Assault rifle sound levels as seen from up on decibel scale. To shooting direction (up in drawing) the sonic crack or flight noise of a supersonic bullet produces almost equally high noise levels with and without a suppressor. To the sides and back even supersonic standard ammo can be suppressed to comfortable levels. With subsonic ammo, a suppressor drops the noise level significantly also to the front of the rifle. A right hand shooter's "shade" on noise level curves can clearly be seen at back (in picture down) and left of the rifle position in the center of the diagram. Equally easily one can notice the "bulges" in curves to the back and right resulting from gas bleed of a gas operated Kalashnikov type action.
Directional Diagram