FADE IN – TV – Film – Radio - Music Recording
a) Term used in picture editing or VISION MIXING. Refers to the way one picture gradually comes into vision usually from a black screen, or from a title sequence in movies.
b) In SOUND EDITING refers to the way one sound is gradually added to or replaces another. In radio, music is often faded in under speech. It comes in at a very low volume and then increases to the normal level as the speech finishes.