HiKE: Hierarchical Evaluation Framework for Korean-English Code-Switching Speech Recognition

Gio Paik*, Yongbeom Kim, Soungmin Lee, Sangmin Ahn†, and Chanwoo Kim†, Under Review
* Corresponding Author, † Equal Contribution

✨ Code | 🤗 Dataset | 📖 Paper

Introduction

HiKE is the first Korean-English Code-Switching (CS) Automatic Speech Recognition (ASR) benchmark composed of high-quality, natural CS data across various topics. We use Mixed Error Rate (MER) and Point of Interest Error Rate (PIER) [1] to precisely evaluate the models' CS ASR capability.

Experimental results show that all multilingual ASR models exhibit significantly higher error rates on code-switching data, and that their CS-ASR capabilities can be improved through fine-tuning.

For further details, please refer to our paper.

[1] Ugan et al., “PIER: A Novel Metric for Evaluating What Matters in Code-Switching”, ICASSP 2025

Hierarchical CS-Level Labels

To provide more fine-grained comparison of model performance on different forms of code-switching, we labeled each utterance according to the following levels:

• Word-level CS: Code-switching that occurs at the word level, typically as the substitution of a single noun or adjective.
• Phrase-level CS: Occurs when a multi-word phrase within a sentence appears in another language.
• Sentence-level CS: The alternation between languages on a sentence-by-sentence basis.

Loanword Labels

Loanwords are words adopted from a foreign language and adapted to the phonology and orthography of the new language. For example, the Korean loanword '버스' [bəs] and the English word 'bus' [bʌs] are pronounced almost identically and can be used interchangeably in a CS context. To avoid this problem, we meticulously labeled all loanwords contained in our dataset.

Sample Usage

Install Dependencies

git clone --recurse-submodules https://github.com/ThetaOne-AI/HiKE
cd HiKE
pip install -r requirements.txt
apt-get update && apt-get install -y ffmpeg  # install ffmpeg if needed

Run Evaluation

bash scripts/evaluate_whisper.sh
# or
python src/main.py --model whisper --model_name openai/whisper-large --batch_size 8

The results will be saved in ./outputs.

Evaluate Your Model

• Implement a class that follows the BaseASR interface in src/models/your_model.py, and register it in src/main.py.

Create src/models/your_model.py:

from typing import List, Dict, Any
from src.models import BaseASR


class YourModel(BaseASR):
    def __init__(self, model_name: str = "your/model-or-config"):
        self.model_name = model_name
        # TODO: load your model or client here

    def generate(self, input, batch_size: int | None = None, **kwargs) -> List[Dict[str, Any]]:
        if not isinstance(input, list):
            input = [input]
        return [{"text": your_transcribe_fn(x)} for x in input]

Register in src/main.py:

elif model == "your_model":
    from models.your_model import YourModel
    asr = YourModel(model_name)

Run:

python src/main.py --model your_model --model_name your/model-or-name

Citation

@misc{paik2025hike,
      title={{HiKE}: Hierarchical Evaluation Framework for Korean-English Code-Switching Speech Recognition}, 
      author={Gio Paik and Yongbeom Kim and Soungmin Lee and Sangmin Ahn and Chanwoo Kim},
      year={2025},
      eprint={2509.24613},
      archivePrefix={arXiv},
      primaryClass={cs.CL},
      url={https://arxiv.org/abs/2509.24613}, 
}