# Amazon's Audible team uses controllable TTS to voice audiobook characters

> Original title: Better speech synthesis for audiobooks

- Source: Amazon Science
- Published: 2026-10-23T15:20:02.000Z
- Bad Influence: https://badinfluence.news/items/jbjkn9iuv8dvgd7p4ywzh0rnj
- Original: https://www.amazon.science/blog/better-speech-synthesis-for-audiobooks

## Summary

Audible's technology team is using controllable text-to-speech to give audiobook characters distinct voices, with its BookLLM component identifying speakers at 97% accuracy in English and 94% in Spanish. The approach improved dialogue differentiation by 3.7 points on a MUSHRA test, and listeners preferred the new audio for eight of ten voices in statistically significant tests across English and Spanish.