The Collaborative International Dictionary of English v.0.48:

Crepitation \Crep`i*ta"tion\ (kr?p`?-t?"sh?n), n. [Cf. F.
   cr['e]pitation.]
   1. The act of crepitating or crackling.
      [1913 Webster]

   2. (Med.)
      (a) A grating or crackling sensation or sound, as that
          produced by rubbing two fragments of a broken bone
          together, or by pressing upon cellular tissue
          containing air.
      (b) A crepitant r[^a]le.
          [1913 Webster]

WordNet (r) 3.0 (2006):

crepitation
    n 1: the sharp sound of snapping noises [syn: crackle,
         crackling, crepitation]