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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. Add a NobodyWhoTts node to your scene, then use it from a script:

extends Node

@onready var tts: NobodyWhoTts = $NobodyWhoTts

func _ready():
    tts.source = "NobodyWho/Kokoro-82M" # Hugging Face repo ID or local folder with the model files.
    tts.voice = "bf_emma" # Voice to use from the model.
    tts.language = "en-gb" # Language code for the input text.

    tts.start_worker()
    await tts.worker_started

    # Generate WAV bytes for this sentence.
    var result: Dictionary = await tts.synthesize("Hello from NobodyWho!")
    if not result.ok:
        push_error(result.error)
        return

    # Save the audio to a file.
    var file = FileAccess.open("user://out.wav", FileAccess.WRITE)
    file.store_buffer(result.wav)

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.

tts.source = "NobodyWho/Kokoro-82M"
tts.voice = "bf_emma"
tts.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. Set 0 to use the backend default.

Supertonic​

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

tts.source = "Supertone/supertonic-3"
tts.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. Set 0 to use the backend default.
  • steps: denoising steps. Higher values can improve quality but are slower. Lower values are faster but can sound rougher. Set 0 to use the backend default.
  • silence_duration: seconds of silence between long text chunks. Higher values add longer pauses. Set -1 to use the backend default.

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, Godot path, or a custom source that NobodyWho cannot recognize:

tts.source = "res://models/kokoro-folder"
tts.backend = "kokoro"

Supported backend values are kokoro and supertonic.

GPU​

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

tts.source = "Supertone/supertonic-3"
tts.device = "cpu"
tts.start_worker()

Local model folder format​

When source is a local directory or Godot path, point it at the top-level model folder and set 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.