Earmuffs are a popular form of hearing PPE (personal protective equipment). However, when combined with other pieces of PPE, they can lose their effectiveness.
For instance, if safety eyewear is worn with earmuffs, the sound barrier will be slightly broken at the point where the eyewear frame goes beneath the earmuff to hook over the ear.
Research by Bacou-Dalloz Hearing Safety Group found that an eyewear frame that is thicker than two millimeters can cause some significant decline in the effective attenuation of the earmuffs. Thus, workers who wish to use earmuffs should select safety or prescription glasses with thin frames.
Hard hats can also interfere with earmuffs because of the over-the-head headband. With standard hard hats, a cap-mounted earmuff will work. Full-brim hard hats are more difficult. Cap-mounted earmuffs will not work, so multi-position earmuffs – allowing under-chin or behind-head headbands – are recommended.
Faceshields may also not allow enough clearance for the ear cup or the headband. A neckband earmuff may work.
Finally, with a hood respirator, the hood may make contact with the earmuff shell, transmitting rubbing noises into the shell. Some earmuffs have lower profiles that may allow enough clearance.