Related Clues:

• Stevie Wonder's Ellington tribute "___ Duke"
• Low-key "Hey!"
• Sibilant "Ahem!"
• "Over here!" sound
• "Dear ___ or Madam"
• Attention-getting noise
• What to call a sergeant, perhaps
• Title for a Brit
• Patrick Stewart, as of 2010
• Common honorific
• It's attention-getting
• Anthony Hopkins, for one
• It may precede "Over here!"
• Follower of yes or no
• Sound before "Yeah, you!"