| Abstrakt: |
Direct reanalyses of over 57 000 interview responses to 35 noise sources in 20 social surveys and reviews of publications for over 12 000 additional responses to 16 noise sources in 13 social surveys show that residents' reactions to an audible environmental noise (a target noise) are only slightly or not at all reduced by the presence of another noise source (ambient noise) in residential environments. The direct reanalyses account for type of noise source (aircraft, road traffic, railway, impulse noise), type of noise reaction question, type of activity disturbance, quality of noise data, type of regression analysis model (linear, logit, probit), two noise metrics (DNL, LAeq), and ten personal characteristics. Although there is considerable variation from survey to survey, the best direct estimate is that approximately a 20-dB increase in ambient noise exposure (95% confidence interval of 15-50 dB) has no more impact than approximately a 1-dB decrease in target noise exposure. Tabulations of 12 findings from laboratory studies in which subjects rated periods of multiple noise events also found that target noise annoyance is not consistently reduced by ambient noise. © 1998 Acoustical Society of America. [ABSTRACT FROM AUTHOR] |
