Making an audiobook from recorded chapters

A memoir read for the family, a children’s story, a course to listen to in the car: an audiobook is easiest to record one chapter at a time, and easiest to listen to as one file that a player can skip through chapter by chapter and that remembers where the listener stopped. That file is usually an M4B. These tools take you from the separate recordings to the finished book in your browser, without an editor or an upload.

1. Record a file a chapter, and number them

Record each chapter as its own file, and start each file name with its number: 01 Opening.wav, 02 The Storm.wav and so on, using 01 rather than 1 if there are ten or more. The Audiobook Maker puts the chapters in that order and uses the rest of each name as the chapter’s title, so good names now save typing later.

Record in a quiet, soft-furnished room, the same room each time, with the microphone the same distance from you. Chapters recorded on different days sound different if anything changes.

2. Trim each chapter

Open each recording in the Audio Trimmer. Move Start to just before you begin reading and End to just after you finish, leaving about half a second of quiet at each end so chapters don’t run into each other. Tick Mono: a voice gains nothing from stereo, and the book will be half the size. Save as WAV, which keeps the full quality for the next step.

3. Make every chapter the same loudness

A listener shouldn’t have to reach for the volume between chapters. Open each trimmed chapter in the Loudness Meter, choose one Target for all of them, and Save at this loudness as WAV. −19 LUFS (mono podcasts) suits a spoken book listened to on a phone. If the message says a chapter could only go part of the way, it has sharp peaks (a cough, a laugh, a hard “p”): trim them out, or use a limiter in an audio editor, then measure it again.

If you’re sending the book to a publisher or store, follow its own specification and check with its own tools. Audible’s ACX, for example, sets limits on RMS level, peaks and background noise, which these tools don’t measure.

4. Get the cover ready

Audiobook covers are square. Open the picture in Image Convert / Resize, crop it to a square, set Width to 1400 or more (stores often ask for at least that), and save it as JPEG. Players show the cover small, so check that the title can still be read when the picture is the size of a thumbnail.

5. Put the book together

Open the Audiobook Maker and choose all the chapter files at once. Check the order and the chapter titles, and change any that are wrong: a title like Chapter 3: The Storm reads better in a player’s chapter list than a file name does. Fill in the title, author and narrator, add the cover, and choose Mono (speech) at 64 or 96 kbit/s. Make the audiobook saves the .m4b: about 30 MB an hour at 64 kbit/s.

6. Check it before you share it

Open the .m4b in Audio Tags: the table shows its length, Tags shows the title, author and narrator (as the composer), Chapters lists every chapter with where it starts, and the cover is under Pictures. Then play it in the app your listeners will use: skip through a few chapters, and check that the cover and titles show as you expect, since players differ in what they read.

For a player that doesn’t take M4B, such as some car stereos, the Audiobook Splitter saves the finished book as one numbered file a chapter, as M4A or MP3.