In real-world settings, the availability of target-domain data needed for fine-tuning Automatic Speech Recognition systems can be limited. In such low-resource settings, one way of improving the performance of models is training on out-of-domain data that bears similarity to the target domain. Once such data is selected, it is traditionally provided to the model in an ad-hoc, random manner during training, which can lead to sub-optimal results. We propose Domain-Aware Scheduling (DAS): grouping out-of-domain examples by distance to the target domain and training sequentially from farthest to closest, always continuing from the best checkpoint. This schedule outperforms strong data selection baselines by 11.3% (2.5 WER points) on average, using only one minute of in-domain seed data. This makes DAS attractive for practitioners who cannot rely on large in-domain corpora, e.g., in low-resource or privacy constrained settings.

