During a speech about space exploration at the John F. Kennedy Space Center in Florida, the president of the United States declared, “Fifty years after the creation of NASA, . . . Our goal is . . . to live safely beyond the Earth for extended periods of time, ultimately in ways that are more sustainable and even indefinite” (Chenes 14). Along with many other American citizens, the president himself believes in exploring and conquering the space frontier. Many citizens and people across the world
unwanted sound but this is subjective definition as one man’s sound may be another man’s noise.1 Physically there is no distinction between sound and noise. Sound is a sensory perception and the complex pattern of sound waves is labeled noise, music, speech etc. Environmental noise is a common cause of hearing loss in industrialized societies. When the noise exposure causing hearing loss is present in the workplace, it is referred to as occupational noise induced hearing loss (NIHL). Community noise