Related Clues:

• 49-Across setting
• Match setting
• Unoriginal response
• Tinkle in a phone booth
• Sound for a spelunker
• Pug's place
• Letter after delta
• It may bounce off the wall
• Gymnasium sound
• Bounce in a cave
• Narcissus spurned her
• Key holder
• Band at a wedding
• Guitar effect
• It's often tested by shouting 'Hello!'