Related Clues:

• Trumpeter's device
• All clammed up
• Like the "h" in honor
• Soundless
• Silence the tube
• Instrumental silencer
• Soft-pedal
• Remote control?
• "Turn off the sound" button
• Not saying a thing
• Sound-killing button
• Like many old movies
• Make less flamboyant
• Unexpressed but understood
• Instrumental muffler