Related Clues:

• Silence the tube
• Instrumental silencer
• Soft-pedal
• Remote control?
• "Turn off the sound" button
• Library demand
• Not saying a thing
• "Shhh!"
• Sound-killing button
• "Zip it!"
• Make less flamboyant
• Ma
• Unexpressed but understood
• Instrumental muffler
• Unspoken, but implied