Audio8 TTS 0.1B supports speech generation and zero-shot voice cloning. This
repository contains the complete v4 mixed checkpoint, its neural audio codec,
tokenizer, processor, and Hugging Face remote code.
Compact Scale
The defining characteristic of this release is its size. The main generative
model is approximately 170M parameters, while the codec decoder is a
separate approximately 120M-parameter component. Even counting the codec
decoder, the complete audio generation stack remains much smaller than most
modern multilingual TTS systems.
Model
Reported main-model scale
Audio8 TTS Preview 0.1B
~0.17B
Audio8 TTS Preview 0.6B
~0.6B
IndexTTS2.5
~0.8B
CosyVoice3
~1.5B
VoxCPM2
~2.3B
Fish S2 Pro
~4.6B
Higgs Audio v2
~4.7B
MOSS-TTS
~8.5B
These figures are approximate reference scales collected from the respective
model reports and are not a strictly matched parameter-count audit. The 0.1B
checkpoint is intended to make zero-shot TTS practical with a much smaller
language/audio model footprint, not to claim identical quality across every
language or benchmark.
Supported Languages
Primary: Chinese and English
Experimental/multilingual evaluation: German, Spanish, French, Italian,
Japanese, and Korean
Model Details
The model uses an Audio8 Falcon H1 architecture with slow and fast autoregressive
branches. The slow branch predicts semantic tokens, while the fast branch
predicts codec codebooks conditioned on the slow hidden state.
Component
Configuration
Main model
Approximately 170M parameters, excluding the codec decoder
44.1 kHz, 2,048 samples per model frame (~21.5 frames/s)
Codec decoder
Approximately 120M parameters; bundled in codec.pth
Context
Up to 2,048 packed text/audio positions
The codec is included in this repository. No additional codec checkpoint is
required.
Deployment Options
CPU deployment: ONNX INT8
Audio8-TTS-Preview-0.1B-ONNX-INT8
packages Audio8 TTS for low-resource CPU inference with ONNX Runtime. Slow and
Fast AR use per-token INT8 graphs, while the neural audio codec uses FP16.
Advantage
Details
CPU native
Runs with ONNX Runtime CPUExecutionProvider; no CUDA required
Low memory
About 0.4 GiB after loading in the tested Linux x86_64 configuration
Small runtime
No PyTorch or Transformers dependency after model download
Complete workflow
CLI, web and HTTP service, streaming PCM, and voice registration
Normal synthesis loads only the Slow AR, Fast AR, and codec decoder sessions.
Voice registration releases those sessions before loading the optional codec
encoder, keeping peak memory controlled.
The model includes custom Transformers code. Load it with
trust_remote_code=True.
Voice cloning
The primary usage of this checkpoint is zero-shot voice cloning. Replace
reference.wav and the reference transcript with your own audio and text. The
reference transcript should match the spoken content of the reference audio.
For synthesis without cloning, omit reference_audio and reference_text.
For batch inference with audio or pre-encoded reference codes, see the Audio8
TTS training and inference repository.
Evaluation
Lower WER/CER is better; higher SIM (similarity) is better.
CV3 error-rate comparison
Lower is better. These comparison values follow the evaluation table published
for Audio8 TTS Preview 0.6B; they are reference comparisons rather than a
strictly matched re-evaluation.
Model
Parameters
zh
en
ja
ko
de
es
fr
it
Audio8 TTS Preview 0.1B
~0.17B
3.619
3.307
12.322
7.653
5.292
8.548
12.349
14.480
Audio8 TTS Preview 0.6B
0.6B
3.205
3.128
7.205
4.223
3.447
3.641
8.790
4.790
Fish S2 Pro
4.6B
3.600
3.493
5.139
4.111
3.605
2.972
8.600
4.229
Higgs Audio v2
4.7B
3.378
3.404
4.742
4.260
3.300
2.929
9.425
3.555
CosyVoice3-1.5B
1.5B
3.91
4.99
7.57
5.69
6.43
4.47
11.8
10.5
VoxCPM2
2.3B
3.65
5.00
5.96
5.69
4.77
3.80
9.85
4.25
IndexTTS2.5
0.8B
4.36
5.12
5.66
-
-
3.75
-
-
Seed-TTS comparison
Similarity values are shown as percentages in this comparison table. Lower
WER/CER is better; higher similarity is better.
Model
Parameters
EN WER / SIM
ZH CER / SIM
Audio8 TTS Preview 0.1B
~0.17B
1.662 / 56.7
1.13 / 68.2
Audio8 TTS Preview 0.6B
0.6B
1.506 / 63.2
0.950 / 73.1
Fish S2 Pro
4.6B
1.607 / 64.6
1.038 / 73.8
Higgs Audio v2
4.7B
1.524 / 66.4
0.806 / 72.1
CosyVoice3-1.5B
1.5B
2.22 / 72.0
1.12 / 78.1
MOSS-TTS
8.5B
1.85 / 73.4
1.20 / 78.8
VoxCPM2
2.3B
1.84 / 75.3
0.97 / 79.5
IndexTTS2.5
0.8B
3.253 / 82.3
1.119 / 80.4
The IndexTTS2.5 row uses the Token-Level Concatenation result from the
Seed-TTS-Eval portion of Table 1 in the IndexTTS 2.5 technical report.
Parameter scales are approximate reference values from the respective model
reports (see the Compact Scale section); they are not a strictly matched
parameter-count audit. For reference, MOSS-TTS contains 8,489,841,664
parameters and VoxCPM2's main model contains 2,290,004,544 parameters; the
separate AudioVAE is not included in the parameter comparison.
Fish S2 Pro was reevaluated because its official evaluation uses its own
normalizer. Higgs Audio v2 was evaluated locally because concrete values were
unavailable. All other baseline values were collected from their official
reports through the VoxCPM repository.
Different normalizers and evaluators make cross-project values reference
comparisons rather than a strictly matched ranking. Evaluation coverage does
not expand the Preview checkpoint's supported-language claim beyond the
languages listed above.
Limitations and Responsible Use
This is a compact preview checkpoint. Chinese and English are the primary
target languages; other languages generally show weaker and more variable
quality.
Very long, noisy, or incorrectly transcribed reference clips can reduce
generation stability and speaker similarity.
Generated speech can be misused for impersonation or misinformation. Obtain
consent before cloning a voice and disclose synthetic audio where appropriate.
Evaluate the model for accuracy, safety, and legal compliance before
deployment.
Non-Commercial Use (research, personal, educational, evaluation) is free.
Commercial Use is free for entities whose annual revenue (including
parent companies, subsidiaries, and affiliates) is less than US$2,000,000.
Entities with annual revenue of US$2,000,000 or more must obtain a
separate written commercial license from Audio8 before any Commercial Use.
English text is authoritative; a Chinese translation is provided in the
LICENSE file for reference. For commercial licenses, contact the Audio8 team
via the Audio8 GitHub repository or
an issue on this Hugging Face repository.