抄録
In daily life a person may on occasion find him or herself annoyed by music, speech or the noise of pets, etc. , originating at home or with one's neighbors even though the level of the noise is relatively low as compared with the noise from a factory or an airport. The purpose of the experiments described in this paper is to determine under what conditions these low level noises, e. g. , music, speech, etc. , constitute annoyance. In the first experiment (Exp. 1) the detectability and recognition threshold of three noise sources (i. e. , piano, speech, barking dog) is measured against a broad spectrum background noise of various A-weighted sound pressure levels (25 and 45dB). In experiment 2 the subjects are engaged in a mental task (simple math divition) while exposed to various low level noises and are asked to fill out a questionnaire designed to determine the degree of annoyance the noises posed and whether or not the noises hampered the performance of the task given. It may be concluded that; (a) a source of noise can be identified even though of a lower level than the background noise; (b) even though of relatively low level, a particular noise triggers annoyance in some individuals while having no effect in orders; (c) the degree of annoyance or hinderance of a task does not necessarily correspond to the level of the noise; (d) the degree of annoyance corresponds to the degree of recognition of the noise source; (e) individual responses vary greatly implying the subjective meaning of the noise plays major role in evaluating the annoyance factor of the noise.
