barrier lowers the level of noise by building barriers
between the sound source and the sound-receiving point.
Usually, this method is widely used around roads and railroads.
The height and length of the sound barriers are calculated
in consideration of the current state of the sound source
and the sound-receiving point, the degree of the noise
source, the noise criteria of the target area, the installation
influence of noise on the human body depends upon the
strength of the noise. In general, the instantaneous noise
below 60dB does not do direct harm to the hearing sense
of the human body. But the continuous noise above 60dB
may cause insomnia, communication trouble or psychological
instability. The continuous noise above 80dB can cause
serious aftereffects including miscarriage, hearing disorder
and mental disorder. Therefore, the noise-prevention methods
are indispensable as noise occurrence cannot be avoided
in modern society. It is firmly believed that the aluminum
sound barriers will be of greatest assistance in helping
people lead quality lives without occupying a large area
of the road.