• By modifying the source to reduce its noise output
• By altering the transmission path to reduce the noise level reaching the listener
• By altering the receiver's exposure either through limiting the exposure time or by providing personal protective equipment (11)

Noise output can be reduced by

• Reducing impact or impulsive forces
• Reducing speed in machines, and flow velocities and pressures in fluid systems
• Balancing rotating parts
• Reducing frictional resistance
• Isolating vibrating elements within the machine
• Reducing noise radiating areas
• Applying vibration damping materials
• Reducing noise leakage from the interior of the machine

Noise transmission paths can be altered by:

• Separating the noise source and receiver as much as possible
• Using sound absorbing materials
• Using sound barriers or deflectors
• Using acoustical linings
• Using mufflers, silencers, or snubbers
• Using vibration isolators and flexible couplers