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Text-to-speech

NobodyWho can generate audio from any piece of text, in a wide variety of languages. You pass in text and get WAV bytes back, ready to save or play in your app. This process is also known as Text-to-Speech (or TTS).

Quick start​

Here's how you get started:

import { Tts } from "react-native-nobodywho";

const tts = await Tts.load({
  source: "NobodyWho/Kokoro-82M", // Hugging Face repo ID or local folder with the model files.
  voice: "bf_emma", // Voice to use from the model.
  language: "en-gb", // Language code for the input text.
});

// Generate WAV bytes for this sentence.
const wav = await tts.synthesize("Hello from NobodyWho!");
// wav is a Uint8Array containing WAV bytes.

Let’s start with source: it tells NobodyWho which TTS model to load. More on that in the next section.

Models and sources​

NobodyWho currently supports two main model sources:

Kokoro​

For Kokoro, set voice and language together. They must agree with the model's available voices.

const tts = await Tts.load({
  source: "NobodyWho/Kokoro-82M",
  voice: "bf_emma",
  language: "en-gb",
});

Optional settings include:

  • voice: voice to use from the model, e.g. bf_emma. See the Kokoro voices folder for the full list. Defaults to bf_emma.
  • language: input language code. Supported values are listed on the Kokoro model page. Defaults to en-gb.
  • speed: speech speed multiplier. 1.0 is normal speed, lower values are slower, higher values are faster. Defaults to 1.0.

Supertonic​

For Supertonic, you can start with the default voice and language, or set them explicitly.

const tts = await Tts.load({
  source: "Supertone/supertonic-3",
  language: "en",
});

Optional settings include:

  • voice: voice style. Supported values are M1 to M5 and F1 to F5. Defaults to M1.
  • language: input language code. See the Supertonic model page for the full list. Defaults to en.
  • speed: speech speed multiplier. 1.0 is normal speed, lower values are slower, higher values are faster. Defaults to 1.05.
  • steps: denoising steps. Higher values can improve quality but are slower. Lower values are faster but can sound rougher. Must be greater than 0; defaults to 8.
  • silenceDuration: seconds of silence between long text chunks. Higher values add longer pauses. Must be 0 or higher; defaults to 0.3.

Backend​

backend is the TTS engine/model family behind a source. In most cases, you do not need to set it because NobodyWho can infer it from source.

Set backend when you use a local directory or a custom source that NobodyWho cannot recognize:

const tts = await Tts.load({
  source: "/path/to/local/kokoro-folder",
  backend: "kokoro",
});

Supported backend values are kokoro and supertonic.

GPU​

TTS uses GPU acceleration by default when available. Disable it with device: "cpu":

const tts = await Tts.load({
  source: "Supertone/supertonic-3",
  device: "cpu",
});

Local model folder format​

When source is a local directory, point it at the top-level model folder and pass the matching backend.

Use the Hugging Face file browsers as the reference layouts:

For Supertonic, that top-level folder must include both the onnx/ and voice_styles/ directories. Download the model files with the same relative paths, then pass that folder as source.