examine vs sound out

examine

verb
  • to observe or inspect carefully or critically 

  • to interrogate 

  • to determine the aptitude, skills or qualifications of someone by subjecting them to an examination 

  • to check the health or condition of something or someone 

sound out

verb
  • To question and listen attentively in order to discover a person's opinion, intent, or preference, especially by using indirect conversational remarks. 

  • To pronounce a word or phrase by articulating each of its letters or syllables slowly in sequence. 

  • To speak or sing loudly, to call out. 

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