Gradium details Phonon on-device text-to-speech models with open weights

Gradium published a closer look at Phonon, its small text-to-speech model that runs on a local device with no server or network connection. Two checkpoints of roughly 65 MB and 75 MB cover English, French, German, Spanish and Portuguese, with more than 100 built-in voices plus voice cloning and text-described voices in Gradium Studio. The English 31m model is Apache 2.0 and usable in commercial products; the multilingual 40m model is CC BY-NC for non-commercial work. Phonon ships in Transformers from v5.21 and through ptts, a new inference framework with CPU, GPU and NPU backends. On Hugging Face's Open TTS Leaderboard it placed first for German and Spanish intelligibility and in the top three for every language the company evaluated.