Noise sensitivity and diminished health: the role of stress-related factors
The concept of noise sensitivity emerged from public health and psychoacoustic research to help explain individual differences in reactions to noise. Noise sensitivity is frequently included as a personality variable in public health studies investigating the influence of environmental noise on health and well-being. Interestingly, noise sensitivity appears to be associated with diminished health, independent of environmental noise exposure. However, the mechanisms underlying the relationship have not been adequately explained. Noise sensitivity has been described as a variable that may increase an individual’s vulnerability to noise and other stressors. Therefore, the association between noise sensitivity and diminished health might be explained by excessive psychological stress and stress-related physiological changes. As such, this thesis addressed an important gap in the literature by examining the role of stress-related factors in the association between noise sensitivity and diminished health.
Two studies were conducted to test the hypothesis that stress and stress-related physiological changes are involved in the association between noise sensitivity and diminished health. Study 1 was a large (n = 1102; 367 males, 713 females aged 18-94 years) survey-based study designed to test a model of noise sensitivity and self-reported health involving measures of subjective health complaints, self-reported hypertension, and mental health complaints (anxiety and depression). Perceived stress and sleep problems were tested as mediators in the model, while gender and environmental noise exposure were tested as moderators. Perceived stress and sleep problems mediated the association between noise sensitivity and subjective health complaints, while the moderators did not influence the overall model. Neuroticism, included in the models as a covariate, accounted for the association between noise sensitivity and mental health complaints. No association was found between noise sensitivity and self-reported hypertension.
Study 2 was conducted to assess the role of stress-related physiological changes that may be involved in the associations among noise sensitivity, perceived stress and health complaints in a community sample (n = 107; 51 males, 56 females aged 18-78 years). Specifically, using a subsection of the sample (n = 92), Study 2 tested the association between noise sensitivity and functioning of the hypothalamic-pituitary-adrenal (HPA) axis, a major stress system of the body, through assessment of the cortisol awakening response (CAR). The CAR captures general HPA axis functioning, which can be dysregulated under chronic stress, and may have detrimental effects on health and well-being. There was no significant relationship between noise sensitivity and CAR levels. However, gender emerged as the strongest predictor of overall cortisol output across the awakening period, with females exhibiting greater output than males. Females also reported greater perceived stress, noise sensitivity, and subjective health complaints than males.
Overall, this thesis significantly contributes to the understanding of the relationship between noise sensitivity and diminished health. Perceived stress and sleep problems mediated the association between noise sensitivity and subjective health complaints, while neuroticism accounted for the relationship between noise sensitivity and mental health complaints (anxiety and depression). HPA axis functioning was not related to noise sensitivity or health complaints. Results are discussed with reference to the importance of considering perceived stress and sleep problems in noise sensitivity research, and future directions for investigations on the association between noise sensitivity and diminished health.