Room tone
Recorded 'silence' of the actual room, used to fill edit gaps so cuts don't drop into unnatural dead air.
See it
What it is
Room tone is thirty to sixty seconds of the room recorded with nobody talking, captured on the same mic, in the same position, at the same gain as the takes. It is not silence: it is the air handling, the traffic outside, the faint hum of the room's own character.
You reach for it when editing creates holes. Cut a stumble out of a narration and the gap goes to absolute digital silence, which the ear hears as a jarring dropout. Patching that gap with room tone (or laying a continuous room tone bed under the whole dialogue track) makes the edit vanish. It also feeds noise reduction tools, which need a clean noise-only sample to learn the profile from.
Gotcha: room tone is worthless if it does not match. Different room, different mic distance, or a changed gain setting and the patch sounds like a patch. Grab it before anyone strikes the setup, every single location, every single time.
Ask AI for it
Fill the silent gaps in this dialogue edit with matched room tone: take the cleanest speech-free stretch from the same recording, loop it under the entire dialogue track at its original level, and crossfade every join by 200 to 500 ms so no seam is audible. Do not use generated noise or a stock ambience, and do not leave any region at absolute digital silence.