There are 3 major ways to mitigate industrial noise

1. Modifications at the source of sound and vibration
2. Create barriers or improve existing insulation in the path of the noise or vibration, examples isolation vibration mounts, noise enclosure, silencers or attenuators, screen, noise barrier, acoustic louvres
3. Improve the noise or vibration insulation at the receiver, noise cancellation doors and windows, improve insulation of light wall panels with specially designed mass load vinyl

• Sound source info, preferably noise levels at a certain distance measured in 1/1 or 1/3 octaves in dB
• Required reduction in sound level
• Allowed back-pressure
• Medium that will flow through the silencer or sound attenuator, i.e. flow rate, temperature, density etc.
• Requirements for the material of the silencer or sound attenuator

• Always make sure that the existing noise situation is properly documented and measured by calibrated instruments
• Specify the points where should noise should be measured after the noise mitigation has been installed and the Decibel levels for each location, don’t forget to specify if the values are in dB or dB(A) (this can be a huge difference)
• Make sure that payment terms are so that you don’t need to pay the final payment installation if the goals aren’t reached

• YES, employers have the duty to protect workers against excessive noise, typically a limit of 85 dB(A) is allowed over an 8 hour working day, in many countries this level is adjusted to 80 dB(A)
• If noise mitigation is excessively expensive or impossible then hearing protection should be worn, it should be clearly indicated at which areas in a factory hearing protection should be worn, safety department should enforce this
• Employers that have a noisy workplace should let all workers undergo a yearly audio-metric test to make sure the hearing of the workers doesn’t deteriorate more than for average persons that not work in a noisy environment