Related Clues:

• Audio feedback problem
• Twice-heard sound
• Grotto sound
• Bouncing sound
• Cave phenomenon
• Stairwell sound effect
• ''Hello'' again?
• Yodel recall?
• Agree with
• Voice agreement with
• Bounced response
• It may be heard in a tunnel
• Empty-hall sound
• Return from the cave?
• Draw forth, as memories