Toward domain-invariant speech recognition via large scale training
Table 4: Results using models trained with and without codec simulation. All of the results are on the Voicesearch test set.
['[BOLD] Test set', '[BOLD] Word error rate  [BOLD] w/o codec', '[BOLD] Word error rate  [BOLD] w/ codec']
4.3.2 Codecs Tab. We evaluate on the Voicesearch set under various codec conditions. For the baseline model, performance worsens as the bitrate decreases since lower bitrates imply more lossy encoding. Training with codecs makes the performance under seen and unseen codecs close to not using any codec, even at low bitrates: For MP3 23k, training with codecs improves WER by almost 20%.