A room no larger than a 20 ft (6.1 m) cube could be enchanted to emit shrill shrieks and wails whenever a creature larger than a typical rat (3 lb/1.4 kg or 0.5 ft3/0.014 m3) entered. The sonic attack was only heard inside the room and for the first minute was only a warning, allowing the subject to leave the room or protect their hearing organs. After that, the sonic intensity increased for a few minutes before falling silent, deafening all in the room for a few hours, making them easier to surprise and reducing the ability of spellcasters to speak the verbal components of spells correctly. Tougher creatures were not deafened, but merely stunned for a few minutes. There was no way to resist the spell itself, but hearing protection or things like silence, 15' radius prevented the sonic energy from reaching the ears.