You can use enclosures fitted around all or part of the machine to reduce noise.

What type of enclosures are there?

How effective are acoustic enclosures?

The amount of noise levels you can reduce using barriers or enclosures depends on:

• the noise source
• the materials used to create the barrier or enclosure
• the acoustic environment on either side of the barrier
• how the barrier is set up.

An effective noise barrier has good transmission loss (TL). TL is the amount a certain material will reduce noise as it travels through the material.  The TL increases with the frequency of sound levels. Single wall barriers can reduce hazardous noise levels by 2 to 5dB for low frequency sounds, and 10 to 15dB for high frequency sounds.

There are some simple ways you can make your enclosure more effective at reducing noise:

• Setting up a two or three sided enclosure can reduce noise levels by 30dB for higher frequencies.
• Choose materials that provide higher noise reduction. Materials that are compact, dense and heavy are more effective. For example, plasterboard and hollow concrete are more effective than chipboard.
• Even the smallest air gap can affect how well a barrier blocks sound. Check pipes, electrical wiring and hydraulics are fully sealed. If you can’t reduce gaps, line the piping with a sound absorbing material to minimise the amount of noise that escapes.
• Seal all windows, doors and hatches.
• Use double or triple glazing.
• Line walkways or tunnels with sound absorbent material to minimise noise escaping when doors are opened.
• If possible, workers should be able to operate the machine around the enclosure to limit exposure to hazardous noise levels.

Engage with workers who use the noisy machine or equipment when designing your enclosure. They can help you understand which parts of the machine they need to access, so you can design the enclosure around the access points. 

Who can install enclosures?

Builders and carpenters can install the enclosure for your machine. Always seek advice from an acoustic engineer about which sound absorbing material to use that will achieve the best noise reduction for your machine.