Related Clues:

• "I get it" responses
• Expressions of satisfaction
• Insightful sighs
• Sentence fragments
• Remarks from the relieved
• Contented comments
• 'Ooh' companions
• Physical reactions?
• Sounds of comprehension
• Checkup responses
• Doctors hear a lot of them
• Sounds in a dentist's office
• "I see" sounds
• Oohs and __
• Exam room sounds