Urban road traffic noise and annoyance: the effect of a quiet façade

Models of Aviation Noise Impact in the Context of Operation Decrease at Tan Son Nhat Airport

Air traffic bans in response to the spread of the coronavirus have changed the sound situation of urban areas around airports. This study aimed to investigate the effect of this unprecedented event on the community response to noise before and after the international flight operation at Tan Son Nhat Airport (TSN) in March 2020. The "before" survey was conducted in August 2019, and the two "after" surveys were conducted in June and September 2020. Structural equation models (SEMs) for noise annoyance and insomnia were developed by linking the questionnaire items of the social surveys. The first effort aimed to achieve a common model of noise annoyance and insomnia, corresponding to the situation before and after the change, respectively. Approximately, 1200 responses were obtained from surveys conducted in 12 residential areas around TSN in 2019 and 2020. The average daily flight numbers observed in August 2019 during the two surveys conducted in 2020 were 728, 413, and 299, respectively. The sound pressure levels of the 12 sites around TSN decreased from 45-81 dB (mean = 64, SD = 9.8) in 2019 to 41-76 dB (mean = 60, SD = 9.8) and 41-73 dB (mean = 59, SD = 9.3) in June and September 2020, respectively. The SEM indicated that the residents' health was related to increased annoyance and insomnia.

The actual and ideal indoor soundscape for work, relaxation, physical and sexual activity at home: A case study during the COVID-19 lockdown in London

The period of home confinement during the COVID-19 pandemic made the importance of a high-quality surrounding environment even more evident than before. Several studies have been carried out to assess the (negative) impacts of noise on annoyance, particularly whilst working from home (WFH). The present study takes a step further by (1) investigating the positive and negative impacts of the "actual" acoustic environment on a range of activities, i.e., WFH, relaxation, physical, and sexual activities, and (2) identifying the characteristics of an "ideal" indoor soundscape. The study is based on the qualitative analysis of verbal descriptions collected from open-ended questions included in a survey administered in January 2021 to 464 respondents living in London, during the COVID-19 lockdown. The range of impacts in the actual scenario varied from no effect on task execution, to disruption, distraction, concern of disturbing others or being heard. Positive impacts included support of concentration, relaxation, motivation, freedom of sound expression, feeling of being connected to the surroundings and comforted by the presence of others, according to mechanisms described in the study. Negative appraisal could trigger coping strategies (e.g., controlling windows, playing music, wearing headphones) and behavioural changes (e.g., lowering the volume of the voice or music, muting oneself during call, changing workout type) that could in turn limit or enhance the freedom of behaviour, affect or foster wellbeing. Negative impacts were most frequently reported on WFH (by 55% of the participants), followed by relaxation activities (40.6%), sexual activities (30.1%), and home workout (20.1%). The ideal soundscape was described as a quiet, well-sound insulated environment, which guarantees access to positive sounds (i.e., natural sounds, music, urban background), thus resulting in privacy, intimacy, and a place where to express themselves without noise-related constraints. The study complements literature findings on housing design directions in light of the COVID-19 pandemic, by providing further evidence on the impacts of poor sound insulation at home, the potential benefits of nature-based solutions for positive indoor soundscapes, and opportunities for an activity-based design of domestic environments, inclusive of a broader set of home uses and household compositions.

Indoor soundscapes at home during the COVID-19 lockdown in London - Part II: A structural equation model for comfort, content, and well-being

The present work constitutes the sequel to the analysis of data from an online survey administered to 464 home workers in London in January 2021 during the COVID-19 lockdown. Perceived affective quality of indoor soundscapes has been assessed in the survey through a previously developed model, as the combination of two perceptual dimensions, one related to comfort (a comfortable - annoying continuum) and the other to content (a full of content - empty continuum). Part I of the study reported on differences in comfort, content, and soundscape appropriateness based on the activity performed at home during the lockdown, i.e. working from home (WFH) and relaxation. Moreover, associations between soundscape dimensions and psychological well-being have been highlighted. Part II of the study deals with the exploration of the influences of several acoustical, building, urban and person-related factors on soundscape dimensions and well-being. A mixed-method approach has been adopted by combining multivariate regression of questionnaire scores with the qualitative analysis of spontaneous descriptions given by respondents. Results showed that several sound sources, urban features, housing characteristics, working modes and demographic factors can influence (positively and negatively) soundscape dimensions differently depending on the task at hand. Notably, the perceived dominance of neighbours' noises during relaxation, moderated by noise sensitivity, and the number of people at home were common factors negatively affecting both comfort and well-being, that partially explained the association between comfortable indoor soundscapes and better mental health. The discussion points out the importance of considering the different impacts that acoustical factors (e.g. sound typology), building (e.g., house size), urban (e.g., availability of a quiet side), situational (e.g., number of people at home), and person-related factors (e.g., noise sensitivity) can provide on building occupants depending on the specific activity people are engaged with at home and the opportunities to foster people's well-being through building, urban and acoustic design.

