SRD:Greater Shout

You emit an ear-splitting yell that deafens and damages creatures in its path. Any creature within the area is stunned for 1 round and deafened for 4d6 rounds, and takes 10d6 points of sonic damage (or 1d6 points of sonic damage per caster level, maximum 20d6, against exposed brittle or crystalline objects or crystalline creatures). Any exposed brittle or crystalline object or crystalline creature takes 1d6 points of sonic damage per caster level (maximum 15d6). A creature in the area of the cone can negate the stunning and halve both the damage and the duration of the deafness with a successful Fortitude save. A creature holding vulnerable objects can attempt a Reflex save to negate the damage to those objects.

A shout spell cannot penetrate a silence spell.

Arcane Focus: A small metal or ivory horn.