Abstract: The invention is a control apparatus for use in an electronic siren circuit which generates a plurality of siren and intelligible audio outputs. The control apparatus includes a control module of relatively small size which may be mounted in a limited space proximate to an operator and a relatively larger, receiver module which may be mounted in any convenient location in a vehicle. The control module and remote receiver module are coupled together by a transmission line. Circuitry is provided in the control module and receiver module for producing binary coded control signals and for decoding these signals respectively to produce control signals in the receiver module. Circuitry is also provided for multiplexing intelligible audio signals over the same transmission line and for discriminating between the binary coded control signals and intelligible audio signals and conditioning the power module to reproduce same using the high power amplifier circuit of the siren.