Response to a change in transport noise exposure: competing explanations of change effects

Lowering urban speed limits to 30 km/h reduces noise annoyance and shifts exposure-response relationships: Evidence from a field study in Zurich

BACKGROUND

The city of Zurich progressively pursuits a strategy of reducing road traffic noise by lowering the speed limit to 30 km/h on street sections that exceed the legal noise limits. Aim of this study was to evaluate the effects of the reduced speed limit on noise levels (Lday and Lnight), noise annoyance, self-reported sleep disturbance, perceived road safety, and in particular, to elucidate if the reduced speed limit leads to a shift of exposure-response relationships towards lower effects.

METHODS

We surveyed about 1300 randomly sampled inhabitants, in a repeated measures study, before and after the speed rule changeover from 50 km/h to 30 km/h along 15 city street sections, by postal questionnaire. Concurrently, individual noise exposure calculations based on traffic counts and on-site speed measurements were carried out before and after the changeover.

RESULTS

Road traffic noise Leq's at the loudest façade point dropped by an average of 1.6 dB during day and 1.7 dB at night. A statistically significant decrease of noise annoyance and of self-reported sleep disturbances was observed, as well as a moderate but significant increase of perceived road safety. Most importantly, the exposure-response relationships for annoyance and sleep disturbance were shifted towards lower effects in the 30 km/h condition by, depending on receiver point, between about 2 dB and 4 dB during the day and about 4 dB at night, indicating lower effects at the same average level. This is a hint that, in addition to lower average exposure levels alone, other factors related to the lower driving speed additionally reduce noise annoyance and sleep disturbance.

CONCLUSIONS

City dwellers probably benefit from traffic speed reductions to a greater degree than would be expected from the reduction in average level attained by the lower driving speed alone.

Effects of Noise and Vibration Due to the Hokuriku Shinkansen Railway on the Living Environment: A Socio-Acoustic Survey One Year after the Opening

One year after the opening of the Hokuriku Shinkansen (high-speed) railway, in 2016, we conducted a social survey targeting the residents of detached houses along the rail. Noise and vibration exposure levels were estimated at outdoor points closest to the noise source side of the houses. Of the 1980 people contacted, there were 1022 valid respondents. The purpose of this research was to investigate the relationship between noise and vibration exposure and community responses. The results demonstrated that the noise annoyance and daily activity disturbances of residents living in areas without a conventional railway are higher than those of residents living in areas running parallel to a conventional railway line. This tendency was remarkable, especially for areas with high vibration exposure caused by the Shinkansen railway. There was no difference between before and after the opening of the Shinkansen railway in the evaluation of housing satisfaction, or regarding the preference for the residential area and quietness around the house. However, since the survey before the opening was conducted only in the Ishikawa site, it will be necessary to conduct before-and-after surveys in areas where there are no conventional railways, and where the speed of the Shinkansen is fast.

Effects of Changes in Acoustic and Non-Acoustic Factors on Public Health and Reactions: Follow-Up Surveys in the Vicinity of the Hanoi Noi Bai International Airport

Herein, the effects of changes in acoustic and non-acoustic factors on public health and reactions were assessed using two follow-up investigations; this was achieved after three surveys were conducted on the impact of the step change in noise caused by the increased number of flights at the Noi Bai International Airport in Hanoi (Vietnam) after the new terminal building was opened to the public. Exposure-response relationships established in the follow-up studies were less in number than those established in 2015 after the step change had occurred, and were almost similar to the relationship established in the survey conducted before the step change; however, these relationships were significantly greater than those established in the European Union position paper. Comparisons between respondents with high blood pressure and insomnia ratios at different noise level ranges showed that there is no significant association between ratios of high blood pressure and day-evening-night noise levels; however, an exposure-response relationship was discovered between insomnia and night-time noise levels. Non-acoustic factors such as noise sensitivity, sound insulation capacity of houses, and length of residence were found to curb the respondents’ annoyance, insomnia, and high blood pressure. Thus, an improvement in residence quality and a restriction on nighttime flight operation is necessitated.

