SwitchLingua: The First Large-Scale Multilingual and Multi-Ethnic Code-Switching Dataset

TL;DR

This paper introduces SwitchLingua, a large-scale, diverse multilingual and multi-ethnic code-switching dataset, along with a new semantic-aware evaluation metric for improved ASR system assessment.

Contribution

It presents the first extensive multilingual, multi-ethnic code-switching dataset and a semantic-aware error rate metric to better evaluate multilingual ASR performance.

Findings

420K textual code-switching samples across 12 languages

Over 80 hours of audio from 174 speakers of diverse backgrounds

Introduction of the Semantic-Aware Error Rate (SAER) metric

Abstract

Code-switching (CS) is the alternating use of two or more languages within a conversation or utterance, often influenced by social context and speaker identity. This linguistic phenomenon poses challenges for Automatic Speech Recognition (ASR) systems, which are typically designed for a single language and struggle to handle multilingual inputs. The growing global demand for multilingual applications, including Code-Switching ASR (CSASR), Text-to-Speech (CSTTS), and Cross-Lingual Information Retrieval (CLIR), highlights the inadequacy of existing monolingual datasets. Although some code-switching datasets exist, most are limited to bilingual mixing within homogeneous ethnic groups, leaving a critical need for a large-scale, diverse benchmark akin to ImageNet in computer vision. To bridge this gap, we introduce \textbf{LinguaMaster}, a multi-agent collaboration framework specifically designed for efficient and scalable multilingual data synthesis. Leveraging this framework, we curate \textbf{SwitchLingua}, the first large-scale multilingual and multi-ethnic code-switching dataset, including: (1) 420K CS textual samples across 12 languages, and (2) over 80 hours of audio recordings from 174 speakers representing 18 countries/regions and 63 racial/ethnic backgrounds, based on the textual data. This dataset captures rich linguistic and cultural diversity, offering a foundational resource for advancing multilingual and multicultural research. Furthermore, to address the issue that existing ASR evaluation metrics lack sensitivity to code-switching scenarios, we propose the \textbf{Semantic-Aware Error Rate (SAER)}, a novel evaluation metric that incorporates semantic information, providing a more accurate and context-aware assessment of system performance.