Sonic weapons are devices that use sound waves to incapacitate or deter individuals. They can emit high-frequency sounds that are uncomfortable or painful to hear, causing disorientation or discomfort. These weapons are often considered non-lethal and are used in crowd control or military applications. Some sonic weapons operate at lower frequencies, producing vibrations that can cause physical effects on the body. Examples include the Active Denial System, which uses millimeter waves, and various handheld devices designed for personal defense. Research continues into the effectiveness and ethical implications of using such technology in various situations.