NOISE PERCEPTION AND SCORING OF NOISE EXPOSURE

Based on the strategic noise maps according to 2002/49/EC, action plans shall be developed to reduce the noise exposure in European agglomerations. To decide among possible alternatives, it is necessary to rank them with respect to noise reduction and number of people exposed. Different strategies have been used to derive a single number noise score. The most often used approach is to estimate the number of Highly Annoyed (HA), because the dependence of the percentage of HA from the exposure can be investigated by scientific evidence. It is shown that this concept fails in many cases. If noise exposures change, we must sum up an annoyance quantity for all persons concerned and not only count the number of persons above a threshold. It is postulated that the relative weighting of different grades of annoyance is a political decision and should be defined taking into account the communities opinion about the best acceptable distribution of unavoidable hazards. Looking to the expressions used to calculate a single number result for assessing noise scenarios, it will be shown that the “Highly Annoyed ” expression causes an extremely weak weighting of noise levels – the consequences are often not acceptable. A Noise Score expression taking these findings into account is proposed