The Elevation Illusion in Virtual Audio

Abstract

Virtual audio involves headphone presentation of sound that appears to originate from an external location. Perception of elevation is known to be less accurate for virtual audio than for real sources. Anecdotal evidence suggests that at least some listeners have a pronounced tendency to consistently perceive the virtual audio as elevated higher than intended. The present study was conducted to investigate and compare errors in perception of elevation for virtual and real sources. Eight subjects listened to sounds presented through loudspeakers (behind an acoustic curtain) and through headphones (as virtual sources), and reported their perceived elevation for each sound. Five elevations were used (two above, two below, and one at ear level). The results show near perfect performance for perception of elevation for the loudspeaker condition. Perception of elevation was far less accurate for the virtual sources, and some subjects consistently perceived virtual sources higher than intended.