Open Whisper-style Speech Model (OWSM) is the first fully open Whisper-style speech foundation model. It reproduces and advances OpenAI's Whisper-style training using publicly available data and open-source toolkits. The code, pre-trained model weights, and training logs are publicly released to promote open science in speech foundation models.

Inference examples can be found on our project page. The Gradio demo is here.

OWSM v4 is the latest version in the OWSM series, which significantly outperforms OWSM v3.1 in LID and multilingual ASR. Additionally, OWSM v4 applies 8 times subsampling (instead of 4 times in OWSM v3.1) to the log Mel features, leading to a final resolution of 80 ms in the encoder. When running inference, we recommend setting maxlenratio=1.0 (default) instead of smaller values.

This repo contains a medium-sized model with 1B parameters, developed by Yifan Peng (CMU). It is trained on 320k hours of public speech data. The newly curated data are publicly released: https://huggingface.co/datasets/espnet/yodas_owsmv4

It supports the following speech-to-text tasks:

Language identification
Speech recognition
Speech translation
Utterance-level timestamp prediction
Long-form recognition or translation

OWSM series

Encoder-decoder OWSM

Name	Size	Hugging Face Repo
OWSM v3.1 base	101M	https://huggingface.co/espnet/owsm_v3.1_ebf_base
OWSM v3.1 small	367M	https://huggingface.co/espnet/owsm_v3.1_ebf_small
OWSM v3.1 medium	1.02B	https://huggingface.co/espnet/owsm_v3.1_ebf
OWSM v3.2 small	367M	https://huggingface.co/espnet/owsm_v3.2
OWSM v4 base	102M	https://huggingface.co/espnet/owsm_v4_base_102M
OWSM v4 small	370M	https://huggingface.co/espnet/owsm_v4_small_370M
OWSM v4 medium	1.02B	https://huggingface.co/espnet/owsm_v4_medium_1B

CTC-based OWSM

Name	Size	Hugging Face Repo
OWSM-CTC v3.1 medium	1.01B	https://huggingface.co/espnet/owsm_ctc_v3.1_1B
OWSM-CTC v3.2 medium	1.01B	https://huggingface.co/espnet/owsm_ctc_v3.2_ft_1B
OWSM-CTC v4 medium	1.01B	https://huggingface.co/espnet/owsm_ctc_v4_1B

Citations

OWSM v4

BibTex

@inproceedings{owsm-v4,
  title={{OWSM} v4: Improving Open Whisper-Style Speech Models via Data Scaling and Cleaning},
  author={Yifan Peng and Shakeel Muhammad and Yui Sudo and William Chen and Jinchuan Tian and Chyi-Jiunn Lin and Shinji Watanabe},
  booktitle={Proceedings of the Annual Conference of the International Speech Communication Association (INTERSPEECH)},
  year={2025},
}

OWSM-CTC

BibTex

@inproceedings{owsm-ctc,
    title = "{OWSM}-{CTC}: An Open Encoder-Only Speech Foundation Model for Speech Recognition, Translation, and Language Identification",
    author = "Peng, Yifan  and
      Sudo, Yui  and
      Shakeel, Muhammad  and
      Watanabe, Shinji",
    booktitle = "Proceedings of the Annual Meeting of the Association for Computational Linguistics (ACL)",
    year = "2024",
    month= {8},
    url = "https://aclanthology.org/2024.acl-long.549",
}

OWSM v3.1 and v3.2

BibTex

@inproceedings{owsm-v32,
  title={On the Effects of Heterogeneous Data Sources on Speech-to-Text Foundation Models},
  author={Jinchuan Tian and Yifan Peng and William Chen and Kwanghee Choi and Karen Livescu and Shinji Watanabe},
  booktitle={Proceedings of the Annual Conference of the International Speech Communication Association (INTERSPEECH)},
  year={2024},
  month={9},
  pdf="https://arxiv.org/pdf/2406.09282"
}
@inproceedings{owsm-v31,
  title={{OWSM v3.1: Better and Faster Open Whisper-Style Speech Models based on E-Branchformer}},
  author={Yifan Peng and Jinchuan Tian and William Chen and Siddhant Arora and Brian Yan and Yui Sudo and Muhammad Shakeel and Kwanghee Choi and Jiatong Shi and Xuankai Chang and Jee-weon Jung and Shinji Watanabe},
  booktitle={Proceedings of the Annual Conference of the International Speech Communication Association (INTERSPEECH)},
  year={2024},
  month={9},
  pdf="https://arxiv.org/pdf/2401.16658",
}

Initial OWSM (v1, v2, v3)

BibTex

@inproceedings{owsm,
  title={Reproducing Whisper-Style Training Using An Open-Source Toolkit And Publicly Available Data},
  author={Yifan Peng and Jinchuan Tian and Brian Yan and Dan Berrebbi and Xuankai Chang and Xinjian Li and Jiatong Shi and Siddhant Arora and William Chen and Roshan Sharma and Wangyou Zhang and Yui Sudo and Muhammad Shakeel and Jee-weon Jung and Soumi Maiti and Shinji Watanabe},
  booktitle={Proceedings of the IEEE Automatic Speech Recognition and Understanding Workshop (ASRU)},
  year={2023},
  month={12},
  pdf="https://arxiv.org/pdf/2309.13876",
}

espnet/owsm_v4_medium_1B

OWSM series

Encoder-decoder OWSM

CTC-based OWSM

Citations

OWSM v4

OWSM-CTC

OWSM v3.1 and v3.2

Initial OWSM (v1, v2, v3)

espnet/
owsm_v4_medium_1B