Preferred sound intensity increase for sensation of half distance

Two experiments are reported that examine the preferred increase in intensity for creating a percept of half auditory distance from a reference. The results of both experiments indicate that the use of an inverse square law (increments of 6 dB) is not the best signal-processing method for this purpose. The application of the results is potentially useful towards the software design of 3-D auditory display systems that manipulate the perceived distance of auditory inputs in relationship to actual distances of physical objects.