The impact of nocturnal road traffic noise, bedroom window orientation, and work-related stress on subjective sleep quality: results of a cross-sectional study among working women

Objective

To examine the effect of work-related stress and road noise exposure on self-rated sleep and potential additive interaction effects.

Methods

Sleep and predictor variables were surveyed within two subsamples with 2191 and 1764 working women in a cross-sectional study. Sleep was assessed using a single question on general sleep quality and four questions on specific sleep problems and subsequently dichotomized (poor sleep vs. no poor sleep). Work-related stress was operationalized by job strain and effort-reward imbalance. Nocturnal exposure to road traffic noise was assessed as (a) the orientation of the bedroom window to a quiet façade vs. a low-, medium- or high-trafficked street and (b) energy-equivalent sound pressure levels for night-time modelled at the most exposed façade (L_night). We distinguished between low (< 45 dB(A)), medium (45–50 dB(A)) and high exposure (> 50 dB(A)).

Results

Poor sleep was associated with job strain and effort-reward imbalance. The prevalence of poor sleep did not increase with increasing L_night, but bedroom window orientation showed a non-significant trend. A quiet façade had a protective effect on sleep in each L_night category. We found a non-significant trend for an additive interaction between bedroom window orientation and job strain.

Conclusion

Noise levels modelled for the most exposed façade likely overestimate the actual exposure and thus may not be a precise predictor of poor sleep. Bedroom window orientation seems more relevant. Potential additive interaction effects between bedroom window orientation and job strain should be considered when interpreting epidemiological study results on noise-induced sleep disturbances.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00420-021-01696-w.

Associations and effect modification between transportation noise, self-reported response to noise and the wider determinants of health: A narrative synthesis of the literature

Noise and health guidance to date have focused on the direct links between noise and health outcomes such as annoyance, sleep disturbance, cardiovascular and metabolic disease, and cognitive impairment in schoolchildren. However, noise is a psychosocial stressor, and there are individual studies showing that exposure to noise or the self-reported responses to noise may affect health through interactions with the wider determinants of health and well-being including physical activity, use of green spaces and social interactions. Despite this emerging evidence concerning potential impacts of noise on the wider determinants of health, literature in the field remains dispersed and unsynthesised. This study seeks to synthetize evidence on different relationships between transportation noise, self-reported responses to noise and the wider determinants of health using a systematic review methodology. The search was conducted in Medline, PsycINFO, PubMed, and Scopus on articles published from 2000 to 2017. This led to the review of 76 papers which satisfied the inclusion criteria. Despite strong heterogeneity in the studies' methodologies and indicators used, there is some evidence that noise exposure and responses to noise such as annoyance and disturbance are associated with people's lifestyle, recreational activities as well as the local economy of the neighbourhood. On the other hand, there are some wider determinants of health, mainly those related to the built and natural environment, which modify the relationship between noise exposure and self-reported responses to noise. In particular, greenness, having access to quiet areas, and covering noise sources either visually or acoustically with natural features seems to decrease people's negative responses to noise. Results indicate that transportation noise has the potential to affect health through various pathways, and a holistic approach is needed to capture all the effects.

Residential green is associated with reduced annoyance to road traffic and railway noise but increased annoyance to aircraft noise exposure

BACKGROUND

In recent years, residential green and availability of neighbourhood green spaces came into focus as a potential means to reduce transportation noise annoyance. Literature suggests that various characteristics of residential green may play a role, namely, greenness of the residential areas as quantified by the normalized difference vegetation index (NDVI), visible vegetation from home, and the presence of public green spaces as identified by land use classification data (LU-green), as well as their accessibility and noise pollution (i.e., transportation noise exposure within green areas, how loud/quiet they are). So far, studies mostly focused on road traffic noise in urban areas.

