Discordant Voice Feat 18
Source Pathfinder Advanced Player's Guide
Prerequisites inspire courage
Your Inspire Courage lets loose a discordant shriek that imbues your allies' attacks with powerful sonic reverberations.
While your allies are affected by your Inspire Courage, their weapon strikes and unarmed attacks deal an additional 1d6 sonic damage.
Effect: Discordant Voice
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
BardThis indicates abilities from the bard class.
EvocationEffects and magic items with this trait are associated with the evocation school of magic, typically involving energy and elemental forces.
SonicAn effect with the sonic trait functions only if it makes sound, meaning it has no effect in an area of silence or in a vacuum. This is different from an auditory spell, which is effective only if the target can hear it. A sonic effect might deal sonic damage.