wall of silence

A 10 foot wide and 30 foot high and 1 foot thick wall appears in a place you can see. The wall is transparent and viscous preventing any sound from passing through it. A creature who ends its' turn inside the wall must make a constitution save equal to your spell save DC, on a failed save the creature is deafened. Casting at a higher level allows you to place one extra wall in another area you can see.