OBJECTIVE

We investigated the effects of residential green on noise annoyance, accounting for different transportation noise sources as well as for the degree of urbanisation.

METHODS

We complemented the data set of the recent Swiss SiRENE survey on road traffic, railway and aircraft noise annoyance with a wide range of "green" metrics, and investigated their association with annoyance by means of logistic regression analysis (generalized estimating equations).

RESULTS

Increasing residential green was found to be associated with reduced road traffic and railway noise annoyance, but increased aircraft noise annoyance. The overall effect corresponded to equivalent level reductions of about 6 dB for road traffic and 3 dB for railway noise, but to an increase of about 10 dB for aircraft noise, when residential green increased from "not much green" (5th percentile of the study sample distribution) to "a lot of green" (95th percentile). Overall, NDVI and LU-green were particularly strongly linked to annoyance. The effects of visible vegetation from home and accessibility and/or quietness of green spaces were, overall, less strong, but depended on the degree of urbanisation. For road traffic noise, visible vegetation and accessibility of green spaces seem to particularly strongly reduce annoyance in cities, while quiet green spaces are more effective in rural areas.

CONCLUSIONS

Our study emphasizes that residential green should be fostered by city planners, particularly in densely populated areas.

Urban Noise and Psychological Distress: A Systematic Review

Chronic exposure to urban noise is harmful for auditory perception, cardiovascular, gastrointestinal and nervous systems, while also causing psychological annoyance. Around 25% of the EU population experience a deterioration in the quality of life due to annoyance and about 5-15% suffer from sleep disorders, with many disability-adjusted life years (DALYs) lost annually. This systematic review highlights the main sources of urban noise, the relevant principal clinical disorders and the most effected countries. This review included articles published on the major databases (PubMed, Cochrane Library, Scopus), using a combination of some keywords. The online search yielded 265 references; after selection, the authors have analyzed 54 articles (5 reviews and 49 original articles). From the analysis, among the sources of exposure, we found the majority of items dealing with airports and wind turbines, followed by roads and trains; the main disorders that were investigated in different populations dealt with annoyance and sleep disorders, sometimes associated with cardiovascular symptoms. Regarding countries, studies were published from all over the world with a slight prevalence from Western Europe. Considering these fundamental health consequences, research needs to be extended in such a way as to include new sources of noise and new technologies, to ensure a health promotion system and to reduce the risk of residents being exposed.

Long-term residential road traffic noise and mortality in a Danish cohort

Transportation noise is a growing public health concern worldwide and epidemiological evidence has linked road traffic noise with mortality. However, incongruent effect estimates have been reported between incidence and mortality studies. Therefore, the present study aimed to investigate whether long-term exposure to residential road traffic noise at the most and least exposed façades was associated with all-cause, cardiovascular disease (CVD), ischemic heart disease (IHD), stroke, respiratory, or cancer mortality in a Danish cohort study. In a cohort of 52,758 individuals from Copenhagen and Aarhus, we estimated road traffic noise at the most and least exposed façades, as well as ambient air pollution, at all present and historical residential addresses from 1987 to 2016. Using the Danish cause of death register we identified cause-specific mortality. Analyses were conducted using Cox proportional hazards models. Ten-year time-weighted mean road traffic noise exposure at the most exposed façade was associated with an 8% higher risk for all-cause mortality per interquartile range (IQR; 10.4 dB) higher exposure level (95% CI: 1.05-1.11). Higher risks were also observed for CVD (HR = 1.13, 95% CI: 1.06-1.19) and stroke (HR = 1.11, 95% CI: 0.99-1.25) mortality. Road traffic noise at the least exposed façade (per IQR; 8.4 dB) was associated with CVD (HR = 1.09, 95% CI: 1.03-1.15), IHD (HR = 1.10, 95% CI: 1.01-1.21) and stroke (HR = 1.06, 95% CI: 0.95-1.19) mortality. Results were robust to adjustment for PM_2.5 and NO₂. In conclusion, this study adds to the body of evidence linking exposure to road traffic noise with higher risk of mortality.

