Ashwin Sankar


2025

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Towards Building Large Scale Datasets and State-of-the-Art Automatic Speech Translation Systems for 14 Indian Languages
Ashwin Sankar | Sparsh Jain | Nikhil Narasimhan | Devilal Choudhary | Dhairya Suman | Mohammed Safi Ur Rahman Khan | Anoop Kunchukuttan | Mitesh M Khapra | Raj Dabre
Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

Speech translation for Indian languages remains a challenging task due to the scarcity of large-scale, publicly available datasets that capture the linguistic diversity and domain coverage essential for real-world applications. Existing datasets cover a fraction of Indian languages and lack the breadth needed to train robust models that generalize beyond curated benchmarks. To bridge this gap, we introduce BhasaAnuvaad, the largest speech translation dataset for Indian languages, spanning over 44 thousand hours of audio and 17 million aligned text segments across 14 Indian languages and English. Our dataset is built through a threefold methodology: (a) aggregating high-quality existing sources, (b) large-scale web crawling to ensure linguistic and domain diversity, and (c) creating synthetic data to model real-world speech disfluencies. Leveraging BhasaAnuvaad, we train IndicSeamless, a state-of-the-art speech translation model for Indian languages that performs better than existing models. Our experiments demonstrate improvements in the translation quality, setting a new standard for Indian language speech translation. We will release all the code, data and model weights in the open-source, with permissive licenses to promote accessibility and collaboration.

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Mark My Words: A Robust Multilingual Model for Punctuation in Text and Speech Transcripts
Sidharth Pulipaka | Ashwin Sankar | Raj Dabre
Proceedings of the 14th International Joint Conference on Natural Language Processing and the 4th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics

Punctuation plays a vital role in structuring meaning, yet current models often struggle to restore it accurately in transcripts of spontaneous speech, especially in the presence of disfluencies such as false starts and backtracking. These limitations hinder the performance of downstream tasks like translation, text-to-speech, summarization, etc. where sentence boundaries are critical for preserving quality. In this work, we introduce Cadence, a generalist punctuation restoration model adapted from a pretrained large language model. Cadence is designed to handle both clean written text and highly spontaneous spoken transcripts. It surpasses the previous state-of-the-art in performance while expanding support from 14 to all 22 Indian languages and English. We conduct a comprehensive analysis of model behavior across punctuation types and language families, identifying persistent challenges under domain shift and with rare punctuation marks. Our findings demonstrate the efficacy of utilizing pretrained language models for multilingual punctuation restoration and highlight Cadence’s practical value for low-resource NLP pipelines at scale.

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Findings of the IWSLT 2025 Evaluation Campaign
Idris Abdulmumin | Victor Agostinelli | Tanel Alumäe | Antonios Anastasopoulos | Luisa Bentivogli | Ondřej Bojar | Claudia Borg | Fethi Bougares | Roldano Cattoni | Mauro Cettolo | Lizhong Chen | William Chen | Raj Dabre | Yannick Estève | Marcello Federico | Mark Fishel | Marco Gaido | Dávid Javorský | Marek Kasztelnik | Fortuné Kponou | Mateusz Krubiński | Tsz Kin Lam | Danni Liu | Evgeny Matusov | Chandresh Kumar Maurya | John P. McCrae | Salima Mdhaffar | Yasmin Moslem | Kenton Murray | Satoshi Nakamura | Matteo Negri | Jan Niehues | Atul Kr. Ojha | John E. Ortega | Sara Papi | Pavel Pecina | Peter Polák | Piotr Połeć | Ashwin Sankar | Beatrice Savoldi | Nivedita Sethiya | Claytone Sikasote | Matthias Sperber | Sebastian Stüker | Katsuhito Sudoh | Brian Thompson | Marco Turchi | Alex Waibel | Patrick Wilken | Rodolfo Zevallos | Vilém Zouhar | Maike Züfle
Proceedings of the 22nd International Conference on Spoken Language Translation (IWSLT 2025)

This paper presents the outcomes of the shared tasks conducted at the 22nd International Workshop on Spoken Language Translation (IWSLT). The workshop addressed seven critical challenges in spoken language translation: simultaneous and offline translation, automatic subtitling and dubbing, model compression, speech-to-speech translation, dialect and low-resource speech translation, and Indic languages. The shared tasks garnered significant participation, with 32 teams submitting their runs. The field’s growing importance is reflected in the increasing diversity of shared task organizers and contributors to this overview paper, representing a balanced mix of industrial and academic institutions. This broad participation demonstrates the rising prominence of spoken language translation in both research and practical applications.