Plumbers usually put in a few "air chambers" which are vertical, capped pipes on the water lines above faucets. they're usually around a foot tall. When the pipes are filled with water, these dead-end pipes have a pocket of air in them that acts like a shock absorber for the water pressure changes.
Since you don't want to break up the wall, you might try turning off the water to the house, draining the lines, and then refilling them hopefully to refresh any air pockets that might have dissapated over time.