Persons with normal hearing always can detect some sound while wearing HPDs because bones in the head conduct sound. The most common hearing protection devices are muffs worn over the ears, and plugs worn in the ears. Muffs may be more comfortable to wear for long periods of time than plugs. Muffs should not be worn with eyeglasses or any other obstruction that will reduce their effectiveness. Hearing plugs may be disposable or designed for re-use.
Disposable plugs are especially popular for short wearing periods or infrequent use.
They are inexpensive and can be thrown away when the job is completed or they become dirty. However, disposable plugs can be relatively expensive if hearing protection is required on a regular basis. In this case, a non-disposable plug or muff, meant to be washed and stored after each use, is a good choice. For general use, look for NRR of 25 or greater. Remember that the rating was obtained in perfect conditions after wearers had received careful fitting instructions.