A chapter is the smallest unit a listener actually navigates. They open the audiobook in the middle of Chapter 7, leave it open on the dishes, come back later. The publisher cares about that unit too: when you upload to a major audiobook platform, each chapter typically ships as a separate audio file with its own title metadata, and the index your distributor builds depends on those splits.
Somewhere between "writer ships an EPUB" and "listener taps Chapter 7," the chapter boundaries have to survive intact through every pipeline stage. Inside our pipeline, that survival is the boring part. It is also where misalignments compound, because every later stage assumes the prior stage got the chapter list right.
This post walks through what AudioProducer.ai does to keep the chapter unit intact end-to-end, and where it gets stretched.
The chapter is a unit, all the way through
Before we walk the pipeline stage by stage, here is what stays constant. From import to download, a chapter is:
