How to lower sound pressure (i.e. the volume of a sound)?
Not sure what you mean besides the obvious: turn down the volume control, walk away from the speakers, build a wall in front of the speakers, put a muzzle on the dog, put in a DVD of Finding Nemo, tie the marching trumpet player's shoelaces together...
The only way to lower a pressure fluctuation is to decrease the driving fluctuation amplitude. Unless you are really asking about insulation or sound attenuation techniques, then there are things you can do obviously.
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