Amplitude coda of classical waves in disordered media
  The propagation of classical waves in the presence of a disordered medium is studied. We consider wave pulses containing a broad range of frequencies in terms of the configurationally averaged Green function of the system. Damped oscillations in the time-dependent response trailing behind the direct arrival of the pulse (coda) are predicted, the periods of which are governed by the density of scatterers. 
Mauro S. Ferreira and Gerrit E. W. Bauer