摘要
目的观察几种护耳器 (耳塞、耳罩 )对次声发生器次声场的隔声效果。方法在次声发生器工作现场 ,采用挪威 840型实时分析仪 ,分别测量B .K .41 2 8型模拟头裸耳 (无防护 )和闭耳 (佩戴护耳器 ) 2种状态下的线性声压级 (dBSPL)、A声级 (dBA)、次声级及 4～ 2 0 0 0 0Hz 1 /3倍频程声压级 ,2种状态声压级的差值为护耳器的隔声值。结果 3种耳塞对次声的隔声值为 1 6 .4～ 1 9.4dB ,对线性声压级和A声级的隔声值比较接近 ,分别为 2 0 .0～ 2 1 .6dB和 2 3 .0～ 2 5 .6dBA ;两种耳罩对次声基本无防护效果 ,隔声值分别为 0 .4dB和 - 0 .3dB ,对线性声压级的隔声值分别为 7.2dB和 3 .2dB ,对A声级的隔声值分别为 2 2 .4dBA和 1 9.5dBA ;耳塞 +耳罩复合防护 ,对次声频和低频声防护无相加效果 ,隔声值主要取决于耳塞的隔声性能 ,但对中、高频声有明显的相加隔声效果。
Objective To observe the sound attenuation effect of several kinds of hearing protectors (earplugs and earmuffs) in an infrasound generator sound field. Method Using a real time analyzer (Type 840 made in Norway), linear sound pressure level (dBSPL), sound level (dBA), infrasound level and 1/3 octave band sound pressure level (4～20 000 Hz) were measured on an artificial head (B.K. Type 4128) under two conditions: with or without hearing protectors (i.e. naked and closed ear). The difference between sound pressure levels, sound levels, and infrasound levels under the two conditions was designated as sound attenuation values. Result The sound attenuation values of 3 types of earplug tested were: 16.4～19.4 dB for infrasound level, 20.0～21.6 dB and 23.0～25.6 dBA for linear sound pressure level and sound level, respectively. When 2 types of earmuff were used, the sound attenuation values for infrasound level were 0.4 and -0.3 dB, for linear sound pressure level were 7.2 and 3.2 dB, and for sound level were 22.4 and 19.5 dBA, respectively. It suggested that there was no hearing protection to infrasound. When a combination of earmuff and earplug was used, the protection to infrasound and low frequency sound showed no additive effect. It indicated that sound attenuation was mainly dependent on the earplug, but for middle and high frequency sound the additive effect was significant. Conclusion The results indicate that earplugs provide more effective protection against infrasound exposure than earmuffs.
出处
《航天医学与医学工程》
CAS
CSCD
北大核心
2003年第2期110-114,共5页
Space Medicine & Medical Engineering
关键词
次声
护耳器
耳塞
耳罩
隔声效果
infrasound
hearing protector
earplug
earmuff
sound attenuation value