Using mindfulness to reduce the health effects of community reaction to aircraft noise

Aim:

This paper investigates whether mindfulness-based interventions might ameliorate the detrimental health effects of aircraft noise on residential communities.

Review:

Numerous empirical studies over the past 50 years have demonstrated the increasing negative impact of aircraft noise on residents worldwide. However, extensive database searches have revealed no published studies on psychological interventions that reduce residents’ reactivity to environmental noise. By contrast, there has been extensive research over several decades confirming the effectiveness of mindfulness-based stress reduction training in lowering people’s stress from work and life. Considering that stress is a major component of aircraft noise reaction, it would seem worth assessing whether mindfulness-based interventions might be effective in reducing the health effects of aircraft noise. It appears that no existing conceptualization of mindfulness specifically accounts for noise as a stressor.

Conceptual Analysis:

A new conceptual model is presented here which explains how mindfulness can reduce noise reactivity. Two types of mindfulness are distinguished: an active form (meta-mindfulness) and a passive form (supra-mindfulness). It is posited that meta-mindfulness can facilitate “cognitive defusion” which research has confirmed as enabling people to disconnect from their own dysfunctional thoughts. In the case of aircraft noise, negative thinking associated with residents’ reactive experiences can exacerbate the health effects they suffer. The present model further proposes that supra-mindfulness can enable an individual to disengage their own sense of identity from the often overwhelming negative thoughts which can define their existence when they are consumed by extreme noise annoyance.

Conclusion:

The mindfulness processes of defusion and disidentification are postulated to be the key efficacy mechanisms potentially responsible for reducing reactivity to aircraft noise. This approach can be evaluated by extending previous research on the health benefits of mindfulness training.

Effects of Railway Elevation, Operation of a New Station, and Earthquakes on Railway Noise Annoyance in Kumamoto, Japan

This study investigated the effects of railway elevation, operation of a new station, and earthquakes on railway noise annoyance in two areas along a conventional railway line (CRL) adjacent to the Kyushu Shinkansen line: the north area with the CRL elevation and the south area with the operation of the new station, both of which occurred in March 2016. In April 2016, Kumamoto region was struck by a series of large earthquakes, prompting their inclusion in this study, as frequent aftershocks with loud ground rumbling might make people more sensitive to railway noise and vibration. Socioacoustic surveys were performed in both areas before and after the earthquakes. Because very few respondents in the north area reported that they were “highly annoyed,” further analysis was conducted on data from the south area. The exposure–annoyance relationship was found to be significantly higher in 2017 than in 2011 despite lower noise exposure. Multiple logistic regression analysis showed that L_den, noise sensitivity, and serious damage by the earthquakes in addition to the operation of the new station significantly affected the annoyance in both detached and apartment houses. However, when the earthquakes caused minimal damage, they did not significantly affect annoyance.

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’ 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’ 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’ homes.

The Development of a Multiple-Item Annoyance Scale (MIAS) for Transportation Noise Annoyance

In 2001, Team#6 of the International Commission on Biological Effects of Noise (ICBEN) recommended the use of two single international standardised questions and response scales. This recommendation has been widely accepted in the scientific community. Nevertheless, annoyance can be regarded as a multidimensional construct comprising the three elements: (1) experience of an often repeated noise-related disturbance and the behavioural response to cope with it, (2) an emotional/attitudinal response to the sound and its disturbing impact, and (3) the perceived control or coping capacity with regard to the noise situation. The psychometric properties of items reflecting these three elements have been explored for aircraft noise annoyance. Analyses were conducted using data of the NORAH-Study (Noise-Related Annoyance, Cognition, and Health), and a multi-item noise annoyance scale (MIAS) has been developed and tested post hoc by using a stepwise process (exploratory and confirmatory factor analyses). Preliminary results were presented to the 12th ICBEN Congress in 2017. In this study, the validation of MIAS is done for aircraft noise and extended to railway and road traffic noise. The results largely confirm the concept of MIAS as a second-order construct of annoyance for all of the investigated transportation noise sources; however, improvements can be made, in particular with regard to items addressing the perceived coping capacity.

