Related Clues:

• Acts contentedly
• Sounds from a Siamese
• Sounds contented
• Symptoms for a car mechanic
• Doesn't knock?
• Sings without words
• Ambient sounds
• Joins in wordlessly
• Smooth engine sounds
• Abyssinian's sounds
• Cat murmurs
• Betrays contentment
• Sings close-mouthed
• Doesn't ping
• Sings with a closed mouth