Deaf

From HGWiki

Deafness is a status effect that leaves a target unable to hear.

This effect causes a 20% spell failure rate to occur when casting arcane spells. Though counterintuitive, this can be bypassed by using Metamagic: Still Spell.

A target who is deafened cannot benefit from the effects of Bard Song.

Deafened creatures are able to make successful listen checks, despite the apparent contradiction.