Your rage attacks can cause thunderous roars that can deafen opponents.
Prerequisites: Str 25, rage 5/day.
Benefit: Any weapon the character wields while in a rage is treated as a thundering weapon. The DC of the Fortitude save to resist deafness is equal to 10 + ½ the character’s level. This ability does not stack with similar abilities.
Source: Standard Reference Document under Open Game License v1.0a, which updated this feat originally published in the Epic Level Handbook, page 68.