Discrepancy in Sound Source Direction Perceived Through Bone-conduction Headphones in Audio Frequency Band
Mamoru Iwaki, Haruya Sugihara · 2024
A previous study showed that the perceived directions of sound sources in the voice band presented through bone-conduction (BC) headphones are inclined toward the center compared with those for air-conduction (AC) headphones. BC headphones are thus unsuitable for use as hearing aids. However, the sound stimuli used were limited to pure tones between 500 Hz and 4000 Hz. In this study, we investigated the discrepancy in the perceived direction of sound presented through BC headphones over a wider frequency range (125-16,000 Hz). In experiments, an appropriate interaural level difference and interaural time difference for each direction were added to sound stimuli, and the stimuli were separately presented through AC headphones and BC headphones. Participant judgments of the directions revealed that the perceived direction through the BC headphones was still inclined toward the center compared with that for the AC headphones. The discrepancy was smaller in the lower bands and larger in the higher bands.