Audiowell piezoelectric sound components include piezoelectric diaphragms and piezoelectric buzzers. They were widely used in various needs of the voice prompts or warnings occasions and devices, such as piezo sound alarm and piezo ringer.

 

Ultrasonic sensors (also known as transducers when they both send and receive) work on a principle similar to radar or sonar which evaluate attributes of a target by interpreting the echoes from radio or sound waves respectively. Ultrasonic sensors generate high frequency sound waves and evaluate the echo which is received back by the sensors. Sensors calculate the time interval between sending the signal and receiving the echo to determine the distance to an object.