What is the function of sound monitors in audio surveillance?

The function of sound monitors in audio surveillance primarily involves picking up sounds in a room. These devices are designed to detect and capture audio from the environment, allowing investigators to listen to conversations and assess situations without being physically present. By effectively picking up ambient sounds, sound monitors can provide valuable information through audio clues, which can be critical in investigations.

While amplifying sounds, recording conversations, or intercepting telephone signals are related to audio technology, they do not accurately describe the primary role of sound monitors in the context of audio surveillance. Their core function revolves around the ability to capture and relay the sounds occurring within a particular space, making option C the correct choice.