A buzzer is a mechanical, electromechanical, magnetic, electromagnetic, electro-acoustic, or piezoelectric audio signaling device. A piezoelectric buzzer can be driven by a wavering electronic circuit or other audio signal sources. A tick, blare, or ring can show that a catch has been squeezed.
Sirens and Alarms
A siren is a boisterous clamor making gadget. Common safeguard sirens are mounted in fixed areas and used to caution of cataclysmic events or assaults.