Noise is being considered as pollution many time ago. Now with the help of technology we can try to control it and also to avoid it. Legal restrictions and environmental policies are making this matter works and we are more conscious about the problem itself. Noise has been consistently ranked as a leading cause of neighborhood dissatisfaction. In fact, one-half of the population in cities have felt noise as a major neighborhood problem . In the 1975 survey in states, street noise was mentioned more often than all other unwanted neighborhood conditions. This survey has also shown that aircraft and traffic noise are leading factors in making people want to move from their neighborhoods. Approximately one-third of all the respondents who wished to move because of undesirable neighborhood conditions, did so because of noise. We have here an example of what noise can do to someone, because of that local governments treat the noise as another environmental subject to solve.
             Are people seriously affected by noise?
             The day-night sound level of residential areas should not exceed 55 dB to protect against activity interference and annoyance . It is estimated that well over 100 million people, nearly half the U.S. population, live in areas where the noise exceeds this level . Twelve million people are estimated to live in areas where the outdoor exceeds 70 dB, and they are likely to experience severe annoyance and possible hearing loss. Is hard to measure that around the globe because the legislation about noise pollution is not very strict nowadays, but an approximate idea of it could be like 500 million people are suffering "noise problems" everyday.
             Is the noise pollution an outdoors problem?
             Indoor levels are often comparable to or higher than levels measured outside . However, many outdoor noises still annoy people in their homes more than indoor noises do, and people sometimes turn on indoor sources to mask the...