Electret microphones enable communication and recording in devices including telephones, smartphones, desktop computers, headsets, recording systems and more.
This piezoelectric device makes continuous sound when a voltage is applied.
This is a PC internal BIOS motherboard small speakers alarm dupont head computer case buzzer speaker.
An active buzzer with a concussion internal source- so long as it will be called an energized. Program easy to control- SCM can let a high-low sound- while passive buzzer did not.