Related Clues:

• Headache augmenter
• Reasonable
• Discordance
• Harsh sound
• White thing that may be heard?
• Clue for a car mechanic
• It's not in the library often
• Annoying sound
• Sleep preventer
• Justifiable
• Officially authorized
• Really bad music, to the listener
• Librarian's bane
• It's often made to get attention
• Sleep threatener