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Atmospheric turbulence causes well-audible fluctuations in sound amplitude as it propagates through the atmospheric boundary layer. However, the best currently available theoretical model describing amplitude fluctuations is limited to relatively short propagation distances and weak turbulence. This article presents a semi-empirical model for predicting the standard deviation of amplitude fluctuations, combining the existing theoretical model of Ostashev and Wilson with empirical data. Leveraging a dataset of over 5000 aircraft flyovers across diverse meteorological conditions, the model incorporates factors such as frequency- and distance-dependent saturation of amplitude fluctuations, an effective propagation length based on the boundary layer height, turbulence decay time during transitional states of the atmosphere, and turbulence production by nocturnal low-level-jets. The mean absolute error of the semi-empirical model compared to the measurements is 0.4 dB. The application of the semi-empirical model to aircraft auralization is demonstrated for a flyover in two meteorological conditions. The findings will enhance the modeling of outdoor sound propagation for elevated sound sources like aircraft and wind turbines. Enhanced modeling of these fluctuations can considerably improve the realism of the listening experience in aircraft flyover auralization. Further, it helps estimating the measurement uncertainty in measured aircraft noise, particularly for maximum levels.

Noise from unmanned aerial vehicles, commonly referred to as "drones," will likely shape our acoustic environment in the near future. Yet, reactions of the population to this new noise source are still little explored. The objective of this study was to investigate short-term noise annoyance reactions to drones in a controlled laboratory experiment. Annoyance to (i) two quadcopters of different sizes in relation to common contemporary transportation noise sources (jet aircraft, propeller aircraft, helicopters, single car passbys), and (ii) different drone maneuvers (takeoff; landing; high, medium, and low flybys) flown at different speeds and elevations was systematically assessed. The results revealed that, at the same sound exposure level, drones are perceived as substantially more annoying than other airborne vehicles and passenger cars. Furthermore, for drone maneuvers, landings, and takeoffs are more annoying than flybys, as are maneuvers flown at low speed. Different loudness metrics (LAE, LDE, effective perceived noise level, psychoacoustic loudness level) accounted for drone noise annoyance ratings to an equal degree. An analysis of psychoacoustic parameters highlighted the significant link between drone noise annoyance and tonality, sharpness, and loudness level. The results suggest a different perception and an increased annoyance potential of drones, which will likely require specifically tailored legislation. [ABSTRACT FROM AUTHOR]

Aircraft noise emissions affect societies around the world by impacting the population's health and land use planning. This calls for simulation tools able to predict these types of noise emissions with high accuracy. A crucial aircraft parameter to achieve satisfying precision is the rotating frequency of the low-pressure shaft of the turbofan engine, called N1. N1 determines the engine's power use and is here estimated acoustically from ground-based microphones. A new method for dynamic N1 estimation is presented, which is more robust as compared to earlier approaches. It makes use of different aircraft sound characteristics and combines two methods. The first method tracks multiple fan tone harmonics over time within a de-Dopplerized sound pressure spectrogram. This frequency-tracking task is solved by dynamic programming to find the global optimum. The second method relates to buzz-saw noise, and is thus applied to departures only. The buzz-saw fundamental frequency is estimated in the cepstral domain. Both submethods are separately validated and assessed with concurrent sound pressure measurements and flight deck recording data of N1. The new robust N1 estimation method will be applied in noise measurement campaigns with the goal of improving current aircraft noise emission models. [ABSTRACT FROM AUTHOR]

Phased microphone array methods are increasingly used to localize and quantify noise sources of aircraft under flight condition. However, beamforming results suffer from loss of image resolution and corruption of sound levels due to atmospheric turbulence causing coherence loss between microphones. A synthesis method is presented that reproduces these effects in a virtual environment. Sound propagation through turbulent atmosphere is described by models by Ostashev and Wilson and by von Kármán turbulence spectra. Spatial coherence is calculated based on the parabolic equation for statistically inhomogeneous, isotropic turbulence. Decorrelation of signals is achieved by time-varying mixing of mutually independent signals with identical PSD based on coherence factors. The concept of auralization is employed to account for propagation delay, geometrical spreading, Doppler effect, air absorption, and ground effect. The application is demonstrated for a virtual 56 m aperture microphone array. The impact of different meteorological conditions on the beamforming and deconvoluted results are presented. For increasing turbulence strength, the results show decreasing sound levels and increasingly blurred images. The proposed method allows us to reproduce the effects of turbulence-induced coherence loss in phased microphone array measurements and to optimize array designs and algorithms in a virtual, controllable environment. [ABSTRACT FROM AUTHOR]

