Source : Webster's Revised Unabridged Dictionary (1913)

Loudness \Loud"ness\, n.
   The quality or state of being loud.

Source : WordNet®

loudness
     n 1: the magnitude of sound (usually in a specified direction);
          "the kids played their music at full volume" [syn: {volume},
           {intensity}] [ant: {softness}]
     2: tasteless showiness [syn: {flashiness}, {garishness}, {gaudiness},
         {brashness}, {meretriciousness}, {tawdriness}, {glitz}]