Industrial noise is usually considered mainly from the point of view of environmental health and safety, rather than nuisance, as sustained exposure can cause permanent hearing damage. Equipment used in a factory can be extremely loud. Everything from rotors, gears, fans, chillers, internal combustion engines, pumps, heavy machinery, etc., can be seen in industrial settings. All of this equipment can produce noise at decibel levels high enough to create environmental health and safety concerns.
Measures for controlling industrial noise are necessary to protect workers. Louder noise can also become a nuisance and may be considered noise pollution, in which case a community may require a company to take action and address it. When dealing with industrial noise mitigation, if possible, the goal is to always control the noise at the source by modifying the equipment itself or replacing it with a quieter model. However, for many companies, this is not always possible. Also, sometimes noise in a factory or industrial setting is the result of many machines running simultaneously.
Previous research has found that workplace noise led to severe health problems and resulted in significant increases in healthcare costs in many companies.
When an industrial operation is seeking compliance with OSHA noise regulations, the sound level regulation is a function of both sound level and daily exposure time. If the measurements reveal an excessive combination of sound levels and exposure times, a noise problem exists.
Depending on your budget and in-house capabilities, to find out whether you have a noise problem:
• It’s is always best to have an Industrial Hygienist identify the source of the noise and perform a noise measurement using proper instrumentation. Once you have their report, it can be given to a noise abatement company such as Acoustiblok who can help you find a solution using their soundproofing materials. If this is not an option:
• You can purchase a sound level meter, research how sound is measured and what the decibel levels mean, perform your own tests, and compare the results with OSHA noise workplace standards. If outdoor, also compare with your local city noise ordinance noise levels. If this is not possible:
• Another method is to try to talk comfortably with someone about 3.28 feet away (1 meter) from the noise source. If you can, there is probably not enough plant noise at that position to damage hearing. But if you, or others, must raise your voice above normal conversation levels (about 70 decibels) or shout to be heard or understood at close distances (between .6 foot to 1.3 feet (20 to 40 cm), plant noise at that position probably can cause hearing loss and you should have the sound levels there measured with suitable instruments.
• If you are certain you have a noise problem, some soundproofing material companies, like Acoustiblok, have in-house acoustical professionals who will assist you in determining your noise problem and with finding a soundproofing solution.
It’s also important to check noise traveling out of the noisy plant area as well. If personnel in other parts of the plant complain, you should investigate and measure the levels of the sound they hear. If plant neighbors complain, or if local authorities say the sound exceeds applicable noise ordinances, a problem may exist and measurements are called for.
Once A Noise Problem is Identified
Remember that the sound is a form of energy. Your goal therefore is to reduce the amount of sound energy released by the noise source, or divert the flow of (sound) energy away from the receiver, or protect the receiver from the (sound) energy reaching the person. In other words, all noise controls work at the noise source, along the noise path, or at the receiver.
Once you have identified and measured the source of noise, you are ready to consider what can be done to control the noise. When you can’t modify the equipment itself to mitigate the noise, the next best options are to block and absorb the sound using modern soundproofing systems.
The presence of reflecting surfaces (walls, floors, ceilings, and equipment) in an industrial workplace results in the build-up of sound levels in the reverberant field. By controlling the reflected sound (i.e. by preventing the reflections), reverberant field sound levels can be reduced. Generally, the reflections are prevented by use of these acoustically absorbent materials applied directly to wall or ceiling surfaces or suspended from the ceiling.
The key to noise control is finding the control that is both effective and fits your budget. You should know not only what controls can work, but also know how costly the controls are to design and install.
Some acoustical soundproofing companies, like Acoustiblok, use leading noise prediction software, such as DataKustik’s Cadna-A and Cadna-R, to develop acoustical models of the soundproofing solution being proposed before it is purchased and installed for some complex noise problems.