US Patent 9901758 Respiratory protection device

A respiratory protection device is provided that allows the wearers of a facepiece to smoothly have a conversation with each other. A respiratory protection device includes a facepiece. The protection device also includes a voice amplifier that includes a microphone and a speaker therein, a detection unit that directly or indirectly detects the inner pressure of the facepiece, a power source unit, and a control unit. The control unit controls so as to place the voice amplifier in an operational state or a non-operational state, based on a result of comparison of information from the detection unit with a determination reference in the control unit.