Community response to a step change in the aircraft noise exposure around Hanoi Noi Bai International Airport

In December 2014, a new terminal building was opened at the Hanoi Noi Bai International Airport (HNBIA) with two runways, causing a 20%-30% increase in the number of flights. Three socio-acoustic surveys were conducted in August-September 2014, February-March 2015, and August-September 2015, to contribute not only to the environmental impact assessments and aircraft noise policies in Vietnam but also to more global intervention studies. Because of the change of runway use, in addition to the increased number of flights, noise exposure at each site changed considerably among the surveys. Changes in the noise exposure from the first to the second or third survey (ΔL_den and ΔL_night) were used as a measure of exposure change. Multiple logistic regression analysis showed that ΔL_den has a significant positive effect on annoyance regardless of ΔL_den ranges, but the effect of ΔL_night on insomnia was significant only for ΔL_night > 0. Annoyance increase in the overall ΔL_den range may be caused by the respondents' recognition of increase in emission in addition to practical increase in exposure. More severe attitudes to airplanes around HNBIA might increase annoyance even if noise exposure decreases. Thus, the change effect clearly occurs in annoyance but partially in insomnia.

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.

Short-term annoyance from nocturnal aircraft noise exposure: results of the NORAH and STRAIN sleep studies

PURPOSE

The German Aerospace Center (DLR) investigated in the NORAH sleep study the association between a distinct change in nocturnal aircraft noise exposure due to the introduction of a night curfew (11:00 p.m.-5:00 a.m.) at Frankfurt Airport and short-term annoyance reactions of residents in the surrounding community. Exposure-response curves were calculated by random effects logistic regression to evaluate the aircraft noise-related parameters (1) number of overflights and (2) energy equivalent noise level L_ASeq for the prediction of short-term annoyance. Data of the NORAH sleep study were compared with the STRAIN sleep study which was conducted by DLR near Cologne-Bonn Airport in 2001/2002 (N = 64), representing a steady-state/low-rate change.

METHODS

The NORAH sleep study was based on questionnaire surveys with 187 residents living in the vicinity of Frankfurt Airport. Noise-induced short-term annoyance and related non-acoustical variables were assessed. Nocturnal aircraft noise exposure was measured inside the residents' home.

RESULTS

A statistically significant rise in the portion of annoyed residents with increasing number of overflights was found. Similarly, the portion of annoyed subjects increased with rising L_ASeq. Importance of the frequency of fly-overs for the prediction of annoyance reactions was emphasized. The annoyance probability was significantly higher in the NORAH than in the STRAIN sleep study.

CONCLUSIONS

Results confirm the importance of both acoustical parameters for the prediction of short-term annoyance due to nocturnal aircraft noise. Quantitative annoyance models that were derived at steady-state/low-rate change airports cannot be directly applied to airports that underwent a distinct change in operational and noise exposure patterns.

Do perceived job insecurity and annoyance due to air and noise pollution predict incident self-rated poor health? A prospective analysis of independent and joint associations using a German national representative cohort study

BACKGROUND

Current economic and social change has contributed to increasing job insecurity and traffic-related pollution in residential areas. Both job insecurity and exposure to noise and air pollution are known determinants of population health and can concur in peoples' lives. This may hold true particularly for socially disadvantaged subpopulations. Nevertheless, the potential independent and joint links of those exposures to health have been rarely examined so far. We aimed to contribute to the scarce body of evidence.

METHODS

Information on perceived job insecurity and exposures to noise and air pollution as expressed by annoyance as well as on self-rated health were gathered from 2 waves of the population-based German Socio-Economic Panel (2009 and 2011, N=6544). We performed multivariable Poisson regression to examine the independent and joint risk of poor health in 2011 by perceived job insecurity and annoyance due to noise and air pollution in 2009.

RESULTS

After the 2-year follow-up in 2011, 571 (8.7%) participants rated their health as poor. The risk of reporting incident poor health was increased by roughly 40% in employees reporting high versus low perceived job insecurity and annoyance due to noise and air pollution, respectively. This risk increased when both exposures were present at higher levels (risk ratio=1.95 (1.49 to 2.55)).

