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.

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.

This component typically consists of a small electric motor with an off-center weight fixed to its output shaft.