Active localization of virtual sounds

A simple virtual sound display built around a microcomputer and analog hardware is described. The display implements most of the primary cues for sound localization in the ear-level plane. Judging both from informal observations by users and from objective data obtained in an experiment on homing to virtual and real sounds, it is concluded that simple displays like the one described are effective in creating the impression of external sounds to which observers can locomote with ease; in particular, this means that simulation of the direction-dependent spectral shaping effects of the pinnae is not a necessary requirement for extracranial sound localization.