Diegetic/non diegetic sound

Diegetic Sound:

1. Voices of characters.
2. Sounds made by objects in the story.
3. Music that you can see and hear is coming from an instrument or jukebox etc.

Diegetic sound is any sound that is physical. So like a man banging on the table is frustration and you hear the sound.

Digetic sound can be either on screen or off screen depending on whatever its source is within the frame or outside the frame.

Basically, diegetic sound is actual sound. Not sound effects.

Non-Diegetic Sound:

Non-Diegetic sound is sound that cant be "seen" in a way. It's sound thats not physical and that is added in as like sound effects are for dramatic affect, a narrators commentary or mood music of some sort.

The difference between diegetic and non-diegetic sound all depends on if its been added in as an extra or the sound was captured there and then on camera. A play with diegetic and non-diegetic conventions can be used to create a horror type theme, or to surprise the audience like some comedy films do.

Another term for non-diegetic sound is commentary sound.

The film "Thor" you can see both Diegetic and Non-Diegetic sound being used. There is some Diegetic sound is from 1:11 - 1:17 where Thor and his father are arguing. Loki also gets involved. The Non-Diegetic sound is the music/soundtracks and sound effects in which there is a lot of throughout the trailer. Here is the web address to the trailer: 

https://www.youtube.com/watch?v=YSC9CjSYvYA

For the second film i chose to do "Grown Ups". Grown ups had diegetic sound throughout the trailer including speech, footsteps and background sound etc. The non diegetic sound is basically the commentary, sound effects and music/soundtrack. Here is the web adress to the clip:

https://www.youtube.com/watch?v=cjfuK5QJyEQ