Related Clues:

• Machinery sound
• Make a humming noise
• What rotors do
• What helicopter rotors do
• Electric fan noise
• Rotor sound
• Rotation noise
• Machinery noise
• White noise from a fan
• Sound made by helicopter rotors
• Dishwasher sound
• Electric fan sound
• Blender blade's sound
• Helicopter rotor sound
• Drone from a drone