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 for generating binaural signals for rendering audio comprising:
memory storage;
a head sensor configured to measure head orientation data relative to a reference position;
a first database having at least one room impulse measured to include one of Binaural Room Impulse Response (BRIR) data or Binaural Room Transfer Function (BRTF) data for a target room;
a second database having filters comprising transfer functions to convert a BRIR for a first reference position to a BRIR for a second reference position, which is different than the first reference position; and
a processor configured to combine filters from the second database with impulse responses from the first database to generate a BRIR for a second group of virtual speaker locations.
2. The system as recited in claim 1 , wherein the second group of virtual speaker locations corresponds to a second room.
3. The system as recited in claim 1 , wherein the second database comprises rotation filters.
4. The system as recited in claim 1 , wherein the second database comprises filters derived by a division operation.
5. The system as recited in claim 1 , wherein a plurality of entries in the second database are derived by interpolation.
6. The system as recited in claim further comprising audio rendering circuitry configured for rendering the output binaural signal.
7. A method for generating a binaural audio signal based on at least one spatial audio position comprising:
receiving an input spatial audio direction comprising at least one second spatial audio position;
determining a deviation of the input spatial audio direction relative to a reference position; and
using the deviation to access a first database comprising transfer functions representing the conversion of a BRIR from a first reference position to the at least one second spatial audio position.
8. The method as recited in claim 7 , wherein the deviation includes a change in head orientation to include at least one of rotation, inclination, or tilt.
9. The method as recited in claim 1 , wherein the deviation includes a change in head orientation to include at least one of inclination or tilt.
10. The method as recited in claim wherein interpolation is used to create a portion of a second database.
11. The method as recited in claim 10 , wherein the interpolation is performed in the frequency domain.
12. The method as recited in claim 7 , wherein the BRIR is a Binaural Acoustic Impulse Response (BAIR).
13. The method as recited in claim 7 , wherein a personalized BRIR for the listener is generated by mapping audio related physical properties for the listener to similar metadata in a third database for a group of individuals.