noise
Noise from the physical point of view, is the sound wave frequency, strength changes irregular, chaotic voice. Noise is a physical or psychological feel uncomfortable, generally let people who hear it unhappy, uncomfortable, unwanted, or annoying, unpopular sound, affecting people talking or thinking, working and learning The sound of rest. In general, people use decibels (dB) to measure the intensity of noise, with the signal to noise ratio (S / N) to measure the impact of noise on the useful signal. The possible sources of noise are aircraft, cars, factories, construction sites, daily life and so on. Noise is one of the environmental pollution, governments generally have the appropriate laws to regulate the control of noise. ...