Related Clues:

• Rebounding sound
• Radar return
• Canyon answer
• Doter of Narcissus
• 'Can you hear me? ... hear me? ... hear me?'
• Canyon phenomenon
• Audio feedback of a sort
• Radar's effect
• Talk back?
• Sound in a big, empty room
• Hollow response?
• Cavern phenomenon
• Reverb
• Cave sound
• Sound in a cave