Diegetic and Non Diegetic sound- Charley

Diegetic and Non Diegetic sound is a very big part of filming.

Diegetic sound:
Diegetic sound is sound where the sourse is visible on screen.

voices of characters

sounds made by objects in the story

music represented as coming from objects

http://www.youtube.com/watch?v=fRI15yhjeNQ - this is an example of Diegetic sound, in the clip the sound present is coming from:

• The man phone ringing
• The mans voice
• Sound coming from the music stereo

As i have explained Diegetic sound is anything that is seen by the viewer and is present in the scene. The opposite to Diegetic sound is Non Diegetic sound.
Non diegetic sound is:

Sound whose source is neither visible on the screen or has been implied to be present in the action.
 

• narrator's commentary
• sound effects which is added for effect
• mood music
• a sound from offscreen

 Non-diegetic sound is shown as a sound coming from a source outside story.

Diegetic and Non Diegetic sound is used alot in film, to create many different effects for the viewer. For example, in horror films they use Non diegetic sound to create suspence.

http://www.youtube.com/watch?v=juVb1SDHWrk - This clip sums up Diegetic and Non Diegetic sound.