No, not that kind of vibrator! This kind of vibrator is an alerting device. Usually it's a small, handheld or clip-on radio receiver that receives signals from sensors capable of detecting various sounds or events. The sensors include a transmitter that signals to the receiver that they have detected the sound or event they were designed to detect.
For example, you might wear the small receiver and stategically place sensor/transmitters around your house to alert you to a phone ringing, a baby crying, a door bell ringing, someone knocking at your door or even other events like a car in the driveway or an oven beeping. When one of the sensor/transmitters is triggered it sends a radio signal to the receiver which then vibrates in a pattern that lets you know which signal was triggered. Some receivers also have lights that indicate which signal was triggered.
Learn more about other alerting devices.