Introduction

Llama-Mimi is a speech language model that uses a unified tokenizer (Mimi) and a single Transformer decoder (Llama) to jointly model sequences of interleaved semantic and acoustic tokens. Trained on ~240k hours of English audio, Llama-Mimi achieves state-of-the-art performance in acoustic consistency on SALMon and effectively preserves speaker identity.

Visit our demo site to hear generated speech samples.

Repository Overview

This repository lets you:

• Run inference with our pretrained models
• Pre-train Llama-Mimi on The People's Speech
• Evaluate the model on multiple benchmarks

Setup

Install dependencies using uv:

uv sync

Generate Speech

Generate audio continuations from a given audio prompt using our pretrained model (Llama-Mimi-1.3B):

uv run python inference.py

▶️ Listen to samples on our demo site

Pre-train Llama-Mimi on The People's Speech

To pre-train Llama-Mimi on The People's Speech (30k hours), first download the dataset locally:

uv run huggingface-cli download  MLCommons/peoples_speech  --repo-type dataset --local-dir data/peoples_speech

Then launch training with:

torchrun --nproc_per_node=8 --local-ranks-filter 0 \
      --role rank --tee 3 -m torchtitan.train \
      --job.config_file config/llama3_2_1b_peoples_speech.toml

This configuration trains Llama-Mimi-1.3B for 5,000 steps with a global batch size of 1,024 on 8 GPUs, taking about 8 hours. Training progress can be monitored with Weights & Biases (W&B).

To use a custom dataset, update the configuration in torchtitan/datasets/hf_dataset.py. We recommend downloading multiple large datasets, shuffling them, and then using load_dataset() with local files.

After training, convert dcp checkpoint to HuggingFace format to use the model with transformers library:

uv run python scripts/convert_dcp_to_hf.py

Evaluation

Evaluate models on SALMon, sLM21 (sWUGGY and sBLIMP), and sStoryCloze tasks.

SALMon:

uv run python eval/salmon.py --model_name llm-jp/Llama-Mimi-1.3B

sStoryCloze:

uv run python eval/sStoryCloze.py --model_name llm-jp/Llama-Mimi-1.3B

sLM21:

uv run python eval/sLM21.py --model_name llm-jp/Llama-Mimi-1.3B

Acknowledge

• Our training code is built on top of TorchTitan.

• Our model employs Llama 3 as the base language model, and Mimi as the audio tokenizer.

Citation

Star us on GitHub if you find this repository useful! ⭐

If you find this work interesting, please cite our paper:

@misc{sugiura2025llamamimispeechlanguagemodels,
      title={Llama-Mimi: Speech Language Models with Interleaved Semantic and Acoustic Tokens},
      author={Issa Sugiura and Shuhei Kurita and Yusuke Oda and Ryuichiro Higashinaka},
      year={2025},
      eprint={2509.14882},
      archivePrefix={arXiv},
      primaryClass={cs.CL},
      url={https://arxiv.org/abs/2509.14882},
}