Elvex DeTune electronic earmuffs improve communications by allowing the user to adjust the frequency range transmitted through the circuitry and speakers. The user can set the sound level inside the headset up to 85 dB. Two control knobs are used to filter out the high and low frequencies. When the filters are set to inactive the user hears as if no protection was being worn, except for the maximum sound limiter.Elvex Corp., Bethel, CT.