When we watch a scene in a film, we observe the following consistencies:

1. Chromaticity
2. Lighting
3. Ambient sound

There are two reasons why we perceive these consistencies:

Film production rules:

1. Camera placement rule [180 degree rule]:

The cameras on a set, are placed on the same side of an imaginary line, to preserve the spatial relationships between objects in a scene, across shots. The effect of overlapping fields-of-view of the cameras is to produce a chromatic consistency to the filmed scene.

2. Lighting continuity: The lighting across shots in a scene must be consistent in order to give the viewer the impression that the shots were filmed at the same time.

The psychology of audition:

Albert Bregman did pioneering experiments on the psychology of human audition. Here are few of his observations:

1. Sound properties change smoothly and gradually over time.
2. Changes affect all components of the sound.
3. Humans perform sequential grouping of sounds emanating from a single source (e.g. we are able to readily identify footsteps as coming from the same source.).

Bregman's observations indicate that sounds within scenes are perceived as internally consistent. However, he did not formulate the methodology for analyzing auditory scene changes.