Voice-activated radio-dispatched alarm

A voice-activated radio-dispatched alarm, or VARDA-alarm, is a type of burglar alarm that, when activated or "tripped", broadcasts the type of the alarm and the transmitter location over the local police radio frequency using a pre-recorded audio message.[1]

In 1968, the voice-activated radio dispatched alarm (VARDA), was invented. It is a portable device that, when activated, will broadcast a message to the dispatch channel, allowing officers to immediately respond to the scene for further investigation. Although the VARDA was originally designed for law enforcement applications such as repeat break-ins, domestic violence issues and metal/equipment theft, its concept has been adapted over time to address a variety of needs in the private sector.[1]

This type of alarm is installed for special monitoring at the location of recent burglaries. When the alarm is activated, it will set off a voice message directly over a radio frequency (generally a non-primary frequency), repeating the message several times. Example: "Burglary in progress, 231 Union Street." The message will repeat itself until the alarm is reset, usually manually.