Question 1
The use of silence and diegetic sounds at the beginning of this film initially made it feel not terrifying which, to me, conveyed the man’s reaction/emotions to his situation however, later on they were transformed into sounds used to create tension. When the man notices the clown, a non-diegetic sound pops up, hinting that he feels less comfortable and indirectly tells the viewer to feel uncomfortable as well (this was what I interpreted). It pops up again when we are shown the clown which suggests that this is no ordinary clown you should be laughing at but a clown that could potentially harm you. If these sounds were not inserted in the film, I would probably think otherwise. When the clown sits near the man, a barely audible music starts playing to intensify the feeling of horror during their conversation. All in all, the sounds in the film were used to amplify the feeling of fear, especially the unnerving silence which I thought was the dominant sound throughout the whole film.
If memory serves, the Japanese version of The Grudge felt almost similar to this film in terms of sound.
In this scene from the movie, silence was also the dominant sound along with the use of diegetic sounds to create tension and the feeling of terror leading from it (1:34). The non-diegetic sounds were also used to amplify the character’s reactions/emotions.