crackle vs susurrus

crackle

noun
  • A prolonged, frequent cracking sound; a fizzing, popping sound. 

  • Synonym of crackling (“crispy rind of roast pork”) 

  • A style of glaze giving the impression of many small cracks. 

  • The fifth derivative of the position vector with respect to time (after velocity, acceleration, jerk, and jounce), i.e. the rate of change of jounce. 

verb
  • To make a prolonged, frequent cracking sound which sounds like fizzing or popping. 

susurrus

noun
  • A whispering or rustling sound; a murmur. 

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