Silent Call manufacturer Sound Monitor.

The Sound Monitor may be placed in a room to alert the user to sounds such as a baby's cry, an appartment door buzzer, alarm clock, oven timer, etc.

The new improved SM1005-4 adds a delay circuit so that loud sounds that are very brief (such as a door slamming) will not activate it even if those sounds are in fact above the detection threshold. When the sound monitor detects a sound that is above its adjustable detection threshold, it sends a signal to any Silent Call receiver (except the Shakeup), activating the vibrator and/or visual alert.

Operates on 2- AAA batteries (included)