CONCLUSIONS

Work-related and environmental exposures may accumulate and have a joint health impact. Elaboration on the link between occupational and residential exposures is warranted in the light of their concurrence and their implications for health inequities.

Effect of Attitudinal, Situational and Demographic Factors on Annoyance Due to Environmental Vibration and Noise from Construction of a Light Rapid Transit System

The aim of this paper is to determine what non-exposure factors influence the relationship between vibration and noise exposure from the construction of a Light Rapid Transit (LRT) system and the annoyance of nearby residents. Noise and vibration from construction sites are known to annoy residents, with annoyance increasing as a function of the magnitude of the vibration and noise. There is not a strong correlation between exposure and levels of annoyance suggesting that factors not directly related to the exposure may have an influence. A range of attitudinal, situational and demographic factors are investigated with the aim of understanding the wide variation in annoyance for a given vibration exposure. A face-to-face survey of residents (n = 350) near three sites of LRT construction was conducted, and responses were compared to semi-empirical estimates of the internal vibration within the buildings. It was found that annoyance responses due to vibration were strongly influenced by two attitudinal variables, concern about property damage and sensitivity to vibration. Age, ownership of the property and the visibility of the construction site were also important factors. Gender, time at home and expectation of future levels of vibration had much less influence. Due to the measurement methods used, it was not possible to separate out the effects of noise and vibration on annoyance; as such, this paper focusses on annoyance due to vibration exposure. This work concludes that for the most cost-effective reduction of the impact of construction vibration and noise on the annoyance felt by a community, policies should consider attitudinal factors.

Windmill Noise Annoyance, Visual Aesthetics, and Attitudes towards Renewable Energy Sources

A small focused socio-acoustic after-study of annoyance from a windmill park was undertaken after local health officials demanded a health impact study to look into neighborhood complaints. The windmill park consists of 31 turbines and is located in the South of Norway where it affects 179 dwellings. Simple exposure-effect relationships indicate stronger reactions to windmills and wind turbine noise than shown internationally, with the caveat that the sample size is small (n = 90) and responses are colored by the existing local conflict. Pulsating swishing sounds and turbine engine hum are the main causes of noise annoyance. About 60 per cent of those who participated in the survey were of the opinion that windmills degrade the landscape aesthetically, and were far from convinced that land-based windmills are desirable as a renewable energy source (hydropower is an important alternative source of renewables in Norway). Attitudes play an important role in addition to visual aesthetics in determining the acceptance of windmills and the resulting noise annoyance. To compare results from different wind turbine noise studies it seems necessary to assess the impact of important modifying factors.

Does exposure to aircraft noise increase the mortality from cardiovascular disease in the population living in the vicinity of airports? Results of an ecological study in France

The impact of aircraft noise on health is of growing concern. We investigated the relationship between this exposure and mortality from cardiovascular disease, coronary heart disease, myocardial infarction, and stroke. We performed an ecological study on 161 communes (commune being the smallest administrative unit in France) close to the following three major French airports: Paris-Charles de Gaulle, Lyon Saint-Exupéry, and Toulouse-Blagnac. The mortality data were provided by the French Center on Medical Causes of Death for the period 2007-2010. Based on the data provided by the French Civil Aviation Authority, a weighted average exposure to aircraft noise (L_den AEI) was computed at the commune level. A Poisson regression model with commune-specific random intercepts, adjusted for potential confounding factors including air pollution, was used to investigate the association between mortality rates and L_den AEI. Positive associations were observed between L_den AEI and mortality from cardiovascular disease [adjusted mortality rate ratio (MRR) per 10 dB(A) increase in L_den AEI = 1.18; 95% confidence interval (CI): 1.11-1.25], coronary heart disease [MRR = 1.24 (1.12-1.36)], and myocardial infarction [MRR = 1.28 (1.11-1.46]. Stroke mortality was more weakly associated with L_den AEI [MRR = 1.08 (0.97-1.21]. These significant associations were not attenuated after the adjustment for air pollution. The present ecological study supports the hypothesis of an association between aircraft noise exposure and mortality from cardiovascular disease, coronary heart disease, and myocardial infarction. However, the potential for ecological bias and the possibility that this association could be due to residual confounding cannot be excluded.

