The ambient noise standard for residential areas is 55 decibel dB during the day and 45 dB at night. Permissible noise in industrial area is 75 dB in daytime and 70 dB in nighttime. Permissible noise in commercial area is 65 dB in daytime and 55 dB in nighttime. Permissible sound in residential area is 55 dB in daytime and 45 dB in nighttime. Permissible sound in silence zone is 50 dB in daytime and 40 dB in nighttime. Day time shall mean from 6am to 10 pm and nighttime shall mean from 10 pm to 6am. Silence zone are areas up to 100 m around hospitals educational institutions and courts. One can complain to the authorities if the noise levels exceed from the allowable limit by more than 10dB. High noise levels lead to stress related dysregulation of the autonomic system leading to high blood pressure and heart disease.