Vibrating alert
A vibrating alert is a feature of communications devices to notify the user of an incoming connection or message. It is particularly common on mobile phones and pagers and usually supplements the ring tone. Most 21st-century mobile phones include a vibrating alert feature, as do smartwatches.
Vibrating alerts are primarily used when a user cannot hear the ringtone or wants a more discreet notification. However, when a device is placed on a hard surface, the noise caused by a vibrating alert can often be as loud or louder than a ringtone.
[Image:Vibramotor.jpg|thumbnail|right|Vibrating alert motor]
The vibrations are produced by an electronic component called a vibration motor. This component typically consists of a small electric motor with an off-center weight fixed to its output shaft.