You're three chapters into listening back, and the cast works. Then the ship's captain gives his first order, and the voice is good, steady and clear, but it isn't the man you wrote. You pictured him older: a voice that has shouted over weather for forty years.
That's a casting note, not a line note, and it raises the question every author asks next: can you recast one character's voice in your audiobook without producing the book again? You can. Here is how.
The short answer
Open any chapter in the studio, open Martin, and say how you hear the character:
The captain should sound older and more weathered, like he's given orders all his life.
Martin, Midsummerr's AI audio director, rewrites the captain's voice description from your note, designs a new voice for him, and plays you the sample in the chat. Nothing you've already produced has changed at this point. You're auditioning.
If you like it, say "put it in this chapter" and Martin re-records the captain's lines in the chapter you're in, so you hear the new voice in the scene. If you don't, say what's off ("older, but too gruff, he should still sound kind") and Martin designs another. Your earlier voices are kept, so "go back to his old voice" brings the previous one back.
Martin is the AI audio director built into the Midsummerr studio, and Midsummerr is the only audiobook platform with one. Direct your audiobook by talking to it shows the chat in more detail.
Ready to try it on your own book?
Start with 5,000words free →The recast, step by step
A recast happens in stages, and you decide when each one happens. A new voice is something you hear first, then place.
| Your note to Martin | What Martin does | What changes in your audio |
|---|---|---|
| "Play me the captain's voice" | Plays the character's current sample in the chat | Nothing |
| "Make him older and more weathered" | Designs a new voice from your description | Nothing yet: you get a sample to audition |
| "Put it in this chapter" | Re-records the captain's lines in this chapter | This chapter, his lines only |
| "Use it for the rest of the book" | Asks you to approve, then re-records his lines in your finished chapters | His lines in those chapters; everything else stays |
| "Go back to his old voice" | Brings the previous voice back | The voice you had before |
The approval step is there because finished chapters are audio you already have. Martin shows you which character and how many chapters before anything runs, and only that character's lines are re-recorded. The narrator, the rest of the cast, the score and the sound effects stay as they are.
What a good casting note sounds like
A casting note describes a person, not an audio setting. The notes that land best say who the character is and how they come across:
- Age and life. "Older, a voice that's worked outdoors" gives a clearer target than "deeper".
- Texture and warmth. "Dry and precise", "warm but tired", "bright, quick, a little breathless".
- What the listener should feel. "She should sound kind even when she's giving bad news" tells Martin what the voice has to carry.
If the change you want is about one moment, it's a performance note rather than a recast. "He should whisper this line" or "angrier here" belongs on the line itself, and How to change one line of your audiobook covers that. A recast is for when you hear the whole character differently.
Auditioning voices by hand
Everything Martin does with a voice is also in the editor. Open the character from the Voices page, or from the character in the studio, and the voice dialog lets you:
- Hear the voices side by side. Play the character's current voice and the other voices offered for the part, then press Use on the one you want.
- Ask for more. More voices brings new options to hear for the part.
- Describe the voice. The pencil opens the character's voice description. Rewrite it ("older, gravelly, slow to anger") and Find voices returns options that match.
- Go back. Previous voices lists every voice the character has had, ready to restore.
When you switch a voice by hand, the chapters you've already produced show "Voices changed" in your chapter list, and Update voices re-records the lines of the characters whose voice changed. Martin is the faster path when you know how the character should sound but not which control gets you there.
Hear a cast first
Recasting matters most on a full-cast book, where every speaking part has a voice of its own. To hear what that sounds like before you start, listen to Five Children and It, produced in Midsummerr with a narrator and 51 character voices, from the five children down to the Psammead. How to make a full-cast audiobook covers casting from the start, and the features page shows the rest of the studio.
Try it on your own book
Upload a manuscript, generate a chapter, and find the character you hear differently. Open Martin and describe them. Recasting, auditioning and re-recording voices is free, until the cast sounds the way you wrote it.
FAQ
Does recasting a character regenerate my audiobook?
No. Only that character's lines are re-recorded, in the chapters you choose. The narrator, the rest of the cast, the music and the sound effects stay as they are.
Can I hear a new voice before it changes anything?
Yes. Martin designs the voice and plays you a sample in the chat first. Your audio changes only when you ask Martin to put the voice into a chapter, or when you press Update voices.
Can I get the old voice back?
Yes. Every earlier voice is kept. Ask Martin for the previous voice, or open Previous voices in the character's voice dialog and restore it.
Does recasting cost credits?
No. Directing and regenerating lines, voices, music and sound effects is included, until it's right.
Should I recast or change a single line?
Recast when you hear the character differently throughout the book. When one moment needs a different delivery, give Martin a note on that line instead, and the voice stays the same everywhere else.
