Noise Barriers and Noise Abatement Solutions Are Becoming a Necessity
We live in an increasingly noisy world. As population densities increase, buffer space between residences, office parks and recreational public space diminishes. Homes and offices are increasingly built closer to highways and industrial land uses. Often, noisy activities such as construction, roadway traffic and airline traffic are forced into close proximity with these noise-sensitive areas; not even hospitals and schools are spared.
Noise can degrade our quality of life, affect our health, interfere with sleep and adversely affect property values.
Luckily, more architects, construction managers and homeowners are taking proactive steps toward silencing existing noise problems and preventing new problems before lives are disrupted. Once noise levels are known (either by measurement or forecast) today’s planners and architects can minimize the effects of noise on surrounding areas using noise barriers and state-of-the-art sound proofing technology that didn’t exist just 10 years ago.
Noisy neighbors and activities can create unpleasant noise levels in some of the quietest areas. Motorcycles, loud music, late night parties and even home equipment such as heat pumps and air conditioning units can disturb the neighborhood peace and quiet that most of us long for when we’re at home.
Traffic noise is determined by the daily and peak-hour volume of traffic, travel speed, number of lanes, terrain, type of vehicles and the location of the highway in proximity to residential properties, hotels, churches, schools, hospitals, and all locations that require a quiet setting. Noise mitigation on a busy highway or a roadway is often accomplished with a noise barrier designed specifically for this type of setting. Sound abatement window treatments and walls can also be used to reduce noise levels indoors. The FHWA Traffic Noise Model (TNM) is used to analyze and predict traffic noise based specific parameters, and is often used to design adequate noise barriers.
Airliners are loudest on take-off, especially for locations behind and under the departure flight path. Landing aircraft are typically much quieter. The FAA has published the Integrated Noise Model (INM) and Helicopter Noise Model (HNM). These computer models are used to generate noise contours or "footprints" of average noise levels based on the number of operations and aircraft types. Areas exposed to levels above Ldn (Day Night Level) 65 are considered to be "noise impacted,” and nearby homes and buildings would benefit tremendously from noise barriers and other noise abatement solutions.
Light rail train and railroad operations can also raise noise to significant levels. DOT regulations require that a horn or signal at certain sound levels be used at road crossings. Diesel locomotives produce a great deal of low frequency noise. Once the locomotive is past, squealing wheels, air brakes and other track noises remain. Standard FTA methodology is used to predict railway noise, based on number of trains, track conditions, speed, grade, and similar factors.
The noise levels can make living near train or railroad operations unbearable unless the proper sound abatement solutions are put in place. With light rail train construction on the rise across the U.S., planners have begun incorporating noise barrier systems into existing and new train projects wherever noise is a problem.
The U.S. Department of Housing and Urban Development (HUD) and other federal agencies specify acceptable noise levels for residential projects.
For sites exposed to noise above Ldn 60, there is the potential for impact. Sites exposed to outdoor noise up to Ldn 65 are considered “normally acceptable” for residential development. HUD requires a noise study whenever the site is within certain distances of major roads, rail lines or airports. The study must examine both present and future conditions, projected at least ten years out (although twenty years is the standard of practice.)
Noise is fast becoming one of the most pressing public health issues in society today. Noise pollution affects everyone, and long term health projections for people subjected to high noise levels over continuous periods of time are bleak; stress, heart disease, hearing loss and other noise-related maladies are becoming serious problems worldwide. Luckily, there are proven methods of reducing noise and creating healthier living spaces.