Attentional Speech Recognition Models Misbehave on Out-of-domain Utterances
Table 2: Number of echographic examples remaining (out of 170) as a function of the length normalization hyperparameter α. The other decoding hyperparameters are held fixed at the setting in Section 2.2. The in-domain evaluation set is LibriSpeech dev-clean, and the out-of-domain evaluation set is our clean BNC subset.
['[ITALIC] α', '[BOLD] Echographic Utts.', '[BOLD] Libri.\xa0WER', '[BOLD] BNC WER']
However, the performance on the evaluation sets also drops significantly. Even at α=0.0, 11 out of 170 echographic examples continue to yield 200 or more characters of output.