Self-Reported Sleep Disturbance from Road, Rail and Aircraft Noise: Exposure-Response Relationships and Effect Modifiers in the SiRENE Study

This survey investigates the cross-sectional association between nighttime road, rail and aircraft noise exposure and the probability to be highly sleep disturbed (%HSD), as measured by self-report in postal and online questionnaires. As part of the Swiss SiRENE study, a total of 5592 survey participants in the entire country were selected based on a stratified random sample of their dwelling. Self-reported sleep disturbance was measured using an ICBEN-style 5-point verbal scale. The survey was carried out in four waves at different times of the year. Source-specific noise exposure was calculated for several façade points for each dwelling. After adjustment for potential confounders, all three noise sources showed a statistically significant association between the nighttime noise level LNight at the most exposed façade point and the probability to report high sleep disturbance, as determined by logistic regression. The association was strongest for aircraft noise and weakest for road traffic noise. We a priori studied the role of a range of effect modifiers, including the “eventfulness” of noise exposure, expressed as the Intermittency Ratio (IR) metric, bedroom window position, bedroom orientation towards the closest street, access to a quiet side of the dwelling, degree of urbanization, sleep timing factors (bedtime and sleep duration), sleep medication intake, survey season and night air temperature. While bedroom orientation exhibited a strong moderating effect, with an Leq-equivalent of nearly 20 dB if the bedroom faces away from the nearest street, the LNight-%HSD associations were not affected by bedroom window position, sleep timing factors, survey season, or temperature.

A survey on exposure-response relationships for road, rail, and aircraft noise annoyance: Differences between continuous and intermittent noise

The aim of the present study is to establish exposure-response relationships reflecting the percentage highly annoyed (%HA) as functions of road traffic, railway, and aircraft noise exposure, measured as day-evening-night level (Lden), as well as to elucidate the degree to which the acoustic indicator Intermittency Ratio (IR), which reflects the "eventfulness" of a noise situation, predicts noise annoyance. We conducted a mixed-mode representative population survey in a stratified random sample of 5592 residents exposed to transportation noise all over Switzerland. Source-specific noise exposure was calculated for each floor and each façade based on comprehensive traffic data. Noise annoyance was measured using the ICBEN 11-point scale. The survey was carried out in 4 waves at different times of the year. We hypothesized that in addition to Lden, the effects of noise on annoyance can be better explained when also considering the intensity of short-term variations of noise level over time. We therefore incorporated the acoustic indicator IR in the statistical models. For all noise sources, results revealed significant associations between Lden and %HA after controlling for confounders and independent predictors such as IR (measured over 24 h), exposure to other transportation noise sources, sex and age, language, home ownership, education level, living duration, temperature, and access to a quiet side of the dwelling. Aircraft noise annoyance scored markedly higher than annoyance to railway and road traffic noise at the same Lden level. Railway noise elicited higher percentages of highly annoyed persons than road traffic noise. Results furthermore suggest that for road traffic noise, IR has an additional effect on %HA and can explain shifts of the exposure-response curve of up to about 6 dB between low IR and high IR exposure situations, possibly due to the effect of different durations of noise-free intervals between events. For railway and aircraft noise annoyance, the predictive value of IR was limited.

Home as a Place of Noise Control for the Elderly? A Cross-Sectional Study on Potential Mediating Effects and Associations between Road Traffic Noise Exposure, Access to a Quiet Side, Dwelling-Related Green and Noise Annoyance

Urban residents&rsquo; need to be in control of their home environment can be constrained by perceived uncontrollability of exposure to road traffic noise. Noise annoyance may indicate a psychological stress reaction due to this uncontrollability perception, thereby undermining the restoration process. Environmental resources, such as having access to a quiet side at home and dwelling-related green, may reduce noise annoyance both directly by shielding acoustically and indirectly by enhancing residents&rsquo; perceived noise control. We assessed the potential mediating role of perceived noise control in independent and joint associations of road traffic noise exposure (>65 dB L_den) and of an absent dwelling-related environmental resource (three indicators concerning quiet sides and one indicator concerning dwelling-related green) with noise annoyance. In our cross-sectional, questionnaire-based study on elderly urban citizens (N = 1812), we observed a statistically significant indirect effect of noise exposure on noise annoyance through perceived noise control (39%, 95%CI 26⁻55%). Statistical mediation between indicators of absent environmental resources and noise annoyance was weaker. The potential indirect effect was confirmed for combinations of noise exposure with each of the four indicators of an absent environmental resource. Our findings may call for mitigating noise levels while fostering quietness and green at residents&rsquo; homes.

