--- license: apache-2.0 language: - en - zh tags: - audio - speech - music - understanding - multimodal - instruct pipeline_tag: audio-text-to-text --- # MOSS-Audio

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MOSS-Audio is an open-source **audio understanding model** from [MOSI.AI](https://mosi.cn/#hero), the [OpenMOSS team](https://www.open-moss.com/), and [Shanghai Innovation Institute](https://www.sii.edu.cn/). It performs unified modeling over complex real-world audio, supporting **speech understanding, environmental sound understanding, music understanding, audio captioning, time-aware QA, and complex reasoning**. In this release, we provide **four models**: **MOSS-Audio-4B-Instruct**, **MOSS-Audio-4B-Thinking**, **MOSS-Audio-8B-Instruct**, and **MOSS-Audio-8B-Thinking**. The Instruct variants are optimized for direct instruction following, while the Thinking variants provide stronger chain-of-thought reasoning capabilities. ## News * 2026.4.13: 🎉🎉🎉 We have released [MOSS-Audio](https://huggingface.co/collections/OpenMOSS-Team/moss-audio). Blog and paper coming soon! ## Contents - [Introduction](#introduction) - [Model Architecture](#model-architecture) - [DeepStack Cross-Layer Feature Injection](#deepstack-cross-layer-feature-injection) - [Time-Aware Representation](#time-aware-representation) - [Released Models](#released-models) - [Evaluation](#evaluation) - [Quickstart](#quickstart) - [Environment Setup](#environment-setup) - [Basic Usage](#basic-usage) - [Gradio App](#gradio-app) - [SGLang Serving](#sglang-serving) - [More Information](#more-information) - [Citation](#citation) ## Introduction

Understanding audio requires more than simply transcribing words — it demands the ability to perceive acoustic cues, recognize speakers and emotions, interpret environmental sounds, reason over temporal context, and handle complex multi-step inference. **MOSS-Audio** is built to unify these capabilities within a single model. - **Speech & Content Understanding**: Accurately recognizes and transcribes spoken content from audio inputs, producing clean and well-structured text outputs. Supports both word-level and sentence-level timestamp alignment. - **Speaker, Emotion & Event Analysis**: Identifies speaker characteristics, analyzes emotional states based on tone, timbre, and context, and detects key acoustic events within the audio. - **Scene & Sound Cue Extraction**: Extracts meaningful cues from background sounds, environmental noise, music, and non-speech signals to infer scene context and atmosphere. - **Music Understanding**: Analyzes musical style, emotional progression, instrumentation, and salient acoustic features in music segments. - **Audio Question Answering & Summarization**: Answers questions and generates summaries about speech, podcasts, meetings, interviews, and environmental recordings, helping users efficiently extract key information. - **Time-Aware QA**: Supports time-aware questions, including word-level and sentence-level timestamp ASR. - **Complex Reasoning**: Performs multi-hop reasoning over audio content, powered by chain-of-thought training and reinforcement learning. ## Model Architecture

