User:SOTO/Forum Archive/The Reference Desk/@comment-110.174.166.224-20150115073856/@comment-1432718-20150115160419
It's been a while since I listened to the soundtracks, so I checked out one soundtrack and one DVD (The Web of Fear) to see if I could answer some of your questions.
Soundtracks: Narration occurs to introduce characters, describe situations (like the web around the TARDIS), and describe events, such as fights. However, because the soundtrack continues to play with no interruption, narration doesn't occur when there is dialogue. For instance, when the TARDIS doors are open and Jamie is trying to close them, there is a lot of dialogue, therefore no narration.
DVD: The soundtracks for DVDs include still photos, so they apparently felt there was no need for narration. They do use techniques like zooming in or out of a photo to suggest action.
Like I said, it's been a while, and I only looked at one story, so my comments might not be completely accurate.