什么叫噪音呢（What is noise）.doc

什么叫噪音呢（What is noise） What is noise? In a simple way, we can understand noise by irregular sounds. There are several sources of noise in the city. One is building noise, which is staged. The other is traffic noise, which has a longer duration of noise. The third kind of noise is noise in our lives, such as noise in entertainment, playing mahjong, music, TV, etc.. Among these noises, the most difficult thing to deal with is the noise of the car. The noise of the car can be solved theoretically, and the noise of the living can be solved at the same time. Of course, the low intensity noise can be solved. But for the sound of piling, I can only say that it is difficult to deal with them at the moment. Apart from their limited work hours, we can not always decorate our own homes as a standard for sound insulation in test rooms. First, we must first understand a basic concept: dB, dB SPL is the size of the unit (symbol: dB), the sound pressure of each double pressure magnitude increase of 6 db. 1 dB is just the human ear can hear the sound of 20 decibels of sound, generally speaking, we think it is quiet, of course, generally below 15 dB we can think it belongs to the dead. 20-40 DB is about couples ear murmur. 40-60 decibels belong to our normal conversation voice. More than 60 dB to 70 dB noise range, we can think it is very noisy, and began to damage hearing nerve, 90 decibels will make the hearing loss, and stay at 100-120 DB within the space of a minute, if no accident, human beings have to temporarily deaf (deaf). The car noise ranging from 80-100 DB to a car by 90 dB for example, in one hundred meters, you can still hear the noise of 81 dB (above the standard due to the difference of environment is different, not absolute value). The magnitude of traffic noise is affected by the following factors: 1, the higher the traffic flow near the road, the greater the noise. The main road will certainly be much more noisy than the municipal road. 2, the higher the speed near