The influence of the visibility of the source on the subjective annoyance due to its noise

The definition of noise annoyance used in this paper, is that, in a certain acoustic environment, the negative subjective response including distraction, disturbance, displeasure and anxiety can be described as noise annoyance. We choose two types of typical areas where the characteristic of the acoustic environment are similar to study the influence of the visibility of the source of noise (whether the source of noise can be seen or not) on noise annoyance. In our research, the degree of noise annoyance is divided into five grades according to previous international research: "not at all," "slightly," "moderately,". "very" and "extremely", they are typical fuzzy description. The appraisal of subjective annoying response is a fuzzy event. So the fuzzy mathematic method is applied to calculate the probability of noise annoyance to evaluate the influence of the visibility of the source on an individual's degree of subjective noise annoyance. The conclusion shows that under the same acoustic environment, when the source of noise can be seen the corresponding noise annoyance is higher, this finding will furnish us with a new approach in the research of the noise control. (C) 2003 Elsevier Ltd. All rights reserved.