Noise is defined as unwanted and annoying sound. It is measured in decibel or db. The acceptable noise standard is 80 db noise levels for 8 hours per day, 90 db of noises for 4 hours per day or 100 db of noise for 1 hour per day etc.Hence permissible noise is dependent upon the time of exposure. More the intensity, there is less time of exposure. When the intensity exceeds permissible level it causes noise pollution. It affects both physiologically und neurologic ally and in extreme case, there is impaired hearing of either temporary or permanently.Average noise in a city-life is 70 db. Motor-truck creates noise of 80 db. The intensity of 120 db is painful limit to ear.Government's offices, major installations and displaced people have been settled to the new town. But the large counts of displaced population say that they are still waiting for the compensation; they have been told about.Environmentalist's Protest:Tehri dam is a gigantic multipurpose project. The dam has been surrounded by controversy since it's very inception. The Tehri Bandh Virondhi Sangrash Samiti was formed as soon as the project implementation was started and people were threatened with displacement. The Cipko Movement, led by Shri Sundarlal Bahuguna, started a campaign to save the Ganga and Himalaya. Chipko activists intensified their struggle to save the Ganga from the hazards of Tehri Dam after a disastrous earthquake hit the Garhwal region on October 20, 1991. The protestors were arrested on 27th Feb, 1992. Subsequently Shri Sundarlal Bahuguna went on a 45 day fast.The main reasons why the citizens of Tehri Garhwal, several scientists and ecologists have opposed the Tehri dam are the following:(i) The uprooting of more than one lakh people from their homes in Tehri town and surroundings villages. Only a very small percentage of population to be displaced has been resettled so far.(ii) The high risk of dam failure, whether by an earthquake of higher intensity than what the design provides for, or by other factors such as overtopping and erosion of hillsides into the reservoir. In the case of such an event the acute threat to dense urban and rural habitations in the down-stream areas, including the culturally important towns of Dev Prayag, Rishikesh and Hardwar.(iii) The threat of reservoir induced siesmicity (RIS), after the creation of the huge new artificial reservoir, to the people living around this reservoir, a threat that arise from the height of the dam and other factors favorable to RIS found at and around the dam site.(iv) Some experts assess the threat of rapid siltation of reservoirs due to the high erosion in the catchment areas, the present life of the reservoir at only 60 years.(v) The project has been steeped in financial waste and corruption. The Comptroller and Auditor General have raised disturbing questions about this project. The collapse of the Soviet Union has also put the project in financial crisis since the project was being financed with Soviet aid.(vi) Adverse impact on fisheries, other fauna and flora, and various other adverse effects.It is important to stress that each of these adverse effects have been sufficiently confirmed and stressed by experts and by the government from time to time to inquire into the project due to its controversial nature. The opposition to the project is not based just on the basis of the understanding of social activists; it has also been questioned by the government appointed experts.