Use of Sound in Short Films

Types of Sound:

Diegetic: Sound whose source is visible on screen or implied by an action.
                      - Character Dialogue
                      - Object noise (e.g. Phone ringing or kettle boiling)
                      - Music coming from on screen (e.g. Stereo)

Non-Diegetic: Sound whose source is neither on screen or implied by a reaction.
                      - Narrator Commentry
                      - Sound effects used for dramatic effect.
                      - Soundtrack music/ mood music

Use of Sound:

In short films, non-diegetic sound is used for atmostpheric purposes, for example in action films there is usually pulse racing mood music to emphasise the drama and Life & Death situations.

For Example:

Loop (https://www.youtube.com/watch?v=dVGzK5M967Q)
In this short, the majority of sound is diegetic because the sound is constantly implied by the female lead, whether it is her dialogue or her sounds associated with the scene e.g. Gun shots. Non-diegetic sound is used during the opening titles. The music is tense and enigmatic which is the theme of the short film.

Connection (https://www.youtube.com/watch?v=87B1tz3KdOg)
Yet again in this short, the majority of sound is diegetic because it is implied; the sound is associated with airports and aviation. The Diegesis (narrative) of the film are crucial because in this case it tells the story of a lost foreigner and busy actor who plays himself. It tells the story that one another is lost within translation. There is some soundtrack music (non-diegetic) which fills in silences between the characters to keep the audience interested.

Many short films work the same way as these two examples. It is uncommon for them to break 4th Wall narration, which is the thin line that exists between story and reality (it is often the character telling the story to the audience in a way that they know they are the character, in simpler terms they talk directly to the audience). This was a popular technique used in 80s and 90s programmes such as Malcolm in the Middle - we see Malcolm talk to the camera/audience expressing his embarrassment about his life and family. The use of this narration is not largely used in short films because it would waste time and is quicker to use specific camera angles, sound and quick snippets of dialogue that would give the same amount of narration.