laughter vs sob

laughter

noun
  • The sound of laughing, produced by air so expelled; any similar sound. 

  • A movement (usually involuntary) of the muscles of the laughing face, particularly of the lips, and of the whole body, with a peculiar expression of the eyes, indicating merriment, satisfaction or derision, and usually attended by a sonorous and interrupted expulsion of air from the lungs. 

sob

noun
  • sound of sob 

  • A cry with a short, sudden expulsion of breath. 

verb
  • To soak. 

  • To say (something) while sobbing. 

  • To weep with convulsive gasps. 

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