A character is listening to music at the end of a film, and as the screen fades you expect the music to end but it doesn't. In fact, it reverbs: it becomes louder, clearer, of purer tone. That's because, now, it's for you. You're not listening to a character listen to it, so it doesn't have to abide to realism of the situation it was being played in and can be as high quality as possible. It is not necessarily done at the end of a work, it can be done deliberately to indicate a Diegetic Switch within a scene or across scenes to suggest that the characters are no longer hearing what the audience is. It can also be done In-Universe when the sound switches between different sources. Other situations include narration, where the first part of a speech is being delivered to characters before switching to a Voice Over or a direct speech to the audience. In a similar way, sometimes a character may seem to be soliloquising before the sound reverbs and the words are now distinctly recognised as being given to the audience. The idea behind this is that when the sound was playing In-Universe it was "trapped", and so tinny. A large reason to change the sound depth can be due to aesthetically technical issues — if the sound is coming from a radio on the other side of the room to the camera in the work, the sound quality is not going to be very pure. It may also be obscured by white noise. When the sound becomes background noise, it is not being constricted. The sound, once non-diegetic, is almost guaranteed to be Fake Loud, as the space it is being played in is much emptier than when it was in universe. The Diegetic Switch version may be commonly used to signify that this really is the end of the work, or to set up for this before switching back in. The technique does not require a Diegetic Switch, as the same effect can be achieved when alternating the source a sound is coming from In-Universe, often for similar reasons if done well, or to give the meaning between different characters. If a work has a particularly unskilled foley editor, the difference between recorded speech (on set) and ADR speech (studio recording) can be identified by the difference in sound quality. See also Music Box Intervals, when segments within a song sound as if they are coming from a different source.
- One of the promotional materials for Black Mirror when it moved to Netflix was "Welcome to the Darkness", that starts out with what seems to be a narrator talking to people watching within the screen. Then the sound gets muffled, the screen pulls back to show the man on a phone screen being held by the same guy, whose voice is now more refined than before so that the audience knows he isn't now — and probably wasn't before — talking to some in-universe but instead directly addressing the viewer. What he's talking about? Not being any better than the people we see on screen because our true selves are only revealed when we look into the screen gone dark.
- The Family: An example without diegetic switch — the film uses this technique across a Diegetic Sound Bridge by moving the song that Belle is listening to on her walkman in one scene to be the music coming from a boombox in the next. The sound quality is higher in the second scene because it's not playing through earbuds, the reverb also suggesting that the second scene is a musically-induced memory. As the song dies out from the radio, however, the perfect garden party memory itself shifts to be a nightmare, the new sound continuing into the next scene when Belle's dad startles awake in bed.
- Hairspray: Happens many times In-Universe when moving from the live-recordings of The Corny Collins Show to people watching it on television, accompanied with the image moving to black-and-white 4:3 to show the period of the setting.
- RV: Each member of the family sings a different song in an attempt to drown each other out. Jamie's music ("Little GTO" by Ronnie & The Daytonas) wins out when the sound switches to non-diegetic. The song starts as non-diegetic, high quality, then switches to low quality as it's being played out of earbuds in-universe, then switches back to high quality as it becomes non-diegetic again.
- In the Black Mirror episode "Hang the DJ", the song "Panic!" by The Smiths is playing in the pub where Frank and Amy meet at the end. At first it's barely heard and it gets louder as their eyes meet, but when the episode ends and the credits roll it switches to high quality audio, perfectly timed with the single-lyric chorus "Hang the DJ, Hang the DJ..." starting. This could signify either Frank and Amy hanging their DJ and getting their happy ending, or the events of the episode about to start again, hopefully the first, for the audience who have just been through romantic-comedy hell.
- Happens in the Grey's Anatomy episode "You Haven't Done Nothin'". Alex plays a voicemail from Meredith and it is suggested to be an overlay as it has the same sound quality as the next scene which shows Meredith recording it. When the sequence returns to Alex the sound is crackling to suggest it is actually being played through his phone this time. The scenes needed to be ordered in this way to not ruin the reveal with Alex putting in his plea, so the shift reverb occurs at the second cut to tell the audience that even though the voicemail began before, Alex is only now hearing it for the first time, too. The message then becomes a Voice Over Letter that Amelia has written to Owen, featuring lyrics from the background song ("dont you worry, there's still time") that gets Bonus Points for being even clearer since the voiceover obviously can't hear it, the song giving the audience the implicit meaning of everyone's words, before becoming spoken in voice over by Maggie for Richard about his effective demotion, cut over a shot of him giving a Rousing Speech to the staff that suggests they all support him, then shifting back to regular quality as Meredith finishes recording the message and finally becomes a voice over when Alex finishes listening to it, in this moment to suggest the message has really got to him, though it is later revealed that he wasn't really paying attention, hence the voiceover.
- In Sesame Street All-Star 25th Birthday: Stars and Street Forever!, at the end of the "Tough Guy Helpline" sequence, Ronald Grump walks off while a music cue starts playing before the special switches to Oscar's worm Slimy watching television, with the music cue now sounding like it's coming from the TV itself.
- Notably averted in The End Of The Fucking World so that the audience doesnt know what speech is actually James speaking and what he is thinking until the scene is replayed from Alyssa's perspective, adding to his characterization as a genuine sociopath since his filter and deadpan levels could be constantly changing.
Hello, Unknown Troper. You'll need to get known to lend a hand here.