The Collaborative International Dictionary of English v.0.48:

Reverberative \Re*ver"ber*a*tive\, a.
   Of the nature of reverberation; tending to reverberate;
   reflective.
   [1913 Webster]

         This reverberative influence is that which we have
         intended above, as the influence of the mass upon its
         centers.                                 --I. Taylor.
   [1913 Webster]

WordNet (r) 3.0 (2006):

reverberative
    adj 1: characterized by resonance; "a resonant voice"; "hear the
           rolling thunder" [syn: resonant, resonating,
           resounding, reverberating, reverberative]