Efficient personalization of head-related transfer functions for improved virtual spatial audio

1. A method of generating a virtual audio signal for a listener, the method comprising:

estimating spherical harmonic coefficients based on an individual character of the listener;

comparing the estimated spherical harmonic coefficients to a distribution of known spherical harmonic coefficients, the known spherical harmonic coefficients of the distribution being derived from head related transfer functions of a plurality of individuals;

iteratively updating the estimated spherical harmonic coefficients and comparing the updated and estimated spherical harmonic coefficients to the distribution of known spherical harmonic coefficients until convergence; and

applying the individual character and the converged spherical harmonic coefficients to a mono-channel sound.

2. The method of claim 1 , further comprising:

measuring the individual character of the listener.

3. The method of claim 2 , wherein the measured individual character is a set of sample HRTF measurements arranged about a sagittal plane with respect to the listener.

4. The method of claim 1 , wherein the individual character is an interaural timing difference.

5. The method of claim 1 , wherein the individual character is at least one individual character includes a set of HRTF measurements, an anthropometric measurement, a spatial audio evaluation, or a combination thereof.

6. The method of claim 5 , wherein comparing the estimated spherical harmonic coefficients further comprises:

summing each estimated listener-specific spatial coefficient of the set and a corresponding one generalized spatial basis function; and

individually weighting each estimated listener-specific spatial coefficient of the set and the corresponding one generalized spatial basis function.

7. The method of claim 1 , wherein the distribution of known spherical harmonic coefficients comprises a database.

8. A method of generating virtual audio for an individual, the method comprising:

estimating a plurality of listener-specific coefficients by:

collecting at least one individual character of the listener; and

fitting the at least one individual character to a model trained with a database comprising listener-specific components from a plurality of measured Head-Related Transfer Functions;

constructing a listener specific Head-Related Transfer Function by:

summing each estimated listener-specific spatial coefficient of the set and a corresponding one generalized spatial basis function; and

individually weighting each estimated listener-specific spatial coefficient of the set and the corresponding one generalized spatial basis function; and

applying the listener-specific Head-Related Transfer Function to an audio signal.

9. The method of claim 8 , wherein the plurality of measured Head-Related Transfer Functions correspond to measurements from a plurality of listeners.