muffled vs wordless

muffled

adj
  • Stifled or covered up; diminished by interference. 

wordless

adj
  • Unable or unwilling to speak; dumb, silent or inarticulate. 

  • Conveyed without the use of words; unspoken or unsaid. 

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