以吸声构造提升隧道内声学系统语言清晰度

Improving the speech intelligibility in a traffic tunnel with acoustically absorptive structures

以长715m隧道为例,在铺设具有高度吸声能力的隧道内壁装修材料后,可以提升与紧急抢救有关的隧道内语言清晰度。如以国际标准ISO/TR3352的语言干扰级SIL进行评价则有6.7dB降噪量,此降噪量相当于在满意的语言清晰度下的最大沟通距离增加了1倍以上。若依照IEC60268-16标准进行语言清晰度评价,以男声广播的语言传输指数由0.26(恶劣级)提升至0.50(普通级),以女声广播的语言传输指数则由0.28(恶劣级)提升至0.52(普通级)。在铺设具有高度吸声能力的隧道内壁装修材料后,不论以男声或女声广播的语言传输指数皆可符合美国国家防火协会在火灾警报法规NFPA72中所要求的最低标准值0.50。

The speech intelligibility is significantly improved after applying 3.5 m height uf the CEMCOM acoustical material on the curved concrete side wall of 715 m long traffic tunnel. The maximum communication distance is more than doubled in the tunnel as the speech interference level is reduced 6.7 dB according to ISO/TR 3352 standard. According to IEc 60268 -16, by considering the reverberation only in the highway tunnel, the revised speech transmission index for male voice is increased from 0.26 （bad rating） to 0.50 （air rating） and for female voice is increased from 0.28 （bad rating） to 0.52 （fair rating）. After the acoustical engineering project, the speech transmission index for both male and female voices in the tunnel is no less than 0.5 as a minimum requirement in NFPA 72.