This document discusses different types of sound design techniques used in film and TV production. It identifies selective sound and ambient sound as two techniques used to emphasize key sounds and set atmospheric tones. It also outlines other sound elements like sound bridges, sound effects, diegetic sounds originating from visible on-screen sources, non-diegetic added sounds, synchronous sounds matching actions, and asynchronous soundtrack music. The document notes voiceovers can be used to inform audiences or misdirect narratives, and that theme music and musical scores are employed to develop characters and set moods, while strategic use of silence can provoke viewer reaction.