# US 11,445,318 B2 · Head-related transfer function determination using cartilage conduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,445,318 B2 - Document ID: US11445318B2 - Status: Granted - Kind: B2 - Application number: 17/180,466 - Filed: 2021-02-19 - Published: 2021-10-07 - Granted: 2022-09-13 - Earliest claimed: 2020-04-01 - Assignees: Meta Platforms Technologies, LLC - Applicants: Meta Platforms Technologies, LLC - Inventors: Morteza Khaleghimeybodi; Vamsi Krishna Ithapu; Antonio John Miller - Web page: https://patentgrep.com/patent/US11445318B2 ## CPC - H04S 7/30: {Control circuits for electronic adaptation of the sound field} - H04R 1/1091: {Details not provided for in groups H04R1/1008 - H04R1/1083} - H04R 25/30: {Monitoring or testing of hearing aids, e.g. functioning, settings, battery power} - H04R 29/001: {for loudspeakers (H04R29/007 takes precedence)} - H04R 2460/13: Hearing devices using bone conduction transducers - H04R 2499/15: Transducers incorporated in visual displaying devices, e.g. televisions, computer displays, laptops - H04S 2420/01: Enhancing the perception of the sound image or of the spatial distribution using head related transfer functions [HRTF's] or equivalents thereof, e.g. interaural time difference [ITD] or interaural level difference [ILD] - H04S: STEREOPHONIC SYSTEMS - 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 Embodiments relate to calibrating head-related transfer functions (HRTFs) for a user of an audio system (e.g., as a component of a headset) using cartilage conducted sounds. A test sound is presented to a user using a transducer (e.g., cartilage conduction) and an audio signal is responsively received via a microphone at an entrance to the user's ear canal. The test sound and audio signal combination may be provided to an audio server where a model is used to determine one or more HRTFs for the user. Information describing the one or more HRTFs is provided to the audio system to be used for providing audio to the user. The audio server may also use a model to determine geometric information describing a pinna of the user based on the combination. In one embodiment, the geometric information is used to determine the one or more HRTFs for the user. ## Claims ### Claim 1 An audio system comprising: a cartilage conduction transducer coupled to a pinna of a user of the audio system; a microphone positioned at an entrance to an ear canal of the user; and a controller configured to: instruct the cartilage conduction transducer to present a test sound; receive an audio signal that was detected by the microphone responsive to the test sound; determine a head related transfer function (HRTF) for the user using a model, the test sound, and the audio signal, wherein the model maps combinations of audio signals and test sounds to corresponding head related transfer functions (HRTFs); generate audio content using the HRTF; and instruct the cartilage conduction transducer to present the audio content to the user. ### Claim 2 (depends on 1) The audio system of claim 1, wherein the cartilage conduction transducer is configured to present the test sound at a test position on the pinna of the user. ### Claim 3 (depends on 2) The audio system of claim 2, wherein the model maps the combinations of the audio signals and the test sounds to the corresponding HRTFs for various test positions of the cartilage conduction transducer. ### Claim 4 (depends on 1) The audio system of claim 1, wherein the audio system is further configured to: prompt the user to move the cartilage conduction transducer to each of a plurality of test positions on the pinna, wherein at each test position the audio system is configured to present one or more respective test sounds by the cartilage conduction transducer and receive one or more corresponding audio signals detected by the microphone. ### Claim 5 (depends on 4) The audio system of claim 4, wherein at each test position the audio system presents a plurality of test sounds, and each test sound is the same. ### Claim 6 (depends on 4) The audio system of claim 4, wherein at each test position the audio system presents a plurality of test sounds and at least one test sound of the plurality of test sounds is different from another test sound of the plurality of test sounds. ### Claim 7 An audio system comprising: a cartilage conduction transducer coupled to a pinna of a user of the audio system; a microphone positioned at an entrance to an ear canal of the user; and a controller configured to: instruct the cartilage conduction transducer to present a test sound; receive an audio signal that was detected by the microphone responsive to the test sound; determine geometric information describing the pinna of the user using a model, the test sound, and the audio signal, wherein the model maps combinations of audio signals and test sounds to corresponding geometric information that describes the pinna of the user; generate audio content using the geometric information; and instruct the cartilage conduction transducer to present the audio content to the user. ### Claim 8 (depends on 7) The audio system of claim 7, wherein the cartilage conduction transducer is configured to present the test sound at a test position on the pinna of the user. ### Claim 9 (depends on 7) The audio system of claim 7, wherein the model maps the combinations of the audio signals and the test sounds to the corresponding geometric information for various test positions of the cartilage conduction transducer. ### Claim 10 (depends on 7) The audio system of claim 7, wherein the audio system is further configured to: prompt the user to move the cartilage conduction transducer to each of a plurality of test positions on the pinna, wherein at each test position the audio system is configured to present one or more respective test sounds by the cartilage conduction transducer and receive one or more corresponding audio signals detected by the microphone. ### Claim 11 (depends on 10) The audio system of claim 10, wherein at each test position the audio system presents a plurality of test sounds, and each test sound is the same. ### Claim 12 (depends on 10) The audio system of claim 10, wherein at each test position the audio system presents a plurality of test sounds and at least one test sound of the plurality of test sounds is different from another test sound of the plurality of test sounds. ### Claim 13 (depends on 7) The audio system of claim 7, wherein the controller is further configured to: determine a head related transfer function (HRTF) for the user using the geometric information. ### Claim 14 (depends on 13) The audio system of claim 13, wherein the controller is further configured to: perform a simulation that uses the geometric information to determine the HRTF. ### Claim 15 A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform steps comprising: instructing a cartilage conduction transducer to present a test sound, the cartilage conduction transducer coupled to a pinna of a user of an audio system; receiving an audio signal that was detected by a microphone responsive to the test sound, the microphone positioned at an entrance to an ear canal of the user; determining a head related transfer function (HRTF) for the user using a model, the test sound, and the audio signal, wherein the model maps combinations of audio signals and test sounds to corresponding head related transfer functions (HRTFs); generating audio content using the HRTF; and instructing the cartilage conduction transducer to present the audio content. ### Claim 16 (depends on 15) The computer-readable storage medium of claim 15, wherein the cartilage conduction transducer is configured to present the test sound at a test position on the pinna of the user. ### Claim 17 (depends on 16) The computer-readable storage medium of claim 16, wherein the model maps the combinations of the audio signals and the test sounds to the corresponding HRTFs for various test positions of the cartilage conduction transducer. ### Claim 18 (depends on 15) The computer-readable storage medium of claim 15, wherein the steps further comprise: instructing the audio system to prompt the user to move the cartilage conduction transducer to each of a plurality of test positions on the pinna; and instructing the cartilage conduction transducer to present, at each of the plurality of test positions, one or more respective test sounds. ### Claim 19 (depends on 18) The computer-readable storage medium of claim 18, wherein the steps further comprise: instructing the cartilage conduction transducer to present a plurality of test sounds at each of the plurality of test positions, and each of the plurality of test sounds is the same. ### Claim 20 (depends on 18) The computer-readable storage medium of claim 18, wherein the steps further comprise: instructing the cartilage conduction transducer to present a plurality of test sounds at each of the plurality of test positions, wherein at least one test sound of the plurality of test sounds is different from another test sound of the plurality of test sounds.