A complement used by filmmakers in order to improve a scene.
- Diegetic sound
These sounds have a source which is visible in the screen, for example voices of actors, sounds made by objects in the history, etc.
- Non-diegetic sound
It is also called commentary sound and they coming from a source which is not visible on the screen, for example the voice of God, narrator's commentary, etc.
- Sound effects
Sound effects include artificial or natural sounds, except speech and music. For example, the sounds of a car accident, a fight, or an avalanche are made by using sound effects.