Personalized calibration of an in-ear device
An in-ear device occludes an ear canal of an ear of a user. The in-ear device is configured to be calibrated such that the user perceives audio content as though the in-ear device is not occluding the ear canal. A transducer of the in-ear device presents audio content, and an inner microphone of the in-ear device detects sound pressure data within the ear canal. A controller of the in-ear device determines a blocked sound pressure at the entrance to the ear canal based on sound pressure data from an outer microphone. The controller generates sound filters custom to the user based in part on the detected sound pressure within the ear canal and the blocked sound pressure at the entrance to the ear canal. The controller adjusts audio content using the sound filter, and the transducer presents the adjusted audio content to the user.
1. A method comprising:
presenting audio content via a transducer of an in-ear device, the in-ear device occluding an ear canal of an ear of a user;
detecting sound pressure data within the ear canal via a microphone of the in-ear device;
determining a blocked sound pressure at an entrance to the ear canal using sound pressure data from a microphone of the in-ear device that is configured to capture sound external to the ear;
determining a length of the ear canal based on the detected sound pressure within the ear canal;
determining, based on the length of the ear canal, an open sound pressure at the entrance to the ear canal;
determining a transfer function characterizing a ratio of the blocked sound pressure at the entrance to the ear canal to the open sound pressure at the entrance to the ear canal;
generating a sound filter customized to the user based in part on the transfer function, the sound filter configured to remove effects of the ear canal being occluded on presented audio content;
adjusting audio content using the sound filter; and
presenting, via the transducer, the adjusted audio content to the user.
2. The method of claim 1 , wherein a model is used to determine the length of the ear canal based on the detected sound pressure.
3. The method of claim 2 , further comprising:
estimating the open sound pressure at the entrance to the ear canal based on the transfer function and the blocked sound pressure at the entrance to the ear canal; and
estimating, based on the estimated open sound pressure at the entrance to the ear canal, an open sound pressure at the ear drum of the ear.
4. The method of claim 3 , wherein adjusting audio content using the sound filter comprises applying a gain generated based on the estimated open sound pressure at the ear drum, an estimated blocked sound pressure at the ear drum, and the blocked sound pressure at the entrance to the ear canal.
5. The method of claim 1 , wherein the audio content that is adjusted using the sound filter is detected from a local area around the in-ear device and by the microphone of the in-ear device that is configured to capture sound external to the ear.
6. The method of claim 1 , further comprising:
responsive to detecting a change in a position of the in-ear device:
regenerating the sound filter;
adjusting audio content using the sound filter; and
presenting, via the transducer, the adjusted audio content to the user.
7. The method of claim 1 , wherein the in-ear device is a hearing aid.
8. An in-ear device comprising:
a body configured to occlude an ear canal of an ear of a user;
a transducer coupled to the body and configured to present audio content;
a plurality of microphones coupled to the body, wherein one microphone of the plurality of microphones is configured to detect sound pressure data within the ear canal and a second microphone of the plurality of microphones is configured to detect sound external to the ear; and
a controller configured to:
determine a length of the ear canal based on the detected sound pressure within the ear canal,
determine, based on the length of the ear canal, an open sound pressure at the entrance to the ear canal,
determine a transfer function characterizing a ratio of the blocked sound pressure at the entrance to the ear canal to the open sound pressure at the entrance to the ear canal,
generate a sound filter customized to the user based in part on the transfer function, the sound filter configured to remove effects of the ear canal being occluded on presented audio content,
adjust audio content using the sound filter, and
instruct the transducer to present the adjusted audio content to the user.
9. The in-ear device of claim 8 , wherein the controller is further configured to use a model to determine the length of the ear canal based on the detected sound pressure.
10. The in-ear device of claim 9 , wherein the controller is further configured to:
estimate the open sound pressure at the entrance to the ear canal based on the transfer function and the blocked sound pressure at the entrance to the ear canal; and
estimate, based on the estimated open sound pressure at the entrance to the ear canal, an open sound pressure at the ear drum of the ear.
11. The in-ear device of claim 10 , wherein adjusting audio content using the sound filter comprises applying a gain generated based on the estimated open sound pressure at the ear drum, an estimated blocked sound pressure at the ear drum, and the blocked sound pressure at the entrance to the ear canal.
12. The in-ear device of claim 8 , wherein the audio content that is adjusted using the sound filter is detected from a local area around the in-ear device and by the second microphone of the in-ear device that is configured to detect sound external to the ear.
13. The in-ear device of claim 8 , wherein the controller is further configured to:
responsive to detecting a change in a position of the in-ear device:
regenerate the sound filter;
adjust audio content using the sound filter; and
present, via the transducer, the adjusted audio content to the user.
14. The in-ear device of claim 8 , wherein the in-ear device is a hearing aid.
15. A non-transitory computer readable medium configured to store program code instructions, when executed by a processor, cause the processor to perform steps comprising:
presenting audio content via a transducer of an in-ear device, the in-ear device occluding an ear canal of an ear of a user;
detecting sound pressure data within the ear canal via a microphone of the in-ear device;
determining a blocked sound pressure at the entrance to the ear canal using sound pressure data from a microphone of the in-ear device that is configured to capture sound external to the ear;
determining a length of the ear canal based on the detected sound pressure within the ear canal;
determining, based on the length of the ear canal, an open sound pressure at the entrance to the ear canal;
determining a transfer function characterizing a ratio of the blocked sound pressure at the entrance to the ear canal to the open sound pressure at the entrance to the ear canal;
generating a sound filter customized to the user based in part on the transfer function, the sound filter configured to remove effects of the ear canal being occluded on presented audio content;
adjusting audio content using the sound filter; and
presenting, via the transducer, the adjusted audio content to the user.
16. The non-transitory computer readable medium of claim 15 , wherein the instructions further cause the processor to perform steps comprising using a model to determine the length of the ear canal based on the detected sound pressure.
17. The non-transitory computer readable medium of claim 15 , wherein the instructions further cause the processor to perform steps comprising:
estimating the open sound pressure at the entrance to the ear canal based on the transfer function and the blocked sound pressure at the entrance to the ear canal; and
estimating, based on the estimated open sound pressure at the entrance to the ear canal, an open sound pressure at the ear drum of the ear.