MOSS-Audio follows a modular design comprising three components: an audio encoder, a modality adapter, and a large language model. Raw audio is first encoded by **MOSS-Audio-Encoder** into continuous temporal representations at **12.5 Hz**, which are then projected into the language model's embedding space through the adapter and finally consumed by the LLM for auto-regressive text generation. Rather than relying on off-the-shelf audio frontends, we train a dedicated encoder from scratch to obtain more robust speech representations, tighter temporal alignment, and better extensibility across acoustic domains. ### DeepStack Cross-Layer Feature Injection Using only the encoder's top-layer features tends to lose low-level prosody, transient events, and local time-frequency structure. To address this, we design a **DeepStack**-inspired cross-layer injection module between the encoder and the language model: in addition to the encoder's final-layer output, features from earlier and intermediate layers are selected, independently projected, and injected into the language model's early layers, preserving multi-granularity information from low-level acoustic details to high-level semantic abstractions. This design is especially well-suited for audio understanding tasks, as it helps retain rhythm, timbre, transients, and background structure — information that a single high-level representation cannot fully capture. ### Time-Aware Representation Time is a critical dimension in audio understanding. To enhance explicit temporal awareness, we adopt a **time-marker insertion** strategy during pretraining: explicit time tokens are inserted between audio frame representations at fixed time intervals to indicate temporal positions. This design enables the model to learn "what happened when" within a unified text generation framework, naturally supporting timestamp ASR, event localization, time-based QA, and long-audio retrospection. ## Released Models | Model | Audio Encoder | LLM Backbone | Total Size | Hugging Face | |---|---|---|---:|---| | **MOSS-Audio-4B-Instruct** | MOSS-Audio-Encoder | Qwen3-4B | ~4.6B | [![Hugging Face](https://img.shields.io/badge/Huggingface-Model-orange?logo=huggingface)](https://huggingface.co/OpenMOSS-Team/MOSS-Audio-4B-Instruct) | **MOSS-Audio-4B-Thinking** | MOSS-Audio-Encoder | Qwen3-4B | ~4.6B | [![Hugging Face](https://img.shields.io/badge/Huggingface-Model-orange?logo=huggingface)](https://huggingface.co/OpenMOSS-Team/MOSS-Audio-4B-Thinking) | **MOSS-Audio-8B-Instruct** | MOSS-Audio-Encoder | Qwen3-8B | ~8.6B | [![Hugging Face](https://img.shields.io/badge/Huggingface-Model-orange?logo=huggingface)](https://huggingface.co/OpenMOSS-Team/MOSS-Audio-8B-Instruct) | **MOSS-Audio-8B-Thinking** | MOSS-Audio-Encoder | Qwen3-8B | ~8.6B | [![Hugging Face](https://img.shields.io/badge/Huggingface-Model-orange?logo=huggingface)](https://huggingface.co/OpenMOSS-Team/MOSS-Audio-8B-Thinking) > More model families, sizes, and variants will be released in the future. Stay tuned! ## Evaluation We evaluate MOSS-Audio on a comprehensive set of audio understanding benchmarks. Key results: - **General Audio