Longitudinal annoyance responses to a road traffic noise management strategy that reduced heavy vehicles at night

A traffic management strategy was designed to reduce trucks using an urban corridor. The intervention had potential to affect night-time truck flows, but did not target truck traffic in the day, or vehicles other than trucks at any hour. A two-year long panel study measured the community's response to this intervention, using five repeated measurements of response. There were significant reductions in the panel's response to noise, both for night-time annoyance and for interference with activities. This was remarkable given that noise monitoring showed that the intervention produced no change in conventional traffic noise indicators. However, there were measureable changes in the number of articulated truck movements at night, and the benefit can be attributed to reduction in the number of noise events from heavy vehicles. The parallel tracking of changes in reported noise effects and the numbers of heavy vehicles in the night hours in this longitudinal study provides strong support to the notion that noise effects at night depend on the number of noise events experienced, not only on the overall level of traffic noise. The latter appear to be unresponsive indicators by which to assess the noise-effect benefit of heavy vehicle reduction strategies.

Perceptual constancy in auditory perception of distance to railway tracks

Distance to a sound source can be accurately estimated solely from auditory information. With a sound source such as a train that is passing by at a relatively large distance, the most important auditory information for the listener for estimating its distance consists of the intensity of the sound, spectral changes in the sound caused by air absorption, and the motion-induced rate of change of intensity. However, these cues are relative because prior information/experience of the sound source-its source power, its spectrum and the typical speed at which it moves-is required for such distance estimates. This paper describes two listening experiments that allow investigation of further prior contextual information taken into account by listeners-viz., whether they are indoors or outdoors. Asked to estimate the distance to the track of a railway, it is shown that listeners assessing sounds heard inside the dwelling based their distance estimates on the expected train passby sound level outdoors rather than on the passby sound level actually experienced indoors. This form of perceptual constancy may have consequences for the assessment of annoyance caused by railway noise.

Long-term effects of noise reduction measures on noise annoyance and sleep disturbance: the Norwegian facade insulation study

The Norwegian facade insulation study includes one pre-intervention and two post-intervention surveys. The facade-insulating measures reduced indoor noise levels by 7 dB on average. Before the intervention, 43% of the respondents were highly annoyed by noise. Half a year after the intervention, the proportion of respondents who were highly annoyed by road traffic noise had been significantly reduced to 15%. The second post-intervention study (2 yr after the first post-intervention study) showed that the proportion of highly annoyed respondents had not changed since the first post-intervention study. The reduction in the respondents' self-reported sleep disturbances (due to traffic noise) also remained relatively stable from the first to the second post-intervention study. In the control group, there were no statistically significant differences in annoyance between the pre-intervention and the two post-intervention studies. Previous studies of traffic changes have reported that people "overreact" to noise changes. This study indicated that when considering a receiver measure, such as facade insulation, the effect of reducing indoor noise levels could be predicted from exposure-response curves based on previous studies. Thus no evidence of an "overreaction" was found.

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.

Annoyance and other reaction measures to changes in noise exposure - a review

INTRODUCTION

Noise is increasingly recognised as a potentially important environmental pollutant but most studies on human responses to noise exposure relate to steady state situations. Effects may differ when noise changes rapidly, e.g. after noise mitigation interventions or with changes in road or airport configurations.

METHODS

A systematic review of studies on human reactions to changes in environmental noise exposures published from 1980 to March 2011 was conducted.

RESULTS

41 papers satisfied the inclusion criteria. The most commonly studied outcomes were annoyance (23 papers) and sleep disturbance (11 papers). Other reactions were well-being, activity disturbance and use of living environment. No studies including physiological or disease measures were identified. The most commonly used study design was a written survey. Studies were methodologically diverse and it was not possible to conduct a formal meta-analysis. Annoyance was not necessarily decreased by reducing noise exposure. Non-acoustical factors influenced annoyance ratings and some of these were not identical to those in steady state conditions. There was insufficient evidence to recommend sleep disturbance as an alternative measure of reactions in changed noise conditions.

