Related Clues:

• Spa sighs
• Responses to doctors' orders?
• Adult film utterances
• ''I get it'' preceders
• Tongue depressor preludes
• Sounds from depressed patients?
• Sounds contented
• Doesn't knock?
• Tonsil-checking sounds
• Contented sighs (and a homophonic hint to this puzzle's theme)
• ''I get it'' responses
• Blissful sighs
• Magic show reactions
• "So satisfying!" sounds
• They often mean 'I see'