Chatterbox Multilingual: Open-Source Zero-Shot TTS with Emotion Controls and Watermarking
Overview
Resemble AI has published Chatterbox Multilingual, an open source production grade Text To Speech (TTS) model that supports zero-shot voice cloning across 23 languages. Distributed under the MIT license, the release extends the original Chatterbox framework with multilingual capability, expressive controls for delivery, and built-in PerTh watermarking for traceability.
Multilingual zero-shot voice cloning
Chatterbox Multilingual enables cloning of a speaker voice without retraining. By providing a short example audio sample, the model captures speaker characteristics and generates speech that matches that identity. Supported languages include Arabic, Hindi, Chinese, Swahili and many others, covering a broad range of linguistic families and use cases.
Expressive controls and intensity
Beyond basic voice identity, the model gives users control over emotion categories such as happy, sad, or angry, and an exaggeration parameter to scale intensity. This allows a single cloned voice to be adapted for upbeat narration, subdued prompts, or more dramatic delivery, which is useful for interactive media, dialog systems, gaming, and assistive technologies.
Watermarking and content traceability
Every generated file contains PerTh watermarking, a neural watermark technique developed by Resemble AI. The watermark is designed to be inaudible to listeners while remaining extractable via the provided open source detector. Embedding watermarking by default enables verification and traceability of synthetic audio, helping to mitigate misuse and support responsible deployment.
Performance compared with commercial systems
In blind A/B evaluations reported on Podonos, listeners showed a 63.75% preference for Chatterbox over ElevenLabs in the tested conditions. While some comparisons mention specific languages like German, the Podonos listener preference remains the only verifiable public metric cited. Overall, available evaluations suggest Chatterbox Multilingual is competitive with many commercial TTS offerings.
Deployment and hosted option
The open source release provides a baseline system that researchers, developers, and hobbyists can install and run under a permissive MIT license. For high concurrency, low latency, and enterprise compliance needs, Resemble AI offers Chatterbox Multilingual Pro, a managed hosted variant with sub 200 ms latency, fine tuned voices, SLAs, and additional compliance features suited to production workloads.
Why the open release matters
Chatterbox Multilingual contributes a controllable, multilingual voice cloning system to the speech synthesis ecosystem. By combining zero-shot cloning, expressivity controls, and mandatory watermarking in an accessible MIT licensed package, it provides a practical platform for further research, experimentation, and application development across academia and industry.
Resources
Official page: https://www.resemble.ai/chatterbox/
Check the GitHub Page for tutorials, example notebooks and integration guidance. Follow Resemble AI on social channels and join community forums for discussions and updates.