Related Clues:

• Is open-mouthed, needing oxygen, say, to take exercise
• Reacts in horror as it's included in navigational tool
• Sharp intakes
• Breaths you can hear
• Sounds of astonishment
• What singer does off drum riser
• Pants son's wearing split more than once
• Horror-ible reactions?
• Sounds shocked
• Draws breath sharply
• Some checkers moves
• Expressions of amazement
• Shows shock, in a way
• Clears a hurdle
• Signs of shock