Elvex Level Dependent muff uses the same technical components and features as Elvex foldable muff for impulse noise.The communications features allow an officer to have close range communications in select continuous noise environments. The microphones on the outside of the ear muffs "listen to" the environment and can amplify weak sounds, and the gain limiter suppresses sounds exceeding 82 dB. An impulse (or impact) filter electronically eliminates impulse sounds by closing down the circuitry in four milliseconds, and opening the circuitry again in about 1/4 second (in order to prevent echo effect). This feature makes Elvex hearing protection very effective on the shooting range. The gun shots are eliminated, but the shooting instructor can still be heard.