Gaps left at the script stage cost less than describing afterwards
Aliases: AD production timing · AD breathing room · pre-production AD gaps
What it is
Leaving breaths in the script and the cut, before cameras roll, is cheaper than adding audio description afterwards — which usually means recutting, building a paused extended version, or dropping a set of visual facts. What costs is not “someone reading a few lines.” It is discovering that talk already fills the clock and description has nowhere to go. Timing is the cost.
Why it happens
Measure dialogue density only in post and it is often above ninety percent speaking time. A standard mix will not take more words. All three exits are expensive: recut to make air (picture, performance, music all move); build an extended version (a second track, a player that can pause, a new running time to distribute); write less (quality drops; the job is unfinished). If the storyboard already leaves two to four seconds of action without talk, description can enter the same standard mix. One master then also serves people who cannot see the frame.
This is the same timing pattern as “accessibility at acceptance.” Once the structure locks, you are repairing the container, not the sentences. For AD, the container is time. Gaps are budget, not style.
Studying it
Audit production. Do not invent a lab effect size. Take two pieces of similar duration and similar visual-event density, one wall-to-wall talk, one cut with air, and compare description labour hours, whether an extended version was required, and the fraction of visual events finally covered.
Independent variables: dialogue density, whether gaps were flagged in script review, whether an extended track was in scope. Dependent variables: describer hours, extended-version go/no-go, coverage of critical visual events, number of reworks.
A plot of “insertable seconds per minute” predicts the late bill better than asking a director whether they thought about access.
Where it stops holding
Released archive that cannot be reshot has already lost this saving; only extend or accept holes. Live news almost cannot leave seams for description. Drama whose talk is the performance cannot be thinned for AD — that wants an extended track, not a pretence that the standard mix still has room. Animation and game cutscenes written wall-to-wall have made the same decision at script: there will be no cheap post.
Applying it
- Add a script-review check: does a critical visual land on the same second as dialogue? If yes, mark it and change the line or the action’s duration.
- In the cut, leave two to four speakable seconds on silent action. Do not wallpaper those seconds with talk.
- If standard gaps are clearly short, fund an extended track and pause points before release. Do not discover after distribution that nothing fits.
- How to check: plot dialogue density and drop the pre-listed visual keyframes on it. Every frame in a dense stretch either gets a recut or already has extended budget. Otherwise post will pay.