Noise Indicators for Aircraft Noise Monitoring in Vietnam

The day-evening-night level (L_den), the day-night level (L_dn) and the night level (L_night) have been used as noise indicator for noise assessment nationally and internationally. The concrete determination of day, evening and night periods in these noise indicators is very importance since their application directly influence the implementation of the limit value and relevant limit value in other current regulations. This paper reports an attempt to define the time periods of the noise indicators for aircraft noise rating as a part of an international joint project on proposing a manual for aircraft noise monitoring in Vietnam. All data relating to time periods of daily activities and habits of residents aged from 18 years old obtained from socio-acoustic surveys on transportation noise conducted in five cities in Vietnam from 2005 to 2013 was synthesized. The traffic rush hours, bed-time and wake-up time in the southern city are approximately one hour later than those in the northern cities. The people in middle cities have time of rush hour and sleeping start and wakeup in between the northern and southern people. In this study, the appropriate aircraft noise rating indicators for Vietnam would be discussed referring current national and international standards and regulations.