Hearing protectors - Safety requirements and testing - Part 5: active noise reduction ear-muffs.

听力保护器。安全要求和试验。第5部分：有源降噪耳罩。

youdao

Objective To observe the sound attenuation effect of several kinds of hearing protectors (earplugs and earmuffs) in an infrasound generator sound field.

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。

youdao

Objective To observe the sound attenuation effect of several kinds of hearing protectors (earplugs and earmuffs) in an infrasound generator sound field.

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。

youdao