[Ambush]

Your stealthy attack leaves your foe's head ringing.

Prerequisite: none

Benefit: Your successful sneak attack causes the target to be deafened for 3 rounds. If you use this feat a second time on a target before 3 rounds have elapsed, the effect of the first use expires. Using this feat reduces your sneak attack damage by 3d6.

Rulebook: Complete Scoundrel (p. 76)

Edition: Supplementals (3.5)