Related Clues:

• Rock effect
• Sound for a spelunker
• Letter after delta
• It may bounce off the wall
• Gymnasium sound
• Bounce in a cave
• Narcissus spurned her
• Guitar effect
• It's often tested by shouting 'Hello!'
• Chamber sound
• Benefit of singing in the shower
• Lovelorn nymph
• Me-tooer's response
• Nymph who loved Narcissus
• Reflected radio wave