Related Clues:

• Sonic comeback
• It returns your calls
• Lingering sound effect
• ''Is there an ___ in here?''
• Eerie cave effect
• Return to sender?
• Cave effect
• Alpine feedback
• Audio feedback problem
• Twice-heard sound
• Grotto sound
• Bouncing sound
• Cave phenomenon
• Stairwell sound effect
• ''Hello'' again?