The Collaborative International Dictionary of English v.0.48:

crepitant \crep"i*tant\ (kr?p"?-tant), a. [See Crepitate.]
   Having a crackling sound; crackling; rattling.
   [1913 Webster]

   Crepitant rale (Med.), a peculiar crackling sound audible
      with inspiration in pneumonia and other lung disease.
      [1913 Webster]