Transmutation [Sonic]
Level: Bard 5
Components: V, S
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature
Duration: 24 hours
Saving Throw: Will negates
Spell Resistance: Yes
Your target's voice rends the air around her, shredding her from within.
Each time the subject casts a spell with a verbal component, she deals 2d6 points of sonic damage to all creatures within 10 feet of her (including herself). She must then succeed on a Concentration check (DC 15 + damage dealt + spell level) to avoid losing the spell.
Source: Complete Mage, page 102.