Statistical structures of indoor traffic noise in a high-rise city

Noise measurements were conducted in seven residential flats close to the t raffic in Hong Kong. Noise-level time variations and their statistics are d iscussed. The results of the overall noise level statistics reveal that Gau ssian noise-level distribution can only be. found under the free traffic-fl ow condition while some characteristics of gamma noise-level distributions are observed when the flow is: of the interrupted type. Short-duration nois e-level time variation statistics reveal a well-defined relationship betwee n skewness and kurtosis for each traffic-flow pattern identified. Results a lso suggest that the Pearson type I and IV distributions are useful for des cribing the short-duration noise-level distributions. (C) 1999 Acoustical S ociety of Amer ica. [S0001-4966(99)00512-3].