blurt vs mussitate

blurt

verb
  • To utter suddenly and unadvisedly; to speak quickly or without thought; to divulge inconsiderately — commonly with out. 

noun
  • An abrupt outburst. 

mussitate

verb
  • To say (words, etc.) indistinctly; to mutter. 

  • To talk indistinctly; to mutter. 

How often have the words blurt and mussitate occurred in a corpus of books? (source: Google Ngram Viewer )