The purpose of this research is to further the understanding of auditory distance perception so that distance illusory software can be designed more effectively. Current methods of creating auditory distance illusions are inadequate. A sound source distance illusion is usually only crudely achieved with significant timbre altering processes. These processes are not conveniently implemented and are often computationally expensive. A method for a sound source distance illusion that is timbrally transparent, computationally efficient, and easily implemented is desirable.
This research investigates how a change in the early reflection pattern received by a listener affects the perceived distance of a sound source. In these investigations, the number of early reflections provided and the directions from which these early reflections arrive are changed. To conduct these investigations, software that makes use of simulated early reflections for a distance effect is designed. Audio samples processed with this software are presented to listeners in an online survey. Data from the survey is used to resolve speculations about human distance perception.
This research shows that the perceived sound source distance changes as the number of early reflections provided changes. It also shows that a change in early reflection spatial distribution does not cause a change in the perceived distance of a sound source. Furthermore, the research suggests that a distance illusion can be achieved with as few as 3 early reflections.