Abstract: A smoke detector includes a housing having therein a sensor for detecting smoke, an arrangement responsive to detection of smoke for producing an audio signal and an audible sound at an audio frequency, a telephone dialer circuit, a telephone jack on the housing for coupling the dialer circuit to a telephone line, and an arrangement responsive to the occurrence of the audio signal for causing the dialer circuit to automatically dial the telephone number. The telephone number may be a single specified digit, or a multi-digit number stored in a last number dialed memory of the dialer circuit. After dialing of the telephone number, the audio signal is supplied to the telephone line regardless of whether an answer occurs at the remote end. After a predetermined time interval, a timer circuit releases the telephone line, waits a predetermined time interval, causes the telephone number to be dialed again, and then causes the audio signal to again be applied to the telephone line.