The document discusses the different types of sounds used in TV drama, including diegetic sounds that come from within the world of the story and non-diegetic sounds that are added later for mood or emotion. It explains that dialogue, sound effects, and music make up the sound track and help create balance between the realism of the story world and the drama. Proper use of these sounds through techniques like stings, incidental music, and ambient noise can manipulate audiences' emotions and signal upcoming events to enhance dramas.