During searches, sound sweeps are used to:

Sound sweeps are conducted to detect any noise that might indicate a subject's presence. This approach is essential during search and rescue operations because it allows searchers to pick up on sounds that may signify distress or the presence of an individual in need of assistance. These sounds could include calls for help, signaling noises, or other indicators that someone is nearby.

By focusing on listening rather than just moving through the area, searchers can effectively locate individuals who may be incapacitated or unable to signal visually. Understanding the importance of sound can greatly enhance a search team's efficiency and effectiveness in finding missing persons in various environments.

Other options, while relevant to different aspects of search and rescue, do not directly address the primary purpose of sound sweeps, which is to actively listen for signs of a subject's presence.