System and method for converting passive protectors to ANR headphones or communication headsets
A system and method for converting a passive protector earmuff to a communication and/or active noise reduction (ANR) headset include mounting active components to a frame subassembly configured for insertion into the passive earcup to divide the earcup volume into a front cavity without additional passive leak paths and a back cavity having a volume that improves speaker/driver power efficiency with a resistive vent to atmosphere. An earcup having an external shell includes a frame configured for positioning within the external shell and having a first support adapted to contact an interior of the shell and a second circumferential support cooperating with a seal to contact an ear seal plate of the earcup to form the front and back cavities. The frame may support a speaker between the front and back cavity, and secure circuitry within the back cavity.
1. A headset comprising:
a circumaural earcup having a shell;
an acoustic damping membrane positioned on an interior surface of the shell;
a frame positioned within the shell to separate an interior volume of the shell into a back cavity between the frame and the shell and front cavity sealed from the back cavity, the frame configured to receive: a speaker extending between the front and back cavity, and processing circuitry in the back cavity; and
a communication microphone coupled to the processing circuitry.
2. The headset of claim 1 further comprising a sense microphone mounted to the frame and coupled to the processing circuitry.
3. The headset of claim 2 further comprising a resistive vent coupling the back cavity to atmosphere.
4. The headset of claim 3 further comprising an ambient microphone coupled to the processing circuitry.
5. The headset of claim 4 wherein the ambient microphone is integrated with the resistive vent and coupled to the processing circuitry.
6. The headset of claim 4 wherein the processing circuitry generates an ANR signal based on signals from the sense microphone and the ambient microphone and outputs the ANR signal to the speaker.