What is the primary function of acoustic sensors?

Acoustic sensors primarily function to detect sound waves, which includes recognizing specific frequencies associated with certain events. In the context of security systems, one of the significant applications of acoustic sensors is to detect the sound of breaking glass. These sensors are tuned to identify the unique frequency patterns produced when glass shatters, making them effective for protecting areas with windows. Their ability to distinguish these frequencies allows them to reliably trigger alarms when glass is broken, thereby serving a critical role in intrusion detection.

The other options highlight functions that are typically carried out by different types of sensors. For instance, monitoring temperature changes is primarily done by thermal sensors, while humidity levels are monitored by hygrometers. Motion detectors, on the other hand, utilize infrared or microwave technologies to sense movement, rather than relying on sound. Therefore, the primary identification of glass breakage frequencies is what establishes the correct choice as the defining feature of acoustic sensors.