The average noise level in Singapore is 69 decibels. According to the World Health Organization, if we are consistently exposed to 70 decibels of noise for a full day, we will suffer from hearing impairment. However, this scale is to be interpreted in context for the actual application. For example, how heavy a traffic flow depends on the density of a city and the noise of a normal conversation depends on how loud the surrounding with respect to the person talking is.