Miko voice for piper-plus (sample-voice-v1)

A small Japanese text-to-speech model that speaks as Miko, the official character of AITuber OnAir. It is a piper-plus VITS model fine-tuned from the multilingual zs-v1 base, exported to ONNX in FP16 so it runs in the browser with WebAssembly.

The voice is synthetic. The training audio was generated with Irodori-TTS from a designed voice; no person was recorded.

Files

• Sample rate: 22,050 Hz, mono
• Inputs: input, input_lengths, scales, lid, prosody_features
• Language id: ja = 0 (the model is based on a six-language table but was fine-tuned on Japanese only)
• Suggested length_scale: 1.1 (slightly slower than the model's native pace)

Usage

With @aituber-onair/voice 0.27.0 or later, which builds the padded phoneme sequence this model expects:

import { PiperPlusEngine } from '@aituber-onair/voice';

const engine = new PiperPlusEngine();
engine.setAssets({
  basePath: '/piper/', // piper-plus web runtime + OpenJTalk dictionary
  modelConfigFile: 'sample-voice-v1.onnx.json',
  modelFile: 'sample-voice-v1.onnx',
  voiceFile: 'mei_normal.htsvoice',
});
engine.setSpeed(0.9);
engine.setNoiseScale(0.667);
const wav = await engine.fetchAudio({ style: 'talk', message: 'こんにちは' }, '');

The piper-plus web runtime (npm install piper-plus) can load the same files through its multilingual code path.

Training

• Base: piper-plus zs-v1 (ayousanz/piper-plus-base, releases/zs-v1)
• Fine-tuned as a single speaker on about 0.8 hours of synthetic Japanese speech (734 sentences: original sentences plus the public-domain ITA corpus)
• 300 epochs, duration predictor frozen; exported with piper-plus 2.0.0

License and notices

• Model weights: MIT, following the base model. See BASE_MODEL_LICENSE.txt and BASE_MODEL_NOTICE.md for the base model's provenance, including the datasets its authors used.
• Miko is the character of AITuber OnAir, © Yuki Shindo. Use of the character follows the Miko Character Usage Guidelines.
• Do not present output from this model as a recording of a real person.