How is sound used to create tension in Thrillers?

Sound is often used to create tension in thriller films, the film I will be analysing the sound from is the opening clip to Sin city and how it creates tension and raises suspense.
The use of the close up shot of the gun (2 minutes 18) and the diegetic sound of the gunshot establishes the genre because they are both common features of film noir and crime thrillers. The use of the gun also supports the Mise en scene and mood of film noirs and thrillers. A gun can be seen to symbolise justice and victory or could symbolise war and unrest.

This also links to the use of pathetic fallacy and the diegetic sound of the rain. It foreshadows danger and the rain and diegetic thunder set a depressing and dark tone and mood which are common features of film noir and compliment the genre. The non-diegetic sound of the dripping drainpipe and the wind create a feeling of dread and doom and make the audience tense and anxious to see what is going to happen. This successfully creates tension because dripping water is an uneasy sound and will put the audience on edge.

The whispering of the characters sets an uneasy tone because they are alone on a rooftop so why would they need to be whispering? It creates tension because the audience are listening in closer because they want to know what it going to happen. This is effective at drawing the audience in and placing them on tenterhooks because they are unsure of what is going to happen, and they may feel like they don't want to know but at the same time they're listening closer which makes them tense which is the idea of a thriller opening.

The non-diegetic use of smooth jazz (starting at 13 seconds) as the background track reinforces the film noir genre. The non-diegetic sound of the birds seems a little out of place because they are on a dark rooftop in the middle of a city at night. They show they’re in a city by the landscape above the rooftop they are standing on but they also show it with the use of the non-diegetic sound of the cars which suggest traffic (4 seconds) on the ground below. It also sets a sense of claustrophobia because it suggests they are trapped in a city, the audio code helps to set the scene and genre and create a sense of claustrophobia and tension.

 Tension is also created with the sound of the footsteps (15 seconds) at the start of the scene because we don’t know who is approaching on the rooftop as his face is half hidden in shadow, it creates a sense of mystery and secrecy which again is typical of a film noir.

The dialogue is male dominated and he seems to have an emotionless tone, (43 seconds) even after he’s killed her (2 minutes 22) he doesn’t seem to show any emotion which suggests he could be the antihero because we know nothing about him except from the fact he has just killed a woman on a rooftop in the middle of a city on a dark night. The characters are established a little through their dialogue. The male dominance is also shown with the male character narrating over the top of the scene which is normally used to show a characters feelings or emotions but in this case his tone is blank and he just narrates the events and tells us how he is feeling but with little to no sentiment in his voice.

Analysing the sound from this opening clip has allowed me to study a successful audio code and learn effective methods of creating tension and raising suspense, all of these I will need to do in my thriller opening so studying this clip has allowed me to look at techniques I could use in my own thriller opening.