Related Clues:

• Sound from Catwoman
• "Dinger" or "drum" starter
• Smooth-running engine sound
• Desirable engine sound
• Sound engine sound
• U2 album "Rattle and ___"
• U2 album 'Rattle and ___'
• Music to a cat lover's ears
• Work smoothly
• Kitten noise
• Accompany musically, maybe
• Indistinct murmur
• Motor noise
• Sound from a contented cat
• Siamese sign of contentment