To Distill or Not to Distill? On the Robustness of Robust Knowledge Distillation
Abdul Waheed, Karima Kadaoui, Muhammad Abdul-Mageed
TL;DR
This work evaluates the robustness of multilingual Arabic ASR across dialects and demonstrates that knowledge distillation from a large teacher (Whisper) to compact student models yields substantial efficiency gains without sacrificing accuracy. By introducing a never-seen, human-annotated in-house dialect dataset and evaluating on standard benchmarks, the authors show that distilled models, particularly DW-32-16++, achieve superior or competitive WERs compared to much larger models. An extensive error analysis uncovers dialect-specific failure modes and guides improvements, highlighting the resilience of distilled models to linguistic diversity. The study underscores the practical potential of compute-efficient, dialect-aware ASR systems for low-resource and diverse Arabic-speaking populations, while acknowledging limitations in data realism, compute cost, and bias risk.
Abstract
Arabic is known to present unique challenges for Automatic Speech Recognition (ASR). On one hand, its rich linguistic diversity and wide range of dialects complicate the development of robust, inclusive models. On the other, current multilingual ASR models are compute-intensive and lack proper comprehensive evaluations. In light of these challenges, we distill knowledge from large teacher models into smaller student variants that are more efficient. We also introduce a novel human-annotated dataset covering five under-represented Arabic dialects for evaluation. We further evaluate both our models and existing SoTA multilingual models on both standard available benchmarks and our new dialectal data. Our best-distilled model's overall performance ($45.0$\% WER) surpasses that of a SoTA model twice its size (SeamlessM4T-large-v2, WER=$47.0$\%) and its teacher model (Whisper-large-v2, WER=$55.1$\%), and its average performance on our new dialectal data ($56.9$\% WER) outperforms all other models. To gain more insight into the poor performance of these models on dialectal data, we conduct an error analysis and report the main types of errors the different models tend to make. The GitHub repository for the project is available at \url{https://github.com/UBC-NLP/distill-whisper-ar}.
