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Step-Audio: The First Production-Ready Open-Source Framework for Intelligent Speech Interaction

Today, a new game changer ai development is created by Chinese Ai Geeks. This is Step-Audio, moving ai talking to the next and more realistic level which is never before.

Let's dive in...

Step-Audio is an open-source framework designed to unify speech comprehension and generation. It supports multilingual conversations, emotional tones, regional dialects, adjustable speech rates, and various prosodic styles, making it an advanced tool for speech-based AI applications.

Developed as an intelligent speech interaction system, Step-Audio boasts a 130B-parameter multimodal model that integrates speech recognition, semantic understanding, dialogue, voice cloning, and speech synthesis. The model is accessible via Hugging Face and Modelscope repositories, making it easy for developers and researchers to use.


Key Features and Innovations

1. 130B-Parameter Multimodal Model

Step-Audio combines comprehension and generation capabilities in a single, unified model. It supports:

  • Speech Recognition
  • Semantic Understanding
  • Dialogue Handling
  • Voice Cloning
  • Speech Synthesis

2. Generative Data Engine

Step-Audio eliminates the manual data collection required in traditional text-to-speech (TTS) systems. Instead, it uses AI-driven generative data to enhance training quality, leading to the release of the efficient Step-Audio-TTS-3B model.

3. Granular Voice Control

Users can fine-tune generated speech with instruction-based controls, adjusting:

  • Emotional tones (e.g., anger, joy, sadness)
  • Dialects (e.g., Cantonese, Sichuanese)
  • Vocal styles (e.g., rap, a cappella humming)

4. Enhanced Intelligence

Step-Audio uses ToolCall mechanisms and role-playing capabilities to improve performance in complex conversational scenarios.


Model Overview

Tokenization Strategy

Step-Audio employs a dual-codebook framework with semantic and acoustic tokenizers:

  • Semantic tokens: 16.7Hz, 1024-entry codebook
  • Acoustic tokens: 25Hz, 4096-entry codebook
  • Temporal alignment: 2:3 ratio (2 semantic tokens per 3 acoustic tokens)

Language Model

  • Based on Step-1, a 130-billion parameter LLM, further enhanced with audio-contextualized pretraining and task-specific post-training.

Speech Decoder

The decoder converts discrete speech tokens into continuous waveforms using:

  • Flow Matching
  • Neural Vocoding

The dual-code interleaving approach ensures smooth integration of semantic and acoustic features.

Real-time Inference Pipeline

Step-Audio optimizes real-time interactions using:

  • Voice Activity Detection (VAD)
  • Streaming Audio Tokenizer
  • Step-Audio Language Model & Speech Decoder
  • Context Manager for preserving conversational continuity

The pipeline reduces latency and ensures efficient processing.


Installation and Setup

1. System Requirements

  • GPU: Minimum 1.5GB VRAM, recommended 4x A800/H800 GPUs (80GB)
  • Operating System: Linux
  • Python: 3.10+
  • PyTorch: 2.3+ with CUDA

2. Installation Steps

# Clone the repository
git clone https://github.com/stepfun-ai/Step-Audio.git
cd Step-Audio

# Create a virtual environment
conda create -n stepaudio python=3.10
conda activate stepaudio

# Install dependencies
pip install -r requirements.txt

# Clone necessary model files
git lfs install
git clone https://huggingface.co/stepfun-ai/Step-Audio-Tokenizer
git clone https://huggingface.co/stepfun-ai/Step-Audio-Chat
git clone https://huggingface.co/stepfun-ai/Step-Audio-TTS-3B
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Once downloaded, the directory structure should be:

where_you_download_dir
├── Step-Audio-Tokenizer
├── Step-Audio-Chat
├── Step-Audio-TTS-3B
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Model Usage and Inference

Offline Inference

To generate text/audio outputs from audio/text inputs:

python offline_inference.py --model-path where_you_download_dir
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TTS Inference (Text-to-Speech)

python tts_inference.py --model-path where_you_download_dir --output-path where_you_save_audio_dir --synthesis-type use_tts_or_clone
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For voice cloning, a speaker information dictionary is required:

{
    "speaker": "speaker id",
    "prompt_text": "content of prompt wav",
    "wav_path": "prompt wav path"
}
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Launching a Web Demo

For an interactive experience, start a local web server:

python app.py --model-path where_you_download_dir
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Benchmark Performance

Step-Audio demonstrates competitive performance across automatic speech recognition (ASR), text-to-speech (TTS), and conversational AI benchmarks.

ASR (Automatic Speech Recognition) Performance

Compared with Whisper Large-v3, Qwen2-Audio, MinMo, LUCY, Moshi, and GLM-4-Voice, Step-Audio achieves superior ASR results in:

  • Aishell-1
  • Aishell-2
  • Wenetspeech
  • Librispeech

TTS Performance

Step-Audio-TTS-3B demonstrates best-in-class CER/WER scores, outperforming:

  • FireRedTTS
  • MaskGCT
  • CosyVoice
  • CosyVoice 2

Voice Chat Capabilities

On StepEval-Audio-360, a multi-turn benchmark, Step-Audio outperforms:

  • GLM-4-Voice
  • Qwen2-Audio
  • Moshi
  • LUCY

Scoring higher in factuality, relevance, and chat experience, it also excels in role-playing, creativity, and emotional control.


Example Use Cases

1. Voice Cloning

Step-Audio replicates speaker-specific voice features, as seen in the following examples:
| Speaker | Prompt Audio | Cloned Audio |
|---------|-------------|-------------|
| 于谦 | Google Drive | Google Drive |
| 李雪琴 | Google Drive | Google Drive |

2. Speech Speed Control

Adjustable speech rate example:
| Prompt | Response |
|--------|---------|
| Fast Mode: "Say a tongue twister." | Listen |
| Slow Mode: "Say it again very, very slowly." | Listen |

3. Emotional and Tone Control

Step-Audio modifies emotional tone dynamically, e.g.:
| Prompt | Response |
|--------|---------|
| "You sound robotic. Try being more expressive!" | Listen |

4. Multilingual Capabilities

Step-Audio supports Chinese, English, and Japanese, e.g.:
| Prompt | Response |
|--------|---------|
| "What does 'raining cats and dogs' mean?" | Listen |

5. Rap and Singing

Step-Audio can generate music, e.g.:
| Prompt | Response |
|--------|---------|
| "Sing a rap song!" | Listen |


Final Words...

Step-Audio is a powerful and versatile speech AI framework that sets a new standard for open-source speech comprehension, generation, and interaction. With robust ASR, TTS, and voice chat capabilities, it is an ideal choice for developers and researchers looking to integrate cutting-edge speech AI into their applications.

For further details, visit the GitHub Repository or Hugging Face Model Page.

Top comments (1)

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haseeb_ahmad_cd7607980765 profile image
Haseeb Ahmad

This is a game-changer for AI-driven speech interaction! 🚀 Step-Audio’s ability to unify speech comprehension and generation, along with granular voice control, makes it a revolutionary open-source framework. The multilingual support and emotional tone adjustments are especially impressive!

For more insights on AI developments and tech trends, check out these resources:
🔹 DeltaMaath
🔹 GoodNotes Guide
🔹 Showmax Links

Excited to see how this framework evolves! 🔥