Noise walls, which appear over thousands of highway miles, have their roots in the iconic Hollywood Bowl that opened in 1922.
Construction of the Hollywood Bowl didn’t inspire noise wall innovations. Local residents and audiences at different events complained about nearby highway noise.
A Medium article details some of the origins: “Acoustical physicist and UCLA professor Dr. Vern O. Knudsen would recommend in a 1945 study that ‘a wall or parapet, built to a height of at least 10 feet above the promenade walk, be constructed along the southeast corner of the Bowl, thus enclosing the entire seating area with a substantial wall which will serve as a sound screen against street and Freeway traffic noises.’ ”
As highways were built, more people were annoyed with noise levels from traffic. In the late 1950’s, the California Department of Public Works asked researchers to conduct an acoustical study. Ultimately, the first sound wall was erected in 1968 along part of Interstate 680 in Milpitas, California (near San Jose).
The progress in California gave rise to many other case studies and studies well into the 1970’s (fueled, in part, by regulations related to the U.S. National Environmental Policy Act). Noise wall design interest gained momentum after the Noise Control Act of 1972. Federal highway standards require noise walls to be visually appealing and “designed to preserve aesthetic values and scenic vistas.”
Sound walls (also known as sound berms, sound barriers, or acoustical barriers) reduce noise levels for people living next to highways by absorbing sound energy or by reflecting sound energy.
Precast concrete sound walls can be designed to blend in with a city's architecture and local topography, or even to capture a community's theme or identity. Reflective noise barriers can reduce noise by as much as half while absorptive treatments have been found to further reduce noise pollution.
With color additives or stains and textured form liners, the options are nearly endless. Learn more about how we construct noise walls at Mack Industries.
Sound walls are available in many diverse shapes and sizes. The applications go way beyond the high walls along highways. Examples include:
Electrical substations and transformers
Wastewater treatment plants
Precast concrete is the material of choice for sound walls because of its durability, flexibility, ease of installation, environmental friendliness, and wide range of aesthetically pleasing designs. Precast concrete performs well even in harsh environments.
Noise walls benefit residents in different ways:
Better night’s sleep
Improved setting for outdoor activities
Less exposure to noise that could impair hearing
For more information about noise walls and other products, contact Mack today or call (800) 482-3111.