An electrical amplifier unit which removably attaches to a gas mask and includes a microphone for detecting voice sounds emitted by the wearer of the gas mask, circuitry for amplifying the detecting sound, and a loudspeaker for emitting the amplified sounds externally of the mask. The associated components are contained within a housing that attaches sealably to the outlet port of a gas mask. The amplifier unit is quickly and easily attachable to commercially available gas masks without additional hardware and does not affect the structural and functional integrity of the host mask.