The generation and validation of high fidelity virtual auditory space

This paper reviews a number of the issues involved with recording the filter functions of the outer ear and subsequently using these functions to render virtual auditory space using headphones. The acoustical problems associated with recording within the confined tube of the auditory canal are considered for both specification of the head related transfer function and the headphone transfer function. The difficulties of acoustically validating the rendered VAS indicate the importance of validation using a powerful test of auditory performance. We describe such methods as used in our laboratory. The issue of individualised HRTFs is considered and two relevant experiments are described concerning the (i) mapping of the morphology of the outer ear to the filter characteristics and (ii) the subsequent manipulation of standard HRTFs.