Acoustic insulation reduces the amount of noise that workers hear. It’s used inside engine bays, mobile equipment cabs, and machine enclosures. All sound insulation isn’t the same, and there are some misconceptions about the nature of noise. By understanding a few basics, however, you can begin to find the right solutions for industrial noise control.

Here are five facts to know about noise.

  • Noise is more than a nuisance. It’s a risk that carries costs.
  • Pay attention to the path. The way sound travels may surprise you.
  • Doubling the noise reduction may not cut the sound power in half.
  • Decibel-level differences between sources drive perceptions of sound.
  • Custom-fabricated acoustic insulation improves industrial noise control.

Let’s take a closer look.

Noise is more than a nuisance. It’s a risk that carries costs.

Noise can make it hard to hear beeps, buzzers, and alarms from machinery and equipment. Loud sounds can also impede concentration and limit employee communications. Violating industrial noise standards can result in fines and penalties, but the problem doesn’t end there. Sound-induced vibrations can cause structural fatigue and stress concentrations that cause parts, assemblies, and equipment to fail.

Pay attention to the path. The way sound travels may surprise you.

Noise is a pressure wave that travels from a source through a medium to a receiver. In mobile equipment where the operator sits above the engine bay, sound-induced vibrations can travel from the engine (the source) through a body panel (the medium) and cause a windshield to rattle. Yet the equipment operator (the receiver) may blame the rattling on noise that’s coming from the engine through the floor.   

Doubling the noise reduction may not cut the sound power in half.

The human ear detects variations in pressure caused by sound waves. The amplitude of this variation, the noise level, is measured in decibels (dB). Sound pressure level (SPL), a sound power measurement, uses a logarithmic scale where the reference is the threshold of hearing. As the following table shows, dB reductions and the corresponding SPL percentages might not be what you expect.

If you reduce the noise level by

You’ll reduce the sound power by

1 dB

21%

3 dB

50%

10 dB

90%

20 dB

99%

Decibel-level differences between sources drive perceptions of sound.

Decibel-level differences between noise sources can also affect total noise levels in unexpected ways. Consider the example of two machines running in the same room. Each machine has a current noise level of 90 dbA, a decibel-driven unit of measure for the relative loudness of sounds in air. Machine 1 always runs at 90 dB, but the noise level for Machine 2 increases depending on which operations are performed.

Here’s what happens when Machine 2 runs at 90, 95, and then 100 dBA.   

Machine 1

Machine 2

Total Noise Level

90 dBA

90 dBA

93 dB

90 dBA

95 dBA

96 dB

90 dBA

100 dBA

100 dB

Custom-fabricated insulation improves industrial noise control.

Sound insulation that’s custom-fabricated doesn’t just reduce noise levels. By choosing the right partner, you can also achieve business and technical benefits. At Elasto Proxy, we can recommend the right sound absorbing, sound blocking, and vibration damping materials. To tune-out specific sounds, we can then laminate different materials together into a sandwich-like structure.

At our manufacturing facility near Montreal, we use water jet cutting to create acoustical insulation with specific shapes (including chamfers) and tight tolerances. We can even provide taped insulation for a peel-and-stick solution that’s easy-to-install. Our value-added services include kitting and custom packaging so that your installers have everything they need in the same box – and in the right order.

Would you like to learn more? For samples of our acoustic insulation, ask for the Elasto Bag.

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