A REVIEW OF TRAFFIC NOISE STUDIES RELATED TO ENVIRONMENTAL PLANNING

This paper reviews traffic noise studies covering factors relevant to environmental planning for noise. The aspects considered are: (1) traffic noise measurements; (2) studies of noise propagation; (3) the evaluation of the effects of noise on exposed populations. The traffic noise characteristics to be measured include: (1) intensity; (2) spectral composition; (3) random variations with time (noise signature); (4) equivalent sound level (Leq). In India, the first noise surveys were conducted in the 1960s, and led to Indian codes of practice on acoustics, sound insulation and noise control. During the last two decades, vehicle and traffic noise studies have been performed in several major Indian cities. There is a description of the techniques used in India for vehicle and traffic noise measurement. Traffic noise studies aim to relate human responses to noise to physical descriptors of noise such as: (1) traffic noise index; 2) noise pollution level; (3) day and night sound levels. Human responses include: (1) sleep disturbance; (2) interference with speech: (3) annoyance. Other aspects to be considered include propagation of traffic noise, and acoustic criteria for environmental planning.