AUDITORY PERCEPTION OF SPATIAL EXTENT IN THE HORIZONTAL AND VERTICAL PLANE

This article investigates the accuracy with which listeners can identify the spatial extent of distributed sound sources. Either the complementary frequency bands comprising a source signal or the individual grains of a granular synthesis-based stimulus were distributed directly on discrete loudspeakers. Loudspeakers were arranged either on the horizontal or the vertical axis. The algorithms were applied on white noise, an impulse train, and a rain drops stimulus. Absolute judgments of spatial extent were obtained separately for each orientation, algorithm, and stimulus using three different magnitudes of horizontal or vertical extent. Horizontal spatial extent judgments varied systematically with physical extent for all conditions in the experiment. The correspondence between perceived and actual vertical extent was poor. The time-based synthesis algorithm resulted in significantly larger judgments of spatial extent irrespective of orientation and stimulus compared to the frequency-based algorithm.