WHO Environmental Noise Guidelines for the European Region: A Systematic Review of Transport Noise Interventions and Their Impacts on Health

This paper describes a systematic review (1980-2014) of evidence on effects of transport noise interventions on human health. The sources are road traffic, railways, and air traffic. Health outcomes include sleep disturbance, annoyance, cognitive impairment of children and cardiovascular diseases. A conceptual framework to classify noise interventions and health effects was developed. Evidence was thinly spread across source types, outcomes, and intervention types. Further, diverse intervention study designs, methods of analyses, exposure levels, and changes in exposure do not allow a meta-analysis of the association between changes in noise level and health outcomes, and risk of bias in most studies was high. However, 43 individual transport noise intervention studies were examined (33 road traffic; 7 air traffic; 3 rail) as to whether the intervention was associated with a change in health outcome. Results showed that many of the interventions were associated with changes in health outcomes irrespective of the source type, the outcome or intervention type (source, path or infrastructure). For road traffic sources and the annoyance outcome, the expected effect-size can be estimated from an appropriate exposure-response function, though the change in annoyance in most studies was larger than could be expected based on noise level change.

Cognitive-Motivational Determinants of Residents' Civic Engagement and Health (Inequities) in the Context of Noise Action Planning: A Conceptual Model

The Environmental Noise Directive expects residents to be actively involved in localising and selecting noise abatement interventions during the noise action planning process. Its intervention impact is meant to be homogeneous across population groups. Against the background of social heterogeneity and environmental disparities, however, the impact of noise action planning on exposure to traffic-related noise and its health effects is unlikely to follow homogenous distributions. Until now, there has been no study evaluating the impact of noise action measures on the social distribution of traffic-related noise exposure and health outcomes. We develop a conceptual (logic) model on cognitive-motivational determinants of residents’ civic engagement and health (inequities) by integrating arguments from the Model on household’s Vulnerability to the local Environment, the learned helplessness model in environmental psychology, the Cognitive Activation Theory of Stress, and the reserve capacity model. Specifically, we derive four hypothetical patterns of cognitive-motivational determinants yielding different levels of sustained physiological activation and expectancies of civic engagement. These patterns may help us understand why health inequities arise in the context of noise action planning and learn how to transform noise action planning into an instrument conducive to health equity. While building on existing frameworks, our conceptual model will be tested empirically in the next stage of our research process.

ICBEN review of research on the biological effects of noise 2011-2014

The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences are needed to promote public health.

Annoyance, sleep and concentration problems due to combined traffic noise and the benefit of quiet side

Background: Access to a quiet side in one’s dwelling is thought to compensate for higher noise levels at the most exposed façade. It has also been indicated that noise from combined traffic sources causes more noise annoyance than equal average levels from either road traffic or railway noise separately. Methods: 2612 persons in Malmö, Sweden, answered to a residential environment survey including questions on outdoor environment, noise sensitivity, noise annoyance, sleep quality and concentration problems. Road traffic and railway noise was modeled using Geographic Information System. Results: Access to a quiet side, i.e., at least one window facing yard, water or green space, was associated with reduced risk of annoyance OR (95%CI) 0.47 (0.38–0.59), and concentration problems 0.76 (0.61–0.95). Bedroom window facing the same environment was associated to reduced risk of reporting of poor sleep quality 0.78 (0.64–1.00). Railway noise was associated with reduced risk of annoyance below 55 dB(A) but not at higher levels of exposure. Conclusions: Having a window facing a yard, water or green space was associated to a substantially reduced risk of noise annoyance and concentration problems. If this window was the bedroom window, sleeping problems were less likely.

