The Just Noticeable Threshold is the amount something must be changed in order for a difference to be noticeable. When this difference is detectable at least half of the time is called Absolute Threshold. This concept has been redefined, it was originally considered as the lowest level of a stimulus, but now is the level at which a stimulus will be detected a specified percentage (50%) of the time.
. Go green by planning trees . Turn off appliances at home and office when not in use . Stay away from noisy area . Educate friends and neighbours about hazards of noise