Reaction of people for urban noise under heterogeneous traffic conditions

In Indian sub continent the occurrence of high noise levels is a common cause of concern. In a study conducted by authors it has been found that peoples reaction vary from region to region even inside the country. Noise levels (Leq) have been measured in residential and commercial areas using a norsonic sound level meter. Subsequently the subjective reaction of people has been evaluated through a questionnaire. The relationship Lden verses % HA (highly annoyed) has been studied in this case. It is observed that people tolerance towards noise (Lden) tends to increase due to habituation. When compared with other authors in the literature, it has been observed that Indian subjects are more tolerant for Lden levels of less than 70 dB and the tolerant levels decrease beyond Lden of 70dB. One significant source of noise is the horn sound as revealed in the survey. Further in this study two predictive models are developed to find %HA with respect to Indian conditions. For better visualization of % HA group, the figures are mapped over the area studied by using the soundplan software.