Today on May 7, 2012, in English For IT II I learned about Noise, and the following is a summary :
Although noise, generally defined as unwanted sound, is a widely recognized form of pollution, it is very difficult to measure because of the discomfort experienced by different individuals is highly subjective and therefore variable. Exposure to low levels of noise may be a little mimic, whereas exposure to higher levels can actually cause hearing loss. Unlike the eye, which can be covered by the eyelid against strong light, the ear has not closed, and therefore, always open and vulnerable; noise penetrates without protection.
Noise causes hearing effects can not control and where the body never becomes accustomed. Loud voice instinctively danger signal for any organism with the hearing mechanism. Function of the improvement brought about by a rush of adrenaline is released in response to fear, and some of these responses lasted for thirty minutes after the sound has stopped.
Because noise is unavoidable we continue to consider this a dangerous thing. It may be a serious threat to the physical and psychological health. Hearing loss is the number one problem in America and affect the heart. Psychological effects of noise is very important. Restlessness, irritability, tension and anxiety increased, affecting the quality of rest during sleep, and the way we interact.