The use of camera work during the shower scene in Alfred Hitchcock's psycho creates the scene to appear as though she is being stabbed even though we actually never see the knife pierce through the flesh.
The editing is very important to make the film give of the atmosphere desired for example if there hasn’t been a fast paced montage of shots in a while the chance is there will be something about to happen or scare the audience. The use of continuity editing and jump cuts are usually used by horror films so the audience are more engaged. However sometimes other editing is used to give other desired atmospheres such as dissolves linking two scenes together can show a link between objects and people.
Don’t look now shows jump cuts are incredibly effective when relating objects to characters. The smudging of the red in the picture relates to the little girls red raincoat and her drowning. Its all very effectively done, setting the initial tension imediately and engaging the audience.
Sounds are very important towards creating the desired atmosphere and setting a tension within the audience who are made to feel jumpy. Usually diegetic sounds are used against absolute silence making the loudness of a burst of action or jumpy scene even more tense. Sounds such as footsteps, heart beats, breathing ect. Are all diegetic and iconic in horror films.
In the Texas chainsaw massacre the opening sounds to the start of the film are very important as they contrast the landscape picture with sudden clashes of symbols. Another use of contrasting sounds is the scene where they pick-up the hitch hiker and as he cuts himself the music continues to play quite country and chilled music against the carnage caused when he self harms.