Explanation

Human hear can hear a frequency of 500 to 5000 hertz, , sound energy is measured in terms of units called decibel(dB). Sound in our city homes (silent zone) during day time averages 40-50 dB, but street noise average 70-80 dB. Sounds upto 80 dB are considered bearable by man, but higher sound intensity are hazardous, causing nervous stress, irritability, increased blood pressure, etc.