Abstract: An alarm communication device and a method for mutual recognition between a first alarm unit and a second unit connected therebetween by a public switching unit is provided. The first alarm unit is connected to the public switching unit via at least one first communication line and the second unit is connected to the public switching unit via at least one second communication line. The method includes the steps of detecting a ring signal at the first alarm unit, detecting a caller identification (ID) signal provided by the public switching unit, determining a caller ID number from the caller ID signal, matching the caller ID number with at least one predetermined number and when the caller ID number is matched to one of the at least one predetermined number associated with the second unit, executing a predetermined procedure associated with the matched at least one predetermined number.

Abstract: An electronic monitoring system particularly useful as a telephone babysitter comprises a monitoring unit connectable to the telephone line at the location to be monitored, and a portable sound-producing unit for actuating the monitoring unit from a remote telephone handset via the telephone line. The monitoring unit at the monitored location includes a microphone, a code detector detecting a predetermined code transmitted by the portable sound-producing unit, a keyboard for storing the telephone number of a selected remote telephone handset, a sound level comparator, automatic dialling means, and a microcomputer including a plurality of settable flags controlling the monitoring unit according to preprogrammed routines and in response to the transmission of preselected codes by the portable sound-producing unit.