[Evaluation of noise pollution in crowded areas in Yasuj in 2006]

Human exposure to environmental noise increases day to day and noise is currently a very important stressful factor. One of the common sources of noise is transportation vehicles. Undesirable impacts of traffic persuaded governments to set rules for the problem and when civil planners and road engineers decide to construct highways, they must be sure that the related standards and rules have been met. The aim of this study was to evaluate the rate of noise pollution in crowded areas of Yasuj. Noise measuring was done by using B and K Sound Level Meter [model 2230]. Noise descriptors [Leq, Max, Min] were measured for 10 minutes of any hour during daytime and night in selected areas [11 stations]. One station was also selected as reference point and noise measurement was carried out for the whole week in this station. Leq was found to be 72 +/- 4.4 dB [Max] and 65.4 +/- 7 dB [Min]. Recorded maximum and minimum noise was 99.7 dB [at 17-18 o'clock] and 34 dB [at 4-5 o'clock], respectively. Comparing the findings of this study with standard scales indicates that Yasuj is experiencing high noise pollution

Noise pollution in residential areas of Jharsuguda Town, Orissa (India) and its impact.

In this paper, an attempt has been made to study noise levels in different residential areas of Jharsuguda town in western Orissa (India). Minimum, maximum, L10, L50 and L90 noise levels have been computed. It was found that noise levels in the residential areas exceed the standards set by the Central Pollution Control Board, India. Vehicular traffic, with air horns of loud noise, was found to be the main reason for these high noise levels. Strict measures need to be taken to reduce and control the noise pollution.

Noise control in the transportation corridor.

This paper considers the opportunities for noise control within the route corridor required for construction of road, rail and other guided transport schemes. It deals with control of noise generation at source, and in the transmission path close to the point of generation. In this way it is possible to control the amount of acoustic power generated, and to absorb part of the radiated power at points of reflection. Purely reflective wayside barriers do little to absorb acoustic energy, merely reflecting it in a different direction. Whilst this has selfish benefits to the receptor in the shadow zone of the barrier, it makes things worse for others on the reflective side of the geometry. The paper therefore considers the options available to the engineer in the design of rolling and sliding interfaces and the use of acoustically absorptive finishes on all surfaces close to the point of noise generation. This includes the running surface itself, structural components, retaining walls, over and under passes, and the inner surfaces of track and wayside barriers.