euphonious vs unlistenable

euphonious

adj
  • Of sounds, especially speech: demonstrating or possessing euphony; agreeable to the ear; pleasant-sounding. 

unlistenable

adj
  • Of a sound quality or characteristic that a person cannot long listen to. 

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