noise & Vibration Control
Occupational noise exposure has been linked to a variety of negative health effects by various researchers around the world. Occupational noise induced hearing loss (NIHL) is the most prevalent irreversible industrial disease and noise is the biggest compensable occupational hazard in many countries according to a WHO report.
Levels of employee noise exposure are regulated by ISO-1999:1990 and OSHA (USA), which are imperative to follow by the industries. Almost all the legislation for occupational noise control worldwide states the limiting values of noise exposure between 85 – 90 dB(A) Leq for eight hours exposure, which is based on the guidelines contained in ISO-1999:1990. France, Sweden, Norway, New Zealand and Spain allow 85 dB(A) Leq. These limits are allowed for halving rates of 3 dB(A) and working schedules of eight hours per day. OSHA (USA) allows 90 dB(A) for an eight hour working day, with halving rate of 5 dB(A).
The noise control directive of EC (2003) states the exposure limit of 87 dB(A) Leq for eight hours duration. Control of Noise at Work Regulations 2005 state an exposure limit of 87 dB(A) Leq for eight hours duration in the UK, in line with the EC directive. In India, model rules under the Indian Factories Act of 1948 stipulate a limit of 90 dB(A) for eight hours exposure.
Where unacceptable noise level exposures are identified, studies can be performed to identify possible mitigations. The above facts clearly emphasise the emergent need to address the problem of occupational noise, which will help in finding effective and practically implementable solutions.
We provide followings types of consultancy services for Noise and Vibration controls:
- Noise Control In Building
- Noise & Vibration Control in Industry
- NVH Testing Facilities
- Noise Mapping
Building acoustics and reduction of machinery noise are the ways of Noise and vibration control.
We provide independent, impartial noise and vibration analysis of various machineries, structures, and surrounding environments using a combination of full-scale measurements and theoretical/numerical methods. In that way, we isolate the cause of the problem and evaluate the technical merits of potential solutions.
Where the anticipated sound or vibration levels exceed the design targets, we use our analytical expertise to rank the sources, identify those requiring control measures, and develop a range of options to allow the design team to select the best solution. Sticking to our approach, we always work closely with the manufacturers, suppliers and installers of noise and vibration control products, like silencers, louvers, mufflers, acoustical enclosures, spring isolators and elastomeric pads.
Typical assignments are:
- Evaluation of noise levels at boundaries of existing commercial and industrial facilities with residential areas and at sensitive receivers.
- Evaluation of background noise levels at boundaries and community locations to develop noise acceptability criteria.
- Reviews of community noise codes and zoning codes to identify potential noise criteria and measurement parameters.
- Comparisons of received noise levels to measured background noise levels and to noise criteria contained in community codes.
- Investigations of noise sources contributing to the received noise levels.
- Investigations of potential noise mitigations.
- Development of computerized noise assessment models to:
- Assess noise emissions from existing and planned facilities,
- Characterize potential noise impacts,
- Identify prominent noise sources, and
- Investigate sound attenuation from potential noise mitigation measures.
- Preparation of noise sections of Environmental Impact Studies.
- Follow-up surveys after noise mitigations have been applied.
Noise Control in Buildings
- Layout and location of mechanical and technical equipment spaces
- Construction of walls, floors and ceilings around noisy areas
- Mechanical system noise control design
- Noise criteria recommendations
- Evaluation of noise conditions
Noise and Vibration Control in Industry
- Evaluation of employee noise exposure
- Evaluation of noise levels around machine perimeters and at operator positions
- Identification of prominent noise sources in manufacturing spaces
- Identification of component sources of noise emission on individual machines
- Investigations of machine noise mitigations
- Evaluation of existing noise and vibration levels due to machinery
- Evaluation of anticipated noise levels at the planning stage
- Noise criteria recommendations
- Noise control design for hearing protection and other requirements
- Construction details for noise and vibration control measures
- Evaluation of performance
- Design of noise control equipment
- Follow-up surveys of employee noise exposure and machine noise levels after machine mitigations have been implemented