Improvement of the aural nondetectability range and crew compartment noise reduction have become critical factors affecting battlefield survivability of combat vehicles. A Detroit Diesel research program, funded by the United States Navy David Taylor Research Center, has documented the acoustical signature of a Light Armored Vehicle (LAV) under a variety of operating conditions. United States Army Military Standard 1474C criteria were used to define the one third octave aural nondetectability limits of the LAV. Based on a power train noise source analysis, experimental noise control measures were fabricated and tested on the LAV. Preliminary results suggest passive and active noise treatments have substantially reduced the acoustical signature of the LAV.