Related Clues:

• Grotto sound
• Pot holder?
• Bouncing sound
• Cave phenomenon
• Stairwell sound effect
• ''Hello'' again?
• Yodel recall?
• Bounce back again, like a sound
• Agree with
• Voice agreement with
• Bounced response
• Have a lasting effect
• It may be heard in a tunnel
• Empty-hall sound
• Return from the cave?