Understanding**: MOSS-Audio-8B-Thinking achieves an average accuracy of **70.80**, outperforming all of the open-source models. - **Speech Captioning**: MOSS-Audio-Instruct variants lead across **11 out of 13** fine-grained speech description dimensions, with **MOSS-Audio-8B-Instruct** achieving the best overall average score (**3.7252**). - **ASR**: On a diverse ASR benchmark suite spanning 12 evaluation dimensions, MOSS-Audio achieves the **lowest overall CER (11.30)**, with particular strength in health-condition, code-switching, dialect, singing, and non-speech scenarios. - **Timestamp ASR**: MOSS-Audio-8B-Instruct achieves **35.77 AAS** on AISHELL-1 and **131.61 AAS** on LibriSpeech, dramatically outperforming Qwen3-Omni (833.66) and Gemini-3.1-Pro (708.24) in timestamp asr accuracy. ### General Audio Understanding (Accuracy↑)

Model Model Size MMAU MMAU-Pro MMAR MMSU Avg
Open Source (small)
Kimi-Audio7B72.4156.5860.8254.7461.14
Qwen2.5-Omni7B65.6052.2056.7061.3258.96
Audio Flamingo 37B61.2351.7057.9660.0457.73
MiMo-Audio-7B7B74.9053.3561.7061.9462.97
MiniCPM-o-4.59B70.9739.6555.7560.9656.83
MOSS-Audio-4B-Instruct4B75.7958.1659.6859.6864.04
MOSS-Audio-4B-Thinking4B77.6460.7563.9171.2068.37
MOSS-Audio-8B-Instruct8B77.0357.4864.4266.3666.32
MOSS-Audio-8B-Thinking8B77.1364.2965.7376.0670.80
Open Source (large)
Qwen3-Omni-30B-A3B-Instruct30B75.0061.2266.4069.0067.91
Step-Audio-R1.133B72.1860.8068.7564.1866.48
Step-Audio-R133B78.6759.6869.1575.1870.67
Closed Source
GPT4o-Audio-65.6652.3059.7858.7659.13
Gemini-3-Pro-80.1568.2881.7381.2877.86
Gemini-3.1-Pro-81.1073.4783.7081.3079.89
### Speech Captioning (LLM-as-a-Judge Score↑)

Speech Captioning (click to expand) | Model | gender | age | accent | pitch | volume | speed | texture | clarity | fluency | emotion | tone | personality | summary | Avg | |---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:| | Qwen3-Omni-30B-A3B-Instruct | 4.436 | 3.936 | 4.356 | 3.590 | 3.682 | 3.614 | 3.093 | 3.521 | 3.531 | 3.328 | 3.224 | 3.292 | 3.179 | 3.5986 | | Qwen3-Omni-30B-A3B-Thinking | 4.419 | **4.026** | 4.327 | 3.610 | 3.577 | 3.610 | 3.179 | 3.403 | 3.526 | 3.232 | 3.154 | 3.197 | 3.107 | 3.5667 | | Gemini-3-Pro | 4.191 | 3.835 | 4.181 | 3.392 | 3.254 | 3.320 | 2.998 | 3.347 | 3.524 | 3.055 | 2.997 | 3.023 | 2.775 | 3.3763 | | Gemini-3.1-Pro| 4.436 | 3.936 | 4.356 | 3.590 | 3.682 | 3.614 | 3.093 | 3.521 | 3.531 | **3.328** | 3.224 | 3.292 | 3.179 | 3.5986 | | MOSS-Audio-4B-Instruct | **4.697** | 3.980 | 4.497 | 3.628 | **3.722** | 3.564 | **3.407** | 3.841 | 3.744 | 3.311 | **3.282** | **3.305** | 3.259 | 3.7105 | | MOSS-Audio-8B-Instruct | 4.683 | 3.979 | **4.572** | **3.682** | 3.709 | **3.638** | 3.403 | **3.869** | **3.747** | 3.314 | 3.253 | 3.272 | **3.307** | **3.7252** |
