3445 persons living in Amsterdam (1507 male and 1938 female), aged 41-43 years, participated in an investigation in which the relationship was studied between the (measured) road traffic noise in front of the houses in which the participants lived, and the (reported) resulting annoyance and sleep disturbance. We found a smaller number of persons with annoyance and sleep disturbance than we had expected as a result of other investigations. Considerable differences in the annoyance experience were found for different categories of noise-sensitivity. Furthermore, a negative appreciation of other environmental noises and of the living environment increased the prevalence of traffic noise annoyance. Noise sensitivity and this appreciation are mutually dependent: noise-sensitive people have a greater risk of being annoyed by other sounds (aeroplanes, neighbours, work) as well, and they have less appreciation of their living environment. Noise-sensitivity appears to be more strongly represented amongst persons with a higher socio-economic status. In favour of the point of view that an important contribution to annoyance is of nonacoustic character, is the finding that both annoyance and sleep disturbance are greater amongst people who keep their windows closed at the exposed side of their home.