His system of acoustic radiators boosts the audio signal in the area of a room where a hearing impaired person sits, but keeps the same audio levels elsewhere.

The recorders are designed to emit an audio signal for up to a month.

It also has two phono stereo outputs for pass-through of the actual phono audio signal.

However, additional interference could come from the audio signal.

The audio signal was sent from an on-stage monitoring and control booth to the recording room over a heavy shielded cable.