複合カフェにおける火災警報音の聞こえについて

摘要

Recently young people often use headphones with portable audio devices. When they use headphones to listen to music, it can be difficult for them to hear some surrounding sounds such as fire alarm. The difficulties may lead them to a dangerous situation. In this study, hearing thresholds of university students during listening to music with headphones were measured and the sound pressure level of fire alarm sounds was measured in a cafe. The level of the alarm sound was as small as 40dB SPL at some points in the caf?. We found that people may fail to hear the alarm sound when they were listening to music with headphones.%音楽を聴取するためにヘッドホンを用いることで、周囲音が聞き取りづらくなる。また、それによって危険を回避することも難しくなる。本研究では複合カフェ店舗内において、ヘッドホンオーディオ聴取時に火災警報音がどの程度聞こえるのかについて、店舗内での計測実験と火災警報音の聴覚閾値の測定を行った。消防法の基準を辛うじて満たす条件にて実測した火災警報ベル音の最小値は約40dB であり、ヘッドホンオーディオ聴取時では聞こえない可能性があることが確認できた。