Related Clues:

• Kettle sound
• Radiator sound
• Leaky radiator sound
• Sound of a leak
• Flat sound
• Flat tire indicator
• Air hose sound
• What a balloonist hates to hear
• Sound of a slow leak
• Flat sound?
• Asp's sibilance
• Scary sound for a balloonist
• Frightening sound for a balloonist
• Leak sound
• Sound of air escaping