Related Clues:
- Low-volume talk
- Buzz; stink
- Odds raised, which brings complaint
- Muttering
- Mumbled expression of malcontent
- Indistinct sound
- Well-tuned engine output
- Subdued complaint as alcoholic double upended
- Coo
- Sing with mouth closed
- Drone or buzz
- Vibration sound
- Operate smoothly
- Bad stethoscope sound
- Rumour of spirit being rejected twice