A notification device that continuously vibrates a membrane or uses a piezoelectric element is called what?

The correct answer focuses on the functionality of the device in question. A notification device that continuously vibrates a membrane or employs a piezoelectric element is typically categorized as a buzzer. Buzzers generate sound through the rapid movement of a diaphragm or membrane, which can vibrate to create audible alerts. The use of piezoelectric materials allows for efficient sound production and can be found in various electronic devices due to their compact size and low power consumption.

Horn devices, on the other hand, are designed to project sound over longer distances and tend to have a more pronounced and forward output due to their design, which is less about continuous vibration and more about amplification of sound waves. Sirens are often used for emergency alerts and usually create a broader range of tones rather than relying solely on a vibrating membrane. Lastly, light indicators serve a different purpose altogether by providing visual notifications instead of audible alerts.

Understanding these distinctions clarifies why the notification device in question is best identified as a buzzer.