Sound in film-making:

“Sound” refers to everything we hear in the film

Types of Sound:

-Diegetic sound

-Non-diegetic sound  

-Parallel sound

-Contrapuntal sound

The important thing to remember is that whilst you as a viewer might not consider some of these sounds to be that important.

Non-diegetic sound

-Red's narration

-The brewing instrumental build

-Incidental music

Sound whose source is visible on the screen or whose source is implied to be present by the action of the film:

-Voices of characters