### ASR | Model | Overall | Health Condition | Dialect | Singing | Non-Speech Vocalizations | Code-Switching | Acoustic Environment (Clean) | Acoustic Environment (Noisy) | Acoustic Characteristics: Whisper | Acoustic Characteristics: Far-Field / Near-Field | Multi-Speaker | Age | Semantic Content | |---|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:|---:| | Paraformer-Large | 15.77 | 22.18 | 43.45 | 32.34 | 4.95 | 12.65 | 3.11 | 4.67 | 5.02 | 17.46 | 20.33 | 14.96 | 7.14 | | GLM-ASR-Nano | 17.29 | 24.49 | 22.39 | 51.95 | 4.65 | 11.88 | 3.68 | 5.02 | 4.94 | 27.51 | 28.02 | 17.19 | 7.32 | | Fun-ASR-Nano | 12.04 | 21.99 | 7.80 | 19.35 | 4.76 | 11.23 | 2.98 | 3.46 | 3.78 | 18.38 | 19.82 | **14.95** | 6.08 | | SenseVoice-Small | 14.50 | 24.04 | 8.89 | 23.79 | 4.92 | 13.90 | 4.13 | 4.93 | 5.57 | 26.66 | 24.06 | 17.63 | 7.55 | | Kimi-Audio-7B-Instruct | 14.12 | 21.11 | 29.34 | 21.76 | 4.68 | 16.38 | **2.20** | **2.15** | 2.66 | 21.02 | 20.61 | 16.74 | 6.12 | | Qwen2.5-Omni-3B | 15.26 | 24.65 | 33.87 | 24.24 | 5.54 | 11.66 | 2.76 | 3.56 | 4.32 | 22.15 | 22.91 | 15.17 | 7.24 | | Qwen2.5-Omni-7B | 15.05 | 23.85 | 31.91 | 22.69 | 4.56 | 12.97 | 2.52 | 3.16 | 3.64 | 25.38 | 21.01 | 16.13 | 6.78 | | Qwen3-Omni-30B-A3B-Instruct | 11.39 | 20.73 | 15.63 | 16.01 | 4.73 | 11.30 | 2.23 | 2.47 | **1.90** | **17.08** | **18.15** | **11.46** | **5.74** | | **MOSS-Audio-4B-Instruct** | 11.58 | 21.11 | 11.84 | 10.79 | **4.01** | **10.11** | 3.11 | 3.72 | 3.29 | 18.48 | 20.33 | 15.09 | 8.15 | | **MOSS-Audio-8B-Instruct** | **11.30** | **19.18** | **8.76** | **9.81** | 4.31 | 10.18 | 2.70 | 3.20 | 2.75 | 24.04 | 24.36 | 15.26 | 7.69 |
Detailed ASR Results (click to expand)
Model Acoustic Environment (Clean) Acoustic Environment (Noisy) Acoustic Characteristics: Whisper Acoustic Characteristics: Far-Field / Near-Field Multi-Speaker Age Health Condition Semantic Content Code-Switching Dialect Singing Non-Speech Vocalizations
AISHELL-1
test
AISHELL-2
Android | IOS | Mic
THCHS-30
test
MAGICDATA-READ
test
AISHELL6-Whisper
normal | whisper
AliMeeting
Test_Ali_far | Test_Ali_near
AISHELL-4
test
SeniorTalk
sentence
ChildMandarin
test
AISHELL-6A
mild | moderate | severe | StutteringSpeech
AISHELL_6B
LRDWWS | Uncontrol
WenetSpeech
test-meeting
Fleurs
cmn_hans_cn
CS-Dialogue
test
TALCS
test
ASCEND
test
KeSpeech
test
WSYue-ASR-eval
short
MIR-1K
test
openc-pop
test
MNV_17
Paraformer-Large 1.98 3.28 | 3.21 | 3.00 4.07 4.67 1.11 | 8.92 25.64 | 9.27 20.33 17.31 12.60 6.98 | 9.30 | 13.34 | 10.74 47.59 | 45.08 7.88 6.40 10.64 10.77 16.55 11.48 75.42 57.70 6.98 4.95
GLM-ASR-Nano 2.89 3.75 | 3.73 | 3.78 4.23 5.02 0.83 | 9.06 40.27 | 14.76 28.02 20.33 14.06 8.74 | 12.11 | 14.38 | 12.29 50.34 | 49.09 9.70 4.94 11.06 11.07 13.50 9.72 35.07 95.87 8.03 4.65
Fun-ASR-Nano 2.16 3.04 | 2.99 | 3.07 3.65 3.46 0.81 | 6.76 27.21 | 9.55 19.82 16.96 12.94 6.60 | 8.81 | 12.98 | 10.30 47.42 | 45.84 7.39 4.76 10.47 8.09 15.13 7.43 8.17 35.85 2.84 4.76
SenseVoice-Small 3.23 4.16 | 4.02 | 3.96 5.26 4.93 1.25 | 9.88 37.01 | 16.31 24.06 21.07 14.18 7.62 | 9.85 | 14.39 | 11.47 52.92 | 47.97 8.35 6.75 12.81 10.52 18.38 10.45 7.34 39.51 8.07 4.92
Kimi-Audio-7B-Instruct 0.79 2.91 | 3.03 | 2.88 1.39 2.15 0.69 | 4.63 28.22 | 13.82 20.61 19.70 13.79 7.00 | 9.34 | 12.56 | 10.75 44.44 | 42.57 7.15 5.10 14.56 12.74 21.83 5.51 53.17 38.35 5.17 4.68
Qwen2.5-Omni-3B 1.51 3.10 | 2.94 | 2.93 3.32 3.56 0.82 | 7.82 32.14 | 12.16 22.91 17.38 12.96 6.87 | 10.55 | 14.57 | 11.33 54.54 | 50.03 9.04 5.45 10.78 10.94 13.25 7.67 60.06 45.00 3.47 5.54
