Europarl-ST: A Multilingual corpus for Speech Translation of Parliamentary Debates
Table 7: BLEU scores of cascade-based SLT experiments with fine-tuned models assessed on the test sets.
['[EMPTY]', 'De', 'En', 'Es', 'Fr']
This section presents the results of the SLT experiments following the cascade approach, in which we use the output of the ASR system as input for the MT system. The output of the ASR system is segmented based on detected silences. We use the fine-tuned MT systems as they outperform the out-of-domain systems in all cases. This is to be expected, as the MT system has to cope not only with error propagation from incorrect transcriptions, but also with a sub-optimal segmentation of the input which might not correspond with whole sentences. As expected, although the overall BLEU scores are lower, the ranking of the performance across translation directions is preserved, with MT systems that obtained the highest scores in the MT experiments, also obtaining the highest scores in the SLT experiments, and vice versa. Although SLT results are constrained by the complexity of this task, these results serve as a good starting baseline for future developments.