Noise levels in Chennai consistently exceeded prescribed limits, finds IIT-M study

A noise mapping study done in the city has revealed that noise measurements in certain areas consistently revealed exceedance of standards set by the Central Pollution Control Board (CPCB) in residential and sensitive zones, with values at several locations surpassing permissible thresholds. Traffic was identified as the primary contributor to urban noise pollution in the city.

The study, released at the Tamil Nadu Climate Summit 4.0 on Tuesday, found that the highest noise levels were consistently observed in Ambattur and Valasaravakkam, both of which are characterised by dense traffic corridors and intense urban activity. It was conducted from March to December 2025.

By contrast, the lowest values were recorded in Manali and Adyar, where traffic volumes and commercial intensity are relatively lower. Additionally, low levels were also noted in Thiru. Vi. Ka. Nagar, and Alandur, suggesting that residential layouts and land-use characteristics provide some acoustic relief in these areas.

Under the prescribed standards, the permissible ambient noise limits (in dB(A) Leq) are 75 during the day and 70 at night for industrial areas; 65 during the day and 55 at night for commercial areas; 55 during the day and 45 at night for residential areas; and 50 during the day and 40 at night for silence zones.

In Ambattur, all 3,508 daytime and 1,770 night-time residential observations recorded exceedances — a full 100 per cent non-compliance. The same pattern was seen in Valasaravakkam, where all 3,354 daytime and 1,686 night-time residential readings breached permissible limits.

Traffic locations also showed significant violations. In Valasaravakkam, 2,674 of 3,183 daytime traffic observations (84.01 per cent) and 1,470 of 1,606 night-time readings (91.53 per cent) exceeded standards. 

In Teynampet, 2,988 of 3,170 daytime traffic observations (94.26 %) and 1,572 of 1,585 night-time readings (99.18 %) were above limits. 

Shiv Nagendra S.M., Department of Civil Engineering, IIT Madras, said that noise limits differ depending on the zone. “One of the reasons we did this study was to identify the specific sources of noise and develop targeted plans to address noise pollution in the city. Beyond commercial activity, there are multiple contributors, so it is important to understand the characteristics of the noise, particularly if it is traffic-specific,” he said.

To represent the different contributors of noise, the study also looked at ‘traffic’ and ‘sensitive’ zones, in addition to the four defined by CPCB – residential, industrial, silence, and commercial zones – to better map areas.

The study recommended that in the long term, strengthening Chennai’s noise management practices must go beyond isolated mitigation measures and be embedded within broader urban and transport planning frameworks. The adoption of people-centric urban models offers a sustainable pathway to reduce dependence on private vehicles, reclaim public space, and lower environmental noise levels.