Related Clues:

• Note passer's signal
• Head-turning sound
• Clandestine call
• Not tune out
• 'Hey, neighbor!'
• ''Wassup!''
• Chipper greeting
• Near-silent 'Hey!'
• 'Hey … you!'
• Hey, the quiet way
• Start of a whispered comment
• "Hey!" in class
• Cry for attention?
• Sibilant attention getter
• Low-key 'Hey!'