AuK-Flash: Fast 4-Step Speech Generation and Editing

News

• [2026/09/09] 🎉 AuK is now open-source. Code and model weights are publicly available. Try it on the 🤗 Demo Space or the 🤖 ModelScope Space!

Contents

• News
• Introduction
• Performance
• Model Architecture
• Supported Tasks
• Download the weights
• Citation
• License

Introduction

AuK is a 1.5B foundation model for speech generation and editing. Trained on millions of hours of diverse audio data, AuK supports zero-shot and instruction-based TTS, content and acoustic editing, paralinguistic editing, speech enhancement, and source separation through a unified natural-language instruction interface. AuK has two variants:

Model	Description	Weight
AuK	Base model for high-quality generation	🤗 Hugging Face · 🤖 ModelScope
AuK-Flash	Distilled model for fast 4-step inference	🤗 Hugging Face · 🤖 ModelScope

This repository contains the official weights for AuK-Flash, the distilled variant with fast 4-step inference.

Performance

Model Architecture

Supported Tasks

AuK exposes every task through the same natural-language instruction interface. The table below groups the supported tasks by category, with a short description and a link to its section in the Cookbook, which provides instruction templates plus CLI and Python examples.

Category	Task	Description	Cookbook
Speech Generation	Zero-shot TTS	Speak the target text in the voice of the reference audio.	Zero-shot TTS
	Instruct TTS	Generate speech from a voice description alone — no reference audio.	Instruct TTS
Content Editing	Speech Content Editing	Rewrite what is said — replace, insert, or remove text.	Speech Content Editing
	Lyric Editing	Rewrite lyrics in a singing recording while preserving the melody and voice.	Lyric Editing
Acoustic Editing	Pitch Editing	Raise or lower the pitch by semitones.	Pitch Editing
	Speed Editing	Adjust the speaking rate; output length scales with the speed factor.	Speed Editing
	Volume Editing	Raise or lower the volume by decibels.	Volume Editing
Paralinguistic Editing	Emotion	Change the emotion while preserving content and voice.	Emotion
	Timbre	Change the timbre to a description while keeping the content unchanged.	Timbre
	De-accent	Remove a regional accent while preserving the speaker's voice and content.	De-accent
	Nonverbal Editing	Remove or add nonverbal sounds such as breaths, laughs, or coughs.	Nonverbal Editing
	Whisper Conversion	Convert between normal speech and whisper while preserving speaker and content.	Whisper Conversion
Enhancement & Separation	Speech Enhancement	Denoise, dereverberate, or restore natural, clear speech.	Speech Enhancement
	Speech Separation	Keep one speaker by talking order and remove the others.	Speech Separation
	Music Separation	Extract the singing voice from a mix, or keep all human voices.	Music Separation
	Target Speaker Extraction	Keep the target speaker identified by what they say.	Target Speaker Extraction

Download the weights

🤗 HuggingFace

pip install -U "huggingface_hub[cli]"

# AuK-Base
hf download tencent/AuK --local-dir ./ckpts/AuK

# AuK-Flash (4-step distilled) 
hf download tencent/AuK-Flash --local-dir ./ckpts/AuK-Flash

# MLLM Encoder
hf download Qwen/Qwen2.5-Omni-3B  --local-dir ./ckpts/Qwen2.5-Omni-3B

🤖 ModelScope

pip install -U modelscope

# AuK-Base
modelscope download --model Tencent-Hunyuan/AuK --local_dir ./ckpts/AuK

# AuK-Flash (4-step distilled)
modelscope download --model Tencent-Hunyuan/AuK-Flash  --local_dir ./ckpts/AuK-Flash

# MLLM Encoder
modelscope download --model Qwen/Qwen2.5-Omni-3B --local_dir ./ckpts/Qwen2.5-Omni-3B

The expected directory structure is:

ckpts/
├── AuK/
├── AuK-Flash/          # optional
└── Qwen2.5-Omni-3B/

The model checkpoint contains the diffusion transformer and layer-fusion weights. The MLLM encoder and VAE are loaded from separate files at runtime, so missing text_encoder.* keys during checkpoint loading are expected.

For installation, inference, Gradio, ComfyUI, and fine-tuning, see the GitHub README and Cookbook.

Citation

Research using AuK can cite the following entry:

@misc{ma2026auktechnicalreportopensource,
  title={AuK Technical Report: An Open-Source Foundational Model for Speech Generation and Editing},
  author={Ziyang Ma and Zhikang Niu and Wenming Tu and Tianrui Wang and Ruiqi Yan and Junxi Liu and Yanru Huo and Nickk Huang and Yang Liu and Qicong Xie and Zeyu Xie and Hui Wang and Haitao Li and Zixuan Jiang and Yalin Li and Jie Fang and Yifan Duan and Zeyue Tian and Guangzheng Li and Haina Zhu and Shuyi Wang and Jinwen Wang and Mingyu Cui and Tian Tan and Auden and Sen Liang and Steve Yves and Shan Yang and Liefeng Bo and Zilong Zheng and Kai Yu and Eng-Siong Chng and Xie Chen},
  year={2026},
  eprint={2609.08936},
  archivePrefix={arXiv},
  primaryClass={cs.SD},
  url={https://arxiv.org/abs/2609.08936},
}

License

AuK is released under the MIT License. See LICENSE for the full terms.