摘要 : Noise is defined as an unwanted sound. It is considered as a nuisance and a source of health hazard. The noise generated in factories, highways, airports, etc can cause temporary or permanent hearing damage. Hence it is necessary ... 展开 Noise is defined as an unwanted sound. It is considered as a nuisance and a source of health hazard. The noise generated in factories, highways, airports, etc can cause temporary or permanent hearing damage. Hence it is necessary to protect human working in such situations. Noise control is effected by suppressing the noise level at its source, or path or receiving end. The pre-requisite for all such activities is the assessment of the magnitude of noise level by subjective or objective methods. Almost all nations have enacted legislations specifying the allowable noise levels at various locations. This article reviews the purpose, techniques and applications in noise measurements. 收起