A device for coupling to a connector on an ear cup of a headset includes a mating connector corresponding to the connector of the headset. The mating connector includes a crossover conductor coupled to a first and a second terminal within the mating connector. One or more accessory circuits is provided by the device, including a lamp configured to direct light onto a surface external to the device or a position detection circuit usable to adjust three-dimensional audio signals to account for the direction the user is looking.