These may include motor races, crowd noise in indoor sports arenas, car radios, power tools, electronic appliances and live music performances . When leisure activity sound levels often exceed 90dB, this is the danger zone. Use the OSHA guidelines to monitor the duration of exposure. It is important to note that most headphones offer no protection. Foam HPDs have maximum attenuation at high frequencies.
Ear muffs require a solid shell and seal around the ear to attenuate noise.