A system is provided that includes a base station of a security system having a wireless transceiver, a processor of the base station that periodically transmits a beacon under a 6LowPan/Iot protocol defining an information transfer super frame having a plurality of time division multiple access (TDMA) slots, a plurality of remotely located devices, each with a sound transducer and a wireless transceiver that exchanges messages with the base station within the TDMA slots of the super frame, and a respective processor within each of the plurality of remotely located devices that determines a sound activation pattern and a location of a multicast slot within the super frame from the beacon, detects an activation message within the multicast slot, and activates the sound transducer based upon the location of the multicast slot in accordance with the sound activation pattern.