PUTTING RUBBER TO THE ROAD: Tires rolling over concrete roads can create loud noises, especially at high speeds. One way to diminish the amount of noise is to add a one-inch thick layer of rubberized asphalt, folding in pieces of rubber ground up to the consistency of coffee grounds. This layer reduces the level of sound made by cars by about 10 decibels, which means that people will perceive the sound as half as loud.
ABOUT HEARING LOSS: Loud sounds stress and can damage the delicate hair cells in the inner ear that convert mechanical vibrations in the air (sound) into the electrical signals that the brain can interpret as sound. If exposed to loud noises for a long time, the hair cells can become permanently damaged and stop working, producing hearing loss. Noise can induce hearing loss in two ways: sudden bursts, such as firearms or fireworks; or continuous exposure to loud noise, such as motorized recreational vehicles, loud sporting events, power tools, farming equipment, or amplified music. When people lose their hearing because of continuous exposure, it depends on how loud the sound was and how often and how long they heard it. It takes repeated exposures over many years to cause a noise-induced hearing loss in both children and adults.
The Acoustical Society of America, the American Society of Civil Engineers, AVS, the Science and Technology Society and the Materials Research Society contributed to the information contained in the TV portion of this report.