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A viewer follows an explanation in which each idea appears as it is spoken, so nothing is read ahead. A lesson fails when the slide says everything at once. The room reads the whole slide, finishes before the teacher does, and stops listening. DeckTalk holds each part of a diagram back until the voice reaches the word for it, so attention has nowhere else to go.

What a viewer gets

  • One idea at a time, in the order the explanation needs, because a reveal waits for its word.
  • Equations typeset on the page from a data-tex attribute, drawn as the voice says them and never spelled out as symbols.
  • A sentence that appears word by word under the voice, through data-text="spoken", when the wording itself is the point.
  • Chapters a learner can jump between, a transcript page to read afterwards, and captions for a viewer who needs them.

What the author writes

KaTeX ships inside the wheel, so an equation needs no download and no content delivery network. A diagram is plain HTML and CSS with data-cue and data-reveal attributes on the parts that appear, and data-describe gives each of those parts one sentence that the transcript prints.

The workflow

1

Start a lesson project

decktalk init --example lesson writes a worked lesson with an equation, which is the fastest way to see the shape of one.
2

Write the explanation, then the diagram

Say the thing, then draw the thing. Every reveal needs a word in script.md that names it, which is what Writing for the ear is about.
3

Build it without voice

decktalk build --no-voice paces the whole lesson with placeholder narration, so the timing is settled before a credit is spent.
4

Check every landing

decktalk verify reports each reveal that came late, early or not at all, and decktalk screenshots writes a PNG per slide so the text contrast and the crowding can be read.
5

Reteach one section

A better sentence is an edit and decktalk build --only 2. The rest of the lesson keeps its takes.
Read Quickstart for the first build, Design a slide for the reveal effects and the camera, and Accessible video for the captions, the chapters and the transcript a course platform asks for. The other two use cases with worked examples are technical tutorials and product demos.