Modeling environmental noise exceedances using non-homogeneous Poisson processes

In this work a non-homogeneous Poisson model is considered to study noise exposure. The Poisson process, counting the number of times that a sound level surpasses a threshold, is used to estimate the probability that a population is exposed to high levels of noise a certain number of times in a given time interval. The rate function of the Poisson process is assumed to be of a Weibull type. The presented model is applied to community noise data from Messina, Sicily (Italy). Four sets of data are used to estimate the parameters involved in the model. After the estimation and tuning are made, a way of estimating the probability that an environmental noise threshold is exceeded a certain number of times in a given time interval is presented. This estimation can be very useful in the study of noise exposure of a population and also to predict, given the current behavior of the data, the probability of occurrence of high levels of noise in the near future. One of the most important features of the model is that it implicitly takes into account different noise sources, which need to be treated separately when using usual models.

Road traffic noise, sleep and mental health

This study examines the relationship between road traffic noise, self-reported sleep quality and mental health. The study is cross-sectional and based on data from a survey conducted in Oslo, Norway, in 2000. Psychological distress (Hopkins Symptom Checklist, HSCL-25) was measured along with self-reported somatic health, sleep quality, noise sensitivity and socioeconomic variables. Questionnaire data were combined with modeled estimates of noise exposure. The total study sample consisted of 2898 respondents. After adjustment for potential confounders and stratifying for sleep quality, we found a positive, but not statistically significant association between noise exposure and symptoms of psychological distress among participants with poor sleep quality (slope=0.06, 95% CI: -0.02 to 0.13, per 10 dB increase in noise exposure). In the same sleep quality group, we found a borderline statistically significant association between noise exposure and a symptom level indicating a probable mental disorder (HSCL≥1.55) (odds ratio=1.47, 95% CI: 0.99-1.98, per 10 dB increase in noise exposure). We found no association between road traffic noise and mental health among subjects reporting good and medium sleep quality. The results suggest that road traffic noise may be associated with poorer mental health among subjects with poor sleep. Individuals with poor sleep quality may be more vulnerable to effects of road traffic noise on mental health than individuals with better sleep quality.

Application of a methodology for categorizing and differentiating urban soundscapes using acoustical descriptors and semantic-differential attributes

A subjective and physical categorization of an ambient sound is the first step to evaluate the soundscape and provides a basis for designing or adapting this ambient sound to match people's expectations. For this reason, the main goal of this work is to develop a categorization and differentiation analysis of soundscapes on the basis of acoustical and perceptual variables. A hierarchical cluster analysis, using 15 semantic-differential attributes and acoustical descriptors to include an equivalent sound-pressure level, maximum-minimum sound-pressure level, impulsiveness of the sound-pressure level, sound-pressure level time course, and spectral composition, was conducted to classify soundscapes into different typologies. This analysis identified 15 different soundscape typologies. Furthermore, based on a discriminant analysis the acoustical descriptors, the crest factor (impulsiveness of the sound-pressure level), and the sound level at 125 Hz were found to be the acoustical variables with the highest impact in the differentiation of the recognized types of soundscapes. Finally, to determine how the different soundscape typologies differed from each other, both subjectively and acoustically, a study was performed.

Road traffic noise and annoyance: a quantification of the effect of quiet side exposure at dwellings

Previous studies indicate that residents may benefit from a “quiet side” to their dwellings. The influence of the level of road traffic noise exposure at the least exposed side on road traffic noise annoyance was studied in Amsterdam, The Netherlands. Road traffic noise exposure was assessed at the most and least exposed façade (L_den,most and L_den,least respectively) of dwellings for subjects in a population based survey (N = 1,967). It was investigated if and to what extent relative quietness at the least exposed façade affected the level of road traffic noise annoyance by comparing two groups: (1) The subgroup with a relatively quiet façade; (2) the subgroup without a relatively quiet façade (large versus small difference in exposure between most and least exposed façade; DIF ≥ 10 dB and DIF < 10 dB respectively). In addition, it was investigated if and to what extent L_den,least affected the level of road traffic noise annoyance. Results indicate a significantly lower road traffic noise annoyance score at a given L_den,most, in the subgroup with DIF ≥ 10 dB versus DIF < 10 dB. Furthermore, results suggest an effect of L_den,least independent of L_den,most. The estimated size of the effect expressed in an equivalent change in L_den,most approximated 5 dB for both the difference between the two subgroups (DIF ≥ 10 dB and DIF < 10 dB), and for a 10 dB change in L_den,least.

