The best way to supress the vibrations is to hang it from some nylon cord or string that is strong enough. It may vibrate the tent frame so see if there is a way to hang something from the ceiling instead from butterfly hook or plant hanger, the long string usually absorbs the vibrations and you can still hear it when close but normally not when your a bit away from it as most of the sound is the vibration not the actual motor. Try rigging something along this thinking, normally covering with shit or burying in padding will smother the air pump and it DOES need to breathe, if you completely smother the motor will burn up and it may be hazard