Granary: Speech Recognition and Translation Dataset in 25 European Languages
Nithin Rao Koluguri, Monica Sekoyan, George Zelenfroynd, Sasha Meister, Shuoyang Ding, Sofia Kostandian, He Huang, Nikolay Karpov, Jagadeesh Balam, Vitaly Lavrukhin, Yifan Peng, Sara Papi, Marco Gaido, Alessio Brutti, Boris Ginsburg
TL;DR
Granary tackles the data scarcity problem in multilingual speech by introducing an open-source, end-to-end pseudo-labeling pipeline for ASR and AST across 25 European languages. The approach combines long-form audio segmentation, two-pass inference, LID verification, robust filtration, and LLM-based punctuation restoration to generate high-quality pseudo-labeled data at scale, then uses EuroLLM for translation pseudo-labeling with a NeMo-Curator filtration step. The study processes roughly 1 million hours of unlabeled data to produce about 638k hours for ASR and 351k hours for AST, achieving strong retention (≈60%) and enabling performance on par with larger, manually labeled datasets using roughly half the data. Evaluation on English and Croatian shows Granary-filtered data yields comparable or improved WER relative to MOSEL, with notable gains on FLEURS and low-resource settings, highlighting the practical impact for building open, multilingual speech models. Future work aims to release multi-task, multilingual models trained on the full Granary corpus, further broadening accessibility and impact.
Abstract
Multi-task and multilingual approaches benefit large models, yet speech processing for low-resource languages remains underexplored due to data scarcity. To address this, we present Granary, a large-scale collection of speech datasets for recognition and translation across 25 European languages. This is the first open-source effort at this scale for both transcription and translation. We enhance data quality using a pseudo-labeling pipeline with segmentation, two-pass inference, hallucination filtering, and punctuation restoration. We further generate translation pairs from pseudo-labeled transcriptions using EuroLLM, followed by a data filtration pipeline. Designed for efficiency, our pipeline processes vast amount of data within hours. We assess models trained on processed data by comparing their performance on previously curated datasets for both high- and low-resource languages. Our findings show that these models achieve similar performance using approx. 50% less data. Dataset will be made available at https://hf.co/datasets/nvidia/Granary
