Feline's Hammegaphone

Every day, Feline does her singing exercises on the bridge of her ice prisoner boat, the Glass Heart, using her Hammegaphone. Little does she know, that's what keeps her safe from the region's monsters: the sound of Feline's amplified voice is so unbearable that all living creatures for kilokametres around run away and never come back. Only her husband, Rayné, stays. He's been a bit hard of hearing for quite a while, though. (Place this hammer over another, already-equipped hammer to change its appearance.)