Abstract: A multiple phone ring boost circuit rings multiple subscriber telephones synchronized with a ring signal sent from a telephone company central office is connected to multiple subscriber telephones. A local generator creates a local ring signal, and a local generator sensing circuit determines if the local generator is functioning properly. A ring sensing circuit senses if a ring signal is being received. A switch connects the line leads to the subscriber leads in a first position, and connects the local generator to the subscriber leads in a second position. A control circuit varies the switch between the second and first positions. When the ring sensing circuit detects an incoming ring signal and the local generator sensing circuit detects a properly functioning local generator, the switch is placed in its second position. When the ring signal pauses, the control circuit places the switch in the first position.