The most effective solution is the Alpha Communications/ Cornell 4200 series audio-visual Rescue Assistance System, which signals the need for evacuation assistance. The 4200 series includes voice communication which is initiated by simply depressing the call station button, which transmits the signal to a master station. A single pulse tone and a flashing light signals the caller that the alarm has been received. The master station may then talk to the caller. The caller need not take any other action to communicate with the master station, which is an important feature when a caller is under stress in an emergency situation. For additional safety, a live 'fault' lamp will signal at the central (master) station, if the wiring has been faulted.