Many research and data compilations have shown that not just the carbon foot print but the Noise pollutions world over have increased substantially in the past 3 decades, while we have less cry over the increasing Noise levels in our daily routines, the damages are nothing less severe.
Some years back, we had an assignment from the Bangalore's police department for monitoring and quantifying the existing noise levels in one of the CBD road where the Metro train via-duct line was proposed. The scope also included predicting the impact of Metro rail operations on the overall increase to the Noise levels to the road users and adjoining the establishments. While the Leq values showed a great contribution from the honking addiction, the base noise (as much without honking) showed far reasonable levels, both for the day and night segments.
Upon modelling the proposed via-duct and the train induced noise over the mid-section of the road, two surprising facts were revealed, firstly, the metro rail movement itself did not contribute much to the already existing noise on the road, at least for the day segment; but the model indicated that the Noise level has definitely increased due to reflections from the concrete "roof" throwing back as much as 4 to 5dB to add to the road / traffic induced Noise !! this problem was further compounded by the thick glass facades of the shops / establishments alongside the road that were helping the noise to "STAY" for longer periods.
A verification study post metro rail operations, confirmed the above facts beyond doubts.
Extrapolating this scenario to other even more cramped cities across the world, we get to understand how much are we subjected to Noise pollution and their impending effects on our health; the high concretization of our urban spaces and lowered natural green cover, ever increasing traffic density have all put the exposure to high doses of noise considerably.
Many of us are already aware of the ill effects of Noise exposure, while we tend to cover our personal spaces (including using noise cancellation headphones), covering houses and living spaces with noise isolations, the public noise scenario is far more serious and compelling