Traffic noise is the perpetual form of environmental pollution adversely affecting human health in urban environments. This literature review, intended for pavement researchers and professionals, looks at the continuously evolving low-noise asphalt pavement technologies and the techniques which can be used to evaluate them. Test methods for determining the acoustical properties of asphalt pavements are reviewed, in both the laboratory and field environments. The Close-Proximity (CPX) method is the most commonly used field test for pavement acoustics, followed by the Statistical Pass-By (SPB) and On-Board Sound Intensity (OBSI) methods. SPB seems is the most comprehensive methods, while the CPX is more practical. Methods for measuring the acoustical properties in the laboratory include the impedance tube for sound absorption and laboratory pavement noise simulators; with only the larger drum methods being able to produce conditions similar to in-situ. Methods for noise-relevant non-acoustical characteristics like surface texture, porosity and airflow resistivity were also reviewed. Optimizing surface texture at the macro-scale was found to be important in reducing tire/road noise. For pavement types, porous asphalt concrete (PAC) and its variants result in low-noise properties the most reliably, while having some drawbacks in durability and maintenance. Finally, various acoustical performance prediction models were discussed. [ABSTRACT FROM AUTHOR]

Residents around airports are impacted by noise produced by civil aircraft operations. With the aim of reducing the negative effects of noise, new low-noise aircraft concepts and flight procedures are being developed. The design processes and the assessments of design variants can be supported by auralization of virtual flyovers. The plausibility of auralized aircraft is increased by considering the effects of atmospheric turbulence on sound propagation. This paper presents a simple approach to include turbulence-induced coherence loss in ground effect. Compared to earlier approaches, the proposed model is closer to the physical mechanisms. It is based on the von Kármán turbulence spectrum and a time-variant partial decorrelation filter. The application of the model to jet aircraft flyovers revealed audible improvements by reducing unnatural flanging. The proposed model increases the accuracy and plausibility of aircraft flyover auralizations. It will thus be applied in the perception-based evaluation of future aircraft concepts. [ABSTRACT FROM AUTHOR]

BACKGROUND: The impact of different transportation noise sources and noise environments on arterial stiffness remains unknown. Objectives: We evaluated the association between residential outdoor exposure to annual average road, railway, and aircraft noise levels, total noise intermittency (IR), and total number of noise events (NE) and brachial-ankle pulse wave velocity (baPWV) following a cross-sectional design. METHODS: We measured baPWV (meters/second) in 2,775 participants (49-81 y old) at the second follow-up (2010-2011) of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). We assigned annual average road, railway, and aircraft noise levels (Ldensource), total day- and nighttime [NE.sub.time] and [IR.sub.time] (percent fluctuation = 0%, none or constant noise; percent fluctuation = 100%, high fluctuation) at the most exposed facade using 2011 Swiss noise models. We applied multivariable linear mixed regression models to analyze associations. RESULTS: Medians [interquartile ranges (IQRs)] were baPWV = 13.4 (3.1) m/s; [Lden.sub.air] (57.6%exposed) =32.8 (8.0) dB; [Lden.sub.rail] (44.6% exposed) =30.0 (8.1) dB; [Lden.sub.road] (99.7% exposed): 54.2 (10.6) dB; [NE.sub.night]=123 (179); [NE.sub.day]=433 (870); [IR.sub.night] = 73% (27); and [IR.sub.day]=63.8% (40.3). We observed a 0.87% (95% CI: 0.31, 1.43%) increase in baPWV per IQR of [Lden.sub.rail], which was greater with [IR.sub.night] > 80% or with daytime sleepiness. We observed a nonsignificant positive association between [Lden.sub.road] and baPWV in urban areas and a negative tendency in rural areas. [NE.sub.night], but not [NE.sub.day], was associated with baPWV. Associations were independent of the other noise sources and air pollution. CONCLUSIONS: Long-term exposure to railway noise, particularly in an intermittent nighttime noise environment, and to nighttime noise events, mainly related to road noise, may affect arterial stiffness, a major determinant of cardiovascular disease. Ascertaining noise exposure characteristics beyond average noise levels may be relevant to better understand noise-related health effects. https://doi.org/10.1289/EHP1136, Introduction There is substantial epidemiological evidence relating long-term exposure to transportation noise with cardiovascular disease (CVD) (Babisch 2014; Vienneau et al. 2015), which is the leading cause of morbidity and [...]

Residents living in the vicinity of airports are exposed to noise from departing and approaching aircraft. Noise may be reduced by introducing novel aircraft technologies into vehicle retrofit, aircraft design and flight procedures. Nowadays, noise assessment and communication of noise are accomplished using conventional noise indicators that consider neither the perception of sound, nor its health effects. To overcome these limitations, this article presents a more comprehensive approach that supports the movement for perception-influenced design in order to reduce the negative environmental impacts and adverse health effects caused by increased air traffic noise. By means of auralization (the acoustical counterpart of visualization), possible future changes can be evaluated by considering the human perception of sound. In this study, in a virtual acoustic environment flyovers of different aircraft types and flight procedures are auralized for ground-based receiver locations, and subsequently evaluated in a psychoacoustic laboratory experiment with respect to short-term noise annoyance. Flight approaches of an existing reference aircraft, a possible low-noise retrofitted vehicle and a future low-noise vehicle design were simulated along standard and tailored flight procedures. To create realistic listening experiences of synthetic flyovers, auralization technologies were further developed regarding source synthesis, transitions between aircraft conditions, sound propagation effects and immersive sound reproduction. Listening experiments revealed significant annoyance reductions for low-noise aircraft types and tailored flight procedures, and that maximum benefit is achieved by the combined optimization of aircraft design and flight procedure. Further, it is shown that spatially distributed receivers need to be considered for a reliable low-noise aircraft technology evaluation. The reduction potential in terms of perceived noise by retrofitting current vehicles and designing new vehicle architectures is thus demonstrated. These findings suggest applying the proposed comprehensive approach to effectively reduce the impact of perceived air traffic noise in the future. Unlabelled Image • A comprehensive approach to reduce aircraft noise annoyance is proposed. • Perception-based evaluation of future low-noise aircraft technologies is affirmed. • Combined optimization of air vehicles and flight procedures is most beneficial. • Reliable optimization requires consideration of several receiver locations. [ABSTRACT FROM AUTHOR]

