무향실에 있어서의 음압레벨과 거리정위와의 관계

Abstract

According to a lot of investigations, distance perception is influenced by many important cues such as sound pressure level, reflections from the room surface, binaural difference (ITD and ILD), a kind of sound source, and head related transfer functions (HRTF). Two psychoacoustical experiments on auditory distance perception were conducted to examine the effectiveness of the sound pressure level loudness as one of the physical cues in the auditory distance perception under a constant loudspeaker`s output level and a constant sound level at the subject`s position in the absence of reflections in an anechoic room. Our experimental results showed that the perceived distance of sound image is closer than actual sound source distance with the constant loudspeaker`s output level and the constant sound level. Futhermore, the perceived distance of a sound image with constant sound level increased when the actual distance increases up to approximately 2 m while the perceived distance saturated when the sound source distance exceed 2 m. On the other hand, when the condition of loudspeaker`s output level was kept constantly, the perceived distance of sound image increased up to around 3m, longer than the conditions of constant sound level at the subject`s position. We found that the change in the loudness as a function of distance plays an important role in the auditory distance perception in the absence of reflections..