Related Clues:

• Librarian's rebuke
• Silence!
• A sound for silence
• 'Stop chewing on that goddamn apple
• Finger-to-lips sound
• 'Put a cork in it!'
• "Quit complaining!"
• 'I'm trying to watch 'The Force Awakens' here, shut up!'
• 'Ahem' subtext, maybe
• When doubled, on the DL
• 'Quit talking!'
• 'Hey, I want to listen here!'
• "Be silent!"
• Sudden silence
• Restraining order of a sort