Focused study on the quiet side effect in dwellings highly exposed to road traffic noise

This study provides additional evidence for the positive effect of the presence of a quiet façade at a dwelling and aims at unraveling potential mechanisms. Locations with dominant road traffic noise and high L_den-levels at the most exposed façade were selected. Dwellings both with and without a quiet façade were deliberately sought out. Face-to-face questionnaires (N = 100) were taken to study the influence of the presence of a quiet side in relation to noise annoyance and sleep disturbance. As a direct effect, the absence of a quiet façade in the dwelling (approached as a front-back façade noise level difference smaller than 10 dBA) leads to an important increase of at least moderately annoyed people (odds-ratio adjusted for noise sensitivity equals 3.3). In an indirect way, a bedroom located at the quiet side leads to an even stronger reduction of the self-reported noise annoyance (odds-ratio equal to 10.6 when adjusted for noise sensitivity and front façade L_den). The quiet side effect seems to be especially applicable for noise sensitive persons. A bedroom located at the quiet side also reduces noise-induced sleep disturbances. On a loud side, bedroom windows are more often closed, however, conflicting with the preference of dwellers.

How pleasant sounds promote and annoying sounds impede health: a cognitive approach

This theoretical paper addresses the cognitive functions via which quiet and in general pleasurable sounds promote and annoying sounds impede health. The article comprises a literature analysis and an interpretation of how the bidirectional influence of appraising the environment and the feelings of the perceiver can be understood in terms of core affect and motivation. This conceptual basis allows the formulation of a detailed cognitive model describing how sonic content, related to indicators of safety and danger, either allows full freedom over mind-states or forces the activation of a vigilance function with associated arousal. The model leads to a number of detailed predictions that can be used to provide existing soundscape approaches with a solid cognitive science foundation that may lead to novel approaches to soundscape design. These will take into account that louder sounds typically contribute to distal situational awareness while subtle environmental sounds provide proximal situational awareness. The role of safety indicators, mediated by proximal situational awareness and subtle sounds, should become more important in future soundscape research.

Exposure modifiers of the relationships of transportation noise with high blood pressure and noise annoyance

In the cross-sectional hypertension and exposure to noise near airports study the relationship between road traffic noise, aircraft noise and hypertension and annoyance was investigated. The data collection comprised a variety of potentially exposure modifying factors, including type of housing, location of rooms, window opening habits, use of noise-reducing remedies, shielding due to obstacles, lengths of exposure. In the present paper the quantitative role of these factors on the relationship between road and aircraft noise exposure and outcomes was analyzed. Multiple logistic and linear regression models were calculated including these co-factors and related interaction terms with noise indicators, as well as stratified analyses. Type of housing, length of residence, location of rooms and the use of noise reducing remedies modified the relationship between noise and hypertension. However, the effects were not always in the direction of a stronger association in higher exposed subjects. Regarding annoyance, type of housing, location of rooms, noise barriers, window opening habits, noise insulation, the use of noise reducing remedies, hours spent at home during daytime were significant effect modifiers. The use of noise-reducing remedies turned out to be indicators of perceived noise disturbance rather than modifiers reducing the annoyance.

Valuation of green walls and green roofs as soundscape measures: including monetised amenity values together with noise-attenuation values in a cost-benefit analysis of a green wall affecting courtyards

Economic unit values of soundscape/acoustic effects have been based on changes in the number of annoyed persons or on decibel changes. The normal procedure has been the application of these unit values to noise-attenuation measures affecting the noisier façade of a dwelling. Novel modular vegetation-based soundscape measures, so-called green walls, might be relevant for both noisy and quieter areas. Moreover, their benefits will comprise noise attenuation as well as non-acoustic amenity effects. One challenge is to integrate the results of some decades of non-acoustic research on the amenity value of urban greenery into design of the urban sound environment, and incorporate these non-acoustic properties in the overall economic assessment of noise control and overall sound environment improvement measures. Monetised unit values for green walls have been included in two alternative cases, or demonstration projects, of covering the entrances to blocks of flats with a green wall. Since these measures improve the noise environment on the quiet side of the dwellings and courtyards, not the most exposed façade, adjustment factors to the nominal quiet side decibel reductions to arrive at an estimate of the equivalent overall acoustic improvement have been applied. A cost-benefit analysis of the green wall case indicates that this measure is economically promising, when valuing the noise attenuation in the quieter area and adding the amenity/aesthetic value of the green wall.