Method for generating customized spatial audio with head tracking
A headphone for spatial audio rendering includes a first database having an impulse response pair corresponding to a reference speaker location. A head sensor provides head orientation information to a second database having rotation filters, the filters corresponding to different azimuth and elevation positions relative to the reference speaker location. A digital signal processor combines the rotation filters with the impulse response pair to generate an output binaural audio signal to transducers of the headphone. Efficiencies in creating impulse response or HRTF databases are achieved by sampling the impulse response less frequently than in conventional methods. This sampling at coarser intervals reduces the number of data measurements required to generate a spherical grid and reduces the time involved in capturing the impulse responses. Impulse responses for data points falling between the sampled data points are generated by interpolating in the frequency domain.
1. A system comprising:
at least one room impulse that includes one of Binaural Room Impulse Response (BRIR) data or Binaural Room Transfer Function (BRTF) data for a target room; and
filters comprising transfer functions to convert a BRIR for a first reference position to a BRIR for a second reference position,
wherein the filters are combined with the at least one room impulse to generate a BRIR for a second group of virtual speaker locations.
2. The system of claim 1 , wherein the second group of virtual speaker locations are outside of the target room.
3. The system of claim 1 , wherein the filters comprise rotation filters.
4. The system of claim 1 , wherein the filters are derived by a division operation.
5. The system of claim 1 , wherein the filters are in a second database, and wherein a plurality of entries in the second database are derived by interpolation.
6. The system of claim 1 , further comprising audio rendering circuitry configured for rendering an output binaural signal.
7. The system of claim 1 , further comprising a head sensor configured to measure head orientation data relative to a reference position.
8. A method comprising:
receiving an input spatial audio direction comprising at least one second spatial audio position; and
accessing, using a deviation of the input spatial audio direction relative to a reference position, transfer functions representing a conversion of a BRIR from a first reference position to the at least one second spatial audio position.
9. The method as recited in claim 8 , wherein the deviation includes a change in head orientation to include at least one of rotation, inclination, or tilt.
10. The method as recited in claim 8 , further comprising creating, using interpolation, a portion of a second database.
11. The method as recited in claim 10 , further comprising performing the interpolation in a frequency domain.
12. The method as recited in claim 8 , wherein the BRIR is a Binaural Acoustic Impulse Response (BAIR).
13. The method as recited in claim 8 , further comprising generating a personalized BRIR for a listener by mapping audio related physical properties for the listener to similar metadata for a group of individuals.
14. A method comprising:
measuring at least one room impulse that includes one of Binaural Room Impulse Response (BRIR) data or Binaural Room Transfer Function (BRTF) data for a target room;
converting, by filters comprising transfer functions, a BRIR for a first reference position to a BRIR for a second reference position; and
combining the filters with impulse responses to generate a BRIR for a second group of virtual speaker locations.
15. The method of claim 14 , further comprising using a division operation to derive the filters.
16. The method of claim 14 , further comprising deriving by interpolating a plurality of entries.
17. The method of claim 14 , further comprising rendering, using audio rendering circuitry, an output binaural signal.
18. The method of claim 14 , further comprising measuring, using a head sensor, head orientation data relative to a reference position.
19. The method of claim 14 , wherein the second group of virtual speaker locations is outside the target room.
20. The method of claim 14 , wherein the filters comprise rotation filters.