Related Clues:

• Runs smoothly
• Massage reactions, perhaps
• Contented sounds
• Sounds from the hot tub
• Sighs of contentment
• Cries at a circus
• Satisfied sounds
• Satisfied sighs
• Spa sounds
• Hums like an engine
• Oohs' partners
• Sounds of pleasure
• Contented sighs
• Responses to a doctor
• Open-mouth sounds