method of claim 1, wherein the gain adjustment signal is generated in accordance with the estimated ambient noise level such that a compression ratio associated with the output sound level perceivable by the user varies with the estimated ambient noise level. ### Claim 13 An apparatus comprising: a noise reduction headphone that includes: a first earbud or earcup, and a second earbud or earcup; a controller comprising one or more processing devices, the controller configured receive a first noise-level estimate, the first noise-level estimate being based on a first input signal captured by a first microphone disposed at the first earbud or earcup, receive a second noise-level estimate, the second noise-level estimate being based on a second input signal captured by a second microphone disposed at a second earbud or earcup, estimate an ambient noise level based on the first noise-level estimate and the second noise-level estimate, the estimated ambient noise level being indicative of a loudness of the ambient noise level perceivable by a user, determine that the estimated ambient noise level exceeds a threshold level, and responsive to determining that the noise level exceeds the threshold level, generate for an ANR signal flow path disposed in each of the first and second earbud or earcup, a gain adjustment signal in accordance with the estimated ambient noise level, such that (i) acoustic outputs from the first and second earbuds or earcups are controlled by the gain adjustment signal and (ii) a degree of ANR processing is controlled by the gain adjustment signal so that an output sound level perceivable by the user increases with an increase in the estimated ambient noise level; and an acoustic transducer in each of the first and second earbud or earcup, the acoustic transducer configured to generate the corresponding acoustic output. ### Claim 14 (depends on 13) The apparatus of claim 13, wherein the noise reduction headphone is an active noise reduction (ANR) headphone. ### Claim 15 (depends on 13) The apparatus of claim 13, wherein the threshold level is determined based on a user-input. ### Claim 16 (depends on 13) The apparatus of claim 13, wherein a gain level of the acoustic output from the first earbud or earcup is substantially equal to a gain level of the acoustic output from the second earbud or earcup. ### Claim 17 (depends on 13) The apparatus of claim 13, wherein estimating the ambient noise level based on the first noise-level estimate and the second noise-level estimate comprises determining an average of the first noise-level estimate and the second noise-level estimate. ### Claim 18 (depends on 13) The apparatus of claim 13, wherein each of the first and second earbud or earcup further comprises an A-weighting filter configured to generate, from the corresponding input signal, the first and second noise-level estimate, respectively. ### Claim 19 (depends on 13) The apparatus of claim 13, wherein the corresponding ANR signal flow path in each of the first and second earbud or earcup comprises a variable gain amplifier (VGA) that is controlled by the gain adjustment signal. ### Claim 20 (depends on 19) The apparatus of claim 19, wherein each of the corresponding ANR signal flow paths comprises a first signal path that includes the VGA, and a second signal path disposed in parallel to the first signal flow path. ### Claim 21 (depends on 13) The apparatus of claim 13, wherein the ANR signal flow path disposed in each of the first and second earbud or earcup is a feedforward signal path. ### Claim 22 One or more machine-readable storage devices having encoded thereon computer readable instructions for causing one or more processing devices to perform operations comprising: receiving a first noise-level estimate, the first noise-level estimate being based on a first input signal captured by a first microphone disposed at a first earbud or earcup of an active noise reduction (ANR) headphone; receiving a second noise-level estimate, the second noise-level estimate being based on a second input signal captured by a second microphone disposed at a second earbud or earcup of the ANR headphone; estimating an ambient noise level based on the first noise-level estimate and the second noise-level estimate, the estimated ambient noise level being indicative of a loudness of the ambient noise level perceivable by a user; determining that the estimated ambient noise level exceeds a threshold level; and responsive to determining that the estimated ambient noise level exceeds the threshold level, generating, for an ANR signal flow path disposed in each of the first and second earbud or earcup, a gain adjustment signal in accordance with the estimated ambient noise level, such that (i) acoustic outputs from the first and second earbuds or earcups are controlled by the gain adjustment signal and (ii) a degree of ANR processing is controlled by the gain adjustment signal so that an output sound level perceivable by the user increases with an increase in the estimated ambient noise level.