A translucent barrier of pure sound springs into existence. This wall is silent except for a faint hum, but bursts with discordant noise when touched by an object or creature. The wall deflects arrows, bolts, loose debris, and Small or smaller flying creatures like a wind wall spell, except these things rebound harmlessly rather than being directed upward. The burst of discordant noise deals 2d4 points of sonic damage to creatures within 10 feet of the triggering object or creature; touching or passing through the wall deals 2d6 points of sonic damage + 1 point of sonic damage per caster level (maximum +20). If you evoke the wall so that it appears where creatures are, each creature takes damage as if passing through the wall. A silence spell suppresses the wall within its area, but the wall reappears when the silence ends.