You need to carefully check the audio just like for every other dataset. The rules for a good datasets apply here as well.
Looking at the german M-AILABS datasets I found in some cases the text transcript does not match perfectly the spoken text, I also found that audio files are not properly edited and the last syllables of a sentence is missing sometimes.
Depending on the speaker and the story the reading speech and tonality might be varying when the speaker mimics different voices or emotions.
Donât know if this is a real problem, but the Librivox books are mostly older books (where copyright has expired ) so the vocabulary is somewhat outdated and model might have problems pronouncing âmodern wordsâ like âcomputerâ or âcoronavirusâ