Qwen2.5-Omni-7B 1.16 2.88 | 2.77 | 2.73 3.06 3.16 0.71 | 6.57 32.03 | 18.73 21.01 19.96 12.29 7.27 | 10.94 | 12.92 | 10.53 51.99 | 49.45 8.43 5.13 14.02 10.46 14.42 6.40 57.43 42.62 2.75 4.56
Qwen3-Omni-30B-A3B-Instruct 0.95 2.70 | 2.72 | 2.57 2.21 2.47 0.59 | 3.22 25.72 | 8.44 18.15 14.13 8.79 6.20 | 8.88 | 11.59 | 10.25 45.80 | 41.65 6.64 4.84 12.94 8.33 12.64 5.87 25.39 30.81 1.21 4.73
MOSS-Audio-4B-Instruct 2.26 3.22 | 3.20 | 3.33 3.53 3.72 0.73 | 5.86 27.27 | 9.68 20.33 16.93 13.25 6.36 | 9.77 | 12.68 | 10.28 43.35 | 44.25 8.17 8.13 9.14 8.37 12.83 14.65 9.04 18.47 3.10 4.01
MOSS-Audio-8B-Instruct 1.82 2.97 | 2.95 | 2.91 2.82 3.20 0.69 | 4.80 36.82 | 11.25 24.36 17.42 13.10 5.84 | 8.94 | 11.52 | 9.72 39.76 | 39.27 7.86 7.52 9.07 8.22 13.26 9.18 8.33 17.24 2.39 4.31
### Timestamp ASR (AAS↓) | Model | AISHELL-1(zh) | LibriSpeech(en) | |---|---:|---:| | Qwen3-Omni-30B-A3B-Instruct | 833.66 | 646.95 | | Gemini-3.1-Pro| 708.24 | 871.19 | | MOSS-Audio-4B-Instruct | 76.96 | 358.13 | | **MOSS-Audio-8B-Instruct** | **35.77** | **131.61** | ## Quickstart ### Environment Setup We recommend Python 3.12 with a clean Conda environment. The commands below are enough for local inference. #### Recommended setup ```bash git clone https://github.com/OpenMOSS/MOSS-Audio.git cd MOSS-Audio conda create -n moss-audio python=3.12 -y conda activate moss-audio conda install -c conda-forge "ffmpeg=7" -y pip install --extra-index-url https://download.pytorch.org/whl/cu128 -e ".[torch-runtime]" ``` #### Optional: FlashAttention 2 If your GPU supports FlashAttention 2, you can replace the last install command with: ```bash pip install --extra-index-url https://download.pytorch.org/whl/cu128 -e ".[torch-runtime,flash-attn]" ``` ### Basic Usage Download the model first: ```bash huggingface-cli download OpenMOSS-Team/MOSS-Audio --local-dir ./weights/MOSS-Audio huggingface-cli download OpenMOSS-Team/MOSS-Audio-Instruct --local-dir ./weights/MOSS-Audio-Instruct ``` Then edit `MODEL_PATH` / `AUDIO_PATH` in `infer.py` as needed, and run: ```bash python infer.py ``` The default prompt in `infer.py` is `Describe this audio.` You can directly edit that line if you want to try transcription, audio QA, or speech captioning. ### Gradio App Start the Gradio demo with: ```bash python app.py ``` ### SGLang Serving If you want to serve MOSS-Audio with SGLang, see the full guide in `moss_audio_usage_guide.md`. The shortest setup is: ```bash git clone -b moss-audio https://github.com/OpenMOSS/sglang.git cd sglang pip install -e "python[all]" pip install nvidia-cudnn-cu12==9.16.0.29 cd .. sglang serve --model-path ./weights/MOSS-Audio --trust-remote-code ``` If you use the default `torch==2.9.1+cu128` runtime, installing `nvidia-cudnn-cu12==9.16.0.29` is recommended before starting `sglang serve`. ## More Information - **MOSI.AI**: [https://mosi.cn](https://mosi.cn) - **OpenMOSS**: [https://www.open-moss.com](https://www.open-moss.com) ## LICENSE Models in MOSS-Audio are licensed under the Apache License 2.0. ## Citation ```bibtex @misc{mossaudio2026, title={MOSS-Audio Technical Report}, author={OpenMOSS Team}, year={2026}, howpublished={\url{https://github.com/OpenMOSS/MOSS-Audio}}, note={GitHub repository} } ```