Electronic Earmuffs - Active, Passive, and Radio
Electronic earmuffs use a variety of technologies to provide both hearing protection and additional functions. Some electronic earmuffs use their battery power only to supply AM/FM radio. Others go a step further and allow you to plug in an audio device through an auxiliary port or BlueTooth connection. Typically, the volume level of the input will not exceed 82dB.
An Active Electronic Earmuff, however, is smarter. It's always working, and it's usually doing two jobs simultaneously. First, an active earmuff will amplify ambient sounds. Often the level of help it provides is adjustable. Second, when a sudden noise considered potentially harmful (usually 82dB or higher) is detected, it instantly blocks that sound from passing through to the ears.