CONCLUSIONS

Surveys of health effects in changed noise situations should be conducted both before and after the change. Annoyance as a reaction indicator should be evaluated with caution as non-acoustical factors play an important role in annoyance ratings. Technical interventions reducing noise levels may therefore not have impacts on annoyance proportionate to their impacts on sound levels. Further studies, investigating impacts on health endpoints (e.g. blood pressure) in changed noise situations are needed.

Trends in aircraft noise annoyance: the role of study and sample characteristics

Recently, it has been suggested that the annoyance of residents at a given aircraft noise exposure level increases over the years. The objective of the present study was to verify the hypothesized trend and to identify its possible causes. To this end, the large database used to establish earlier exposure-response relationships on aircraft noise was updated with original data from several recent surveys, yielding a database with data from 34 separate airports. Multilevel grouped regression was used to determine the annoyance response per airport, after which meta-regression was used to investigate whether study characteristics could explain the heterogeneity in annoyance response between airports. A significant increase over the years was observed in annoyance at a given level of aircraft noise exposure. Furthermore, the type of annoyance scale, the type of contact, and the response percentage were found to be sources of heterogeneity. Of these, only the scale factor could statistically account for the trend, although other findings rule it out as a satisfactory explanation. No evidence was found for increased self-reported noise sensitivity. The results are of importance to the applicability of current exposure-annoyance relationships for aircraft noise and provide a basis for decisions on whether these need to be updated.

The Norwegian Façade Insulation Study: the efficacy of façade insulation in reducing noise annoyance due to road traffic

The efficacy of façade insulation in providing an improved indoor noise environment and in reducing indoor noise annoyance was examined in a socio-acoustic before-and-after study with a control group. An average equivalent noise reduction inside the dwellings of 7 dB was obtained from the façade insulation. Whereas 42% of the respondents were highly annoyed in the before-situation, this dropped to 16% in the after study. The conclusion is therefore that the façade insulation provided a substantial improvement in the indoor noise environment. The advantage with respect to indoor noise annoyance, of having the bedroom facing the least noise-exposed side of the dwelling corresponded to a 6 dB noise reduction. The changes in annoyance from noise reduction due to the façade insulation were in accordance with what would be expected from the exposure-response curves obtained in the before-situation. A total of 637 respondents participated in the before-study. Of these, 415 also participated in the after study. Indoor and outdoor noise exposure calculations for each of the dwellings were undertaken before and after the façade insulation was implemented.

Effects of changed aircraft noise exposure on experiential qualities of outdoor recreational areas

The literature indicates that sound and visual stimuli interact in the impression of landscapes. This paper examines the relationship between annoyance with sound from aircraft and annoyance with other area problems (e.g., careless bicycle riding, crowding, etc.), and how changes in noise exposure influence the perceived overall recreational quality of outdoor recreational areas. A panel study (telephone interviews) conducted before and after the relocation of Norway's main airport in 1998 examined effects of decreased or increased noise exposure in nearby recreational areas (n = 591/455). Sound from aircraft annoyed the largest proportion of recreationists, except near the old airport after the change. The decrease in annoyance with sound from aircraft was accompanied by significant decreases in annoyance with most of the other area problems. Near the new airport annoyance with most factors beside sound from aircraft increased slightly, but not significantly. A relationship between aircraft noise annoyance and perceived overall recreational quality of the areas was found.

Response to a change in transport noise exposure: a review of evidence of a change effect

Environmental appraisals of transport infrastructure plans are generally conducted in situations where there will be a step change, or an abrupt change, in noise exposure. While there has been a number of studies of response to step changes in exposure, and seven previous reviews of subsets of these studies, understanding of human response to a change in noise exposure remains limited. Building largely on these previous reviews, this paper examines the evidence that when noise exposure is changed, subjective reaction may not change in the way that would be predicted from steady-state exposure-response relationships. The weight of evidence, while not incontrovertible, is that when exposure changes, responses show an excess response compared to responses predicted from steady-state exposure-response relationships. That is, there is a change effect in addition to an exposure effect--at least for road studies and at least where the change in exposure results from changes at the source. Further, there appears to be little, if any, adaptation of this excess response with time.