Related Clues:

• "Listen!"
• Bid for attention
• 'May I interrupt?'
• Word of greeting
• Tripled, Yogi Bear's catchphrase
• 'If I may interrupt, ...'
• "Yo!"
• "Watch it!"
• With 53-Across, a Beatles song
• 'Howdy!'
• Cutting-in noise
• "Get your hands off me!"
• 'Pardon me...'
• Throaty interjection
• "You there!"