US Patent 7840019 Estimation of head-related transfer functions for spatial sound representation

The estimation of an HRTF for a given individual is accomplished by means of a coupled model, which identifies the dependencies between one or more images of readily observable characteristics of an individual, and the HRTF that is applicable to that individual. Since the HRTF is highly influenced by the shape of the listener's outer ear, as well as the shape of the listener's head, images of a listener which provides this type of information are preferably applied as an input to the coupled model. In addition, dimensional measurements of the listener can be applied to the model. In return, the model provides an estimate of the HRTF for the observed characteristics of the listener.