The ZPI-4 is a four-zone Touch Tone controlled paging system capable of switching a line level signal to amplifiers or an amplified signal to speakers. The ZPI-4 features balanced audio circuitry throughout for low noise and compatibility with balanced paging system inputs and outputs. In addition, separate level controls are provided for paging and background music, and background music can be disabled on a per-zone basis. An additional night bell is provided which can be activated by a dry contact closure, a ringing C.O. or a ringing analog PABX/KSU station.