通常认为只有声级较高的噪声才会对周围环境造成污染,而对低噪声产生的不利影响还没有引起足够重视。事实上,在城市的许多环境中,等效声级低于国家标准的噪声,更能引发受声者较强的烦恼,甚至身体方面的不适。 It is generally considered that only high-level noise can pollute the environment, while the adverse effect of low noise has not been given enough attention. In fact, in many urban environments, the equivalent sound level is lower than the noise of national standards, which can even cause strong disturbances of the sound receiver and even physical discomfort.