from training.npr.org: http://training.npr.org/audio/butt-cut-what-a-glossary-of-production-terms/
'Butt cut what?' A glossary of production terms
Let’s say you are producing an audio story, and you’re asked to dip the ambi under the track, butt cut the next two acts, and then sweep up and maintain the ambi. If that sentence is confusing, this glossary is for you. Terms for producing and mixing audio go back to the days of cutting real tape with razor blades, but most of them have lived on into the era of digital production.
Ambience (n) — The pervasive sound at a location. (E.g. Traffic on a road. Doors slamming. Sounds of a demonstration. Birds and wind in a forest.) Can be used as an actuality itself or mixed under narration or other actualities. Also known as “ambi” or “nat sound” or less commonly as “sfx.” [Though, to be clear, ambience is not “sound effects”! It is real sound, not faked.]
Butt Cut (v or n) — To place one actuality immediately after another, rather than dividing them with copy or ambience. Often used to create a transition point, reinforce a point or demonstrate a contrast.
Cross Fade (v) — To fade out one sound while fading in another – in order to make the transition seamless. Usually performed in the background, under other tape. When performed in the clear, a cross fade can indicate a transition.
In the clear (adj) — When sound is in the foreground without competition from any other sound. Used for ambience or actualities. (E.g. A reporter’s mixing instructions might say, “Maintain ambi of gunshots in the clear for 4 secs.”)
Post (v or n) — v: To bring up a sound at a specific point so that it is in the foreground. Used for actualities or ambience. (E.g. “Post ambi after politician says, ‘I’m fighting for you!'”) n: The point at which the sound appears. (E.g. “Hit the post.”)
Rollover (n) — The recorded feeds of a program that occur after the initial live broadcast. The original live show is recorded and then fed again to allow stations flexibility in scheduling. Rollovers are frequently updated to fix mistakes and to add new information.
Split-track (n) — An interview with different audio in the left and right channels. For example, in the field, a producer or engineer might record the host in the left channel and the guest in the right channel. This allows for independent control of levels during production. Split-tracking is a great tool — but audio must be mixed onto both channels, or “summed,” before it can be broadcast.
Tape sync (n) — A variation of a split-track recording. In the case of an interview, the guest speaks to the host/reporter over the telephone. The producer/engineer goes to the scene and records what the interviewee says (or the guest records him/herself with a smartphone app — see photo). The guest’s side of the conversation is then combined or “sunk” with the host’s side of the conversation. To the listener, it sounds like the host and the guest are in the same room.
Track/Voice Track (n) — The reporter’s narrative, read from their script.
Alison MacAdam is the Senior Editorial Specialist on the NPR Training team, where she focuses on audio storytelling. She previously edited NPR’s All Things Considered.