Head-related transfer function determination using reflected ultrasonic signal

1 . A method comprising:

transmitting an ultrasonic beam towards an ear of a user of a headset;

detecting a reflected signal generated by an interaction of the ultrasonic beam with the ear;

obtaining a three-dimensional geometry of the ear of the user;

updating, by a controller, the three-dimensional geometry of the ear based on the reflected signal; and

determining, by the controller, a head-related transfer function (HRTF) for the user based in part on the three-dimensional geometry of the ear.

2 . The method of claim 1 , wherein transmitting the ultrasonic beam towards the ear comprises:

beamforming outputs of a plurality of speakers on the headset to create and directionalize the ultrasonic beam, the plurality of speakers forming a phased array.

3 . The method of claim 1 , wherein the reflected signal is generated by the interaction of the ultrasonic beam with an obstructed portion of the ear.

4 . The method of claim 1 , wherein the three-dimensional geometry of the ear was previously generated using one or more images of the ear, and the updated three-dimensional geometry of the ear includes information corresponding to an obstructed portion of the ear included in the one or more images.

5 . The method of claim 4 , wherein updating the three-dimensional geometry of the ear comprises:

identifying an area of low confidence in the three-dimensional geometry of the ear that was generated using the one or more images of the ear;

identifying a corresponding area in a second three-dimensional geometry of the ear that was generated using the reflected signal;

determining a confidence level for the corresponding area; and

based on the confidence level for the corresponding area being higher than a threshold confidence level, augmenting the area of low confidence in the three-dimensional geometry of the ear with the corresponding area.

6 . The method of claim 1 , further comprising:

determining, by the controller, an equalization filter for the user based in part on the three-dimensional geometry of the ear.

7 . The method of claim 1 , further comprising:

transmitting a sub-ultrasonic beam towards the ear;

detecting a second reflected signal generated by an interaction of the sub-ultrasonic beam with the ear; and

updating, by the controller, the three-dimensional geometry of the ear based on the second reflected signal, the updated three-dimensional geometry of the ear to include information about an obstructed portion of the ear.

8 . The method of claim 7 , wherein the ultrasonic beam and the sub-ultrasonic beam are transmitted concurrently towards the ear.

9 . The method of claim 1 , further comprising:

identifying an area of low confidence in the three-dimensional geometry of the ear;

identifying a corresponding area in a second three-dimensional geometry of the ear that was generated using one or more images;

determining a confidence level for the corresponding area; and

based on the confidence level for the corresponding area being higher than a threshold confidence level, augmenting the area of low confidence in the three-dimensional geometry of the ear with the corresponding area in the second three-dimensional geometry of the ear.

10 . The method of claim 9 , wherein the second three-dimensional geometry of the ear based on the one or more images is determined by a server, the server communicatively coupled to the headset.

11 . The method of claim 1 , wherein: obtaining the three-dimensional geometry of the ear of the user comprises determining a first three-dimensional geometry of the ear based on one or more images; and

updating the three-dimensional geometry of the ear comprises:

determining a second three-dimensional geometry of the ear based on the reflected signal; and

inputting the first three-dimensional geometry of the ear and the second three-dimensional geometry of the ear into a machine learning model, the machine learning model trained to update the three-dimensional geometry of the ear based on both the first three-dimensional geometry of the ear and the second three-dimensional geometry of the ear.

12 . An audio system comprising:

a plurality of transducers, the plurality of transducers configured to transmit an ultrasonic beam towards an ear of a user;

one or more acoustic sensors, the one or more acoustic sensors configured to detect a reflected signal generated by an interaction of the ultrasonic beam with the ear; and

a controller configured to:

obtaining a three-dimensional geometry of the ear of the user;

update the three-dimensional geometry of the ear based on the reflected signal; and

determine a head-related transfer function (HRTF) for the user based in part on the three-dimensional geometry of the ear.

13 . The audio system of claim 12 , wherein the plurality of transducers includes a speaker with a port, and wherein the speaker is coupled to the port via an acoustic waveguide.

14 . The audio system of claim 12 , wherein the plurality of transducers forms a phased array and is further configured to beamform outputs to create and directionalize the ultrasonic beam.

15 . The audio system of claim 14 , wherein the phased array is on a single chip.

16 . The audio system of claim 12 , wherein the plurality of transducers is further configured to present audio content to the user based in part on the determined HRTF.

17 . The audio system of claim 16 , wherein, at a same time, a subset of the plurality of transducers is configured to present audio content and a different subset of the plurality of transducers is configured to transmit the ultrasonic beam.

18 . The audio system of claim 12 , wherein the plurality of transducers is further configured to transmit a sub-ultrasonic beam towards the ear, the one or more acoustic sensors is further configured to detect a second reflected signal generated by an interaction of the sub-ultrasonic beam with the ear, and the controller is further configured to update the three-dimensional geometry of the ear based on the second reflected signal, the updated three-dimensional geometry of the ear to include information about an obstructed portion of the ear.

19 . The audio system of claim 12 , wherein the audio system is integrated into a headset worn by the user.

20 . A non-transitory computer readable medium storing instructions that, when executed by a processor, cause the processor to perform steps comprising:

transmitting an ultrasonic beam towards an ear of a user of a headset;

detecting a reflected signal generated by an interaction of the ultrasonic beam with the ear;

obtaining a three-dimensional geometry of the ear of the user;

updating the three-dimensional geometry of the ear based on the reflected signal; and

determining a head-related transfer function (HRTF) for the user based in part on the three-dimensional geometry of the ear.