Hypersonic pulse
A hypersonic pulse was high-pitched sound of sufficient frequency to render a humanoid unconscious. 

In 2369, while the senior officers from the  were held hostage on Arkaria Base, a hypersonic pulse was created by Dr. Beverly Crusher. This was achieved by modifying the optical transducer of Lieutenant Commander Geordi La Forge's VISOR. The resulting pulse knocked everyone in the room apart from Data. ()

Physics