Engineering Solutions to Acoustic Problems

Environmental Assessments/Impact Studies

One way or another sound gets transmitted outside. Once it is outside it can have numerous affects. It can cause annoyance to a nearby neighborhood, interference with communication at a school or disturbance with sleep in an abutter's home. Regulations on federal, state and local levels abound and vary depending on where you live. NCE offers assessment and interpretation of these regulations for both the noise generator and abutters to noisy facilities.

Services offered to manufacturing facilities, community groups, municipalities and anyone with critical exterior sound problem are:

A background noise survey is one where the existing sound levels are measured. For an abutter to a loud factory this would be a method to quantify the levels of noise around the property. For the factory operator, such surveys are typically conducted during a period when the factory is both operating and shut down. These surveys are usually conducted with a logging sound level meter which is left in place for periods of 24 hours to 2 weeks. Background sound surveys are required in order to assess compliance with some noise ordinances and can also be the starting point for environmental impact assessments.

Many noise ordinances require technical assistance in order to determine if a violation occurs. Simple sound levels meters usually measure only "A-weighted" sound pressure levels. While these devices may not meet industry standards and may not stand up in court, they can serve the individual as a quick tool to determine how loud it is. Many noise ordinances have other requirements which cannot be measured with simple sound level meters. These cases include ordinances which have: tonal requirements, octave band noise limits or C-weighted sound levels. In particular, the Massachusetts state noise ordinance (310 CMR 7.10) allows no more than 10 dB greater than the background noise level. This requires accurate measurement of background sound as described above. NCE can help with all these situations as we have sophisticated instruments which can measure all the types of sound levels used in regulation.

Design of a new building, factory or facility of any kind requires all types of assessments. Many municipalities have required noise studies to determine what if any noise impacts will occur. It is a good practice to design-in the noise control treatments into a new facility, as it is generally ten times more expensive to add the noise control treatments after the facility is constructed. NCE has very large database of noise levels from various types of machinery. NCE can predict property line noise levels from new facility blue-prints using our database of noise levels and/or noise estimation algorithms. NCE can provide written assessments of environmental impact from sound and then make recommendations for mitigation.