Norwood have created a set of ear protectors with inbuilt microphones and earphones for communication in noisy environments. It all communcates through a base station which just has a speaker, couple of buttons and a set of lights to indicate the number of headsets connected.

I built an embedded java daemon which runs inside the box and connects headsets, lights the appropriate lights, gives acoustic messages about the state of the system, and reacts to the button presses.

This was built in java using JNI to connect to the operating system and communicate with the hardware