Bengali-English and Hindi-English Code Mixed Speech Data with Disfluencies
Paper · 2026 · Anuran Mitra, Tapabrata Mondal, Anirvan Chakravarty et al.
Summary
Most Bengali–English and Hindi–English speech corpora contain clean, scripted speech. Real Indian conversation mixes languages and includes hesitations, so ASR systems built on fluent data handle it poorly. Recording such natural speech is expensive, particularly when only about an hour of data is realistic. The authors created BEHE-CMDisfl, a synthetic corpus built in two stages. First, ChatGPT (GPT-5) was prompted, zero-shot and few-shot, to write informal multi-speaker dialogues covering everyday, service, classroom, healthcare and social-media topics. Bengali or Hindi served as the matrix language and English as the embedded one, and the prompts asked for injected filled pauses, repetitions and restarts. Second, Indic Parler TTS converted the dialogues to audio. To check whether the data is usable, they trained Kaldi GMM-HMM models on a 1.3-hour Bengali–English subset. The best word error rate was 37.74%, and most of the gains came from consistent lexicon entries and normalized transliteration rather than from more complex models. The recognized output kept the disfluency tokens instead of discarding them. The resource offers a controlled testbed for disfluency-aware code-mixed ASR, but results still need checking on real speech.
Key points
- Pipeline: LLM-generated code-mixed disfluent dialogues (ChatGPT, GPT-5) were voiced with AI4Bharat's Indic Parler TTS. The corpus covers Bengali–English (BE) and Hindi–English (HE). It extends the text-only MixFluent work into audio.
- Baselines: Kaldi Monophone, Triphone and LDA-MLLT models were trained on a 1.3 h BE subset. The Triphone model reached 39.23% WER. Widening the decoding beam gave the best result, 37.74% WER. HE ASR experiments are still planned.
- Normalization matters: Unifying inconsistent romanizations (e.g., "ar" vs "aar") and keeping the lexicon consistent mattered more than model complexity.
- Disfluencies are recognized: When they had lexicon entries, hesitation sounds like "um", self-corrections like "i mean" and doubled words like "oh oh" showed up correctly in the decoded transcripts.
- Limitations: The audio is synthetic, and no significance testing was done. The authors cite a 47.10% Wav2Vec2 WER from a different study using 10 h of data, but this is not a controlled comparison. Future plans include a 3–5 h real-speech gold set to measure the sim-to-real gap and extension to Tamil, Marathi and Telugu.
Institutions
Fields, topics and concepts
📚 Shelves 5The field of science this work belongs to (OpenAlex fields).Computer Science · 18,614 worksArtificial Intelligence · 17,965 worksArts and Humanities · 17,450 worksLanguage and Linguistics · 17,296 worksSignal Processing · 493 works
🧭 Topics 3Research subjects and languages the work is about.English · 2,379 worksMultilingual & cross-lingual NLP · 882 worksSpeech & spoken language · 519 works
Cite
Cite as Anuran Mitra, Tapabrata Mondal, Anirvan Chakravarty and Sivaji Bandyopadhyay. 2026. Bengali-English and Hindi-English Code Mixed Speech Data with Disfluencies. Proceedings of the 8th Workshop on Indian Language Data: Resources and Evaluation.
@inproceedings{mitra2026bengali,
title = {{Bengali-English and Hindi-English Code Mixed Speech Data with Disfluencies}},
author = {Anuran Mitra, Tapabrata Mondal, Anirvan Chakravarty and Sivaji Bandyopadhyay},
booktitle = {Proceedings of the 8th Workshop on Indian Language Data: Resources and Evaluation},
year = {2026},
doi = {10.63317/254iufgehzzc},
url = {https://doi.org/10.63317/254iufgehzzc}
}References
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