Earmuff: A device, shaped like a headset, that is mounted on a bow to cover the ears to attenuate noise. The noise attenuation of ear muffs can reach 10-40 decibels, which is suitable for environments with high noise, such as processing workshops of shipyards and metal structure plants, engine test benches, etc. In recent years, some countries have also fixed earmuffs on welding masks or used them together with communication headphones or earphones. Earplugs and earmuffs can be used separately or in combination. The combined use can increase the noise attenuation by 5~15dB compared with the single use.