Vibrating alert

A vibrating alert is a feature of communications devices to notify the user of an incoming connection or message.¹ 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 (a noisy environment or through hearing loss) or wants a more discreet notification (such as in a theatre). 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.

The vibrations are produced by an electronic component called a vibration motor (alternatively called a haptic actuator). This component typically consists of a small electric motor with an off-center weight fixed to its output shaft.