Aims The present study aimed to disentangle the risk of the three major transportation noise sources—road, railway, and aircraft traffic—and the air pollutants NO2 and PM2.5 on myocardial infarction (MI) mortality in Switzerland based on high quality/fine resolution exposure modelling. Methods and results We modelled long-term exposure to outdoor road traffic, railway, and aircraft noise levels, as well as NO2 and PM2.5 concentration for each address of the 4.40 million adults (>30 years) in the Swiss National Cohort (SNC). We investigated the association between transportation noise/air pollution exposure and death due to MI during the follow-up period 2000–08, by adjusting noise [Lden(Road), Lden(Railway), and Lden(Air)] estimates for NO2 and/or PM2.5 and vice versa by multipollutant Cox regression models considering potential confounders. Adjusting noise risk estimates of MI for NO2 and/or PM2.5 did not change the hazard ratios (HRs) per 10 dB increase in road traffic (without air pollution: 1.032, 95% CI: 1.014–1.051, adjusted for NO2 and PM2.5: 1.034, 95% CI: 1.014–1.055), railway traffic (1.020, 95% CI: 1.007–1.033 vs. 1.020, 95% CI: 1.007–1.033), and aircraft traffic noise (1.025, 95% CI: 1.006–1.045 vs. 1.025, 95% CI: 1.005–1.046). Conversely, noise adjusted HRs for air pollutants were lower than corresponding estimates without noise adjustment. Hazard ratio per 10 μg/m³ increase with and without noise adjustment were 1.024 (1.005–1.043) vs. 0.990 (0.965–1.016) for NO2 and 1.054 (1.013–1.093) vs. 1.019 (0.971–1.071) for PM2.5. Conclusion Our study suggests that transportation noise is associated with MI mortality, independent from air pollution. Air pollution studies not adequately adjusting for transportation noise exposure may overestimate the cardiovascular disease burden of air pollution. [ABSTRACT FROM AUTHOR]

Helicopter noise exhibits distinctive acoustical characteristics (e.g., pulsation) compared to noise from propeller-driven aircraft which contains tonal components. Whereas, at comparable sound exposure levels (LAE), annoyance reactions to these sources might be different, knowledge of potential annoyance differences is scarce. This paper reports a comparison between short-term annoyance reactions to noise from light-weight helicopters and propeller-driven aircraft in a laboratory setup. Stimuli were presented with a 3D sound reproduction system in a listening test facility based on field recordings of takeoffs and landings. Propagation filtering and amplitude changes were carried out to simulate various propagation distances and source levels, covering a reasonable LAE range from 64 to 85 dB(A) for a stimuli length of 24 s. Fifty-six subjects rated their short-term annoyance reactions on the ICBEN 11-point numerical scale. Associations between design variables (source type, procedure, and LAE) and short-term annoyance were explored by means of a linear mixed-effect model. LAE was found to be the major predictor. For the major range of LAE, no significant difference was found between annoyance to noise from the two aircraft types. Observed level differences at equal annoyance ratings were below 1 dB. Furthermore, helicopter landings were found slightly more annoying than helicopter takeoffs. [ABSTRACT FROM AUTHOR]

Textile curtains can be designed to be good sound absorbers. Their acoustical performance, as usually described by the sound absorption coefficient, not only depends on the textile itself but also on the drapery fullness and the backing condition, that is, the spacing between the fabric and a rigid backing wall, or the absence of a backing in the case of a freely hanging curtain. This article reviews existing models to predict the diffuse-field sound absorption coefficient, which to date can only predict the case of flat curtains. A set of existing models is extended to the case of curtains with drapery fullness using a semi-empirical approach. The models consider different backing conditions, including freely hanging curtains. The existing and new models are validated by comparing predicted sound absorption coefficients with data measured in a reverberation room. Hereby, curtains consisting of different fabrics and with different degrees of fullness are considered. Besides situations with rigid backing, also the measurement data of textiles hung freely in space are included in this study. Comparisons reveal a very good agreement between measured and predicted sound absorption coefficients. Compared to currently available commercial sound absorption prediction software that can only handle the situation of flat textiles with rigid backing, the results of the presented models not only show a better agreement with measured data, but also cover a broader range of situations. The presented models are thus well applicable in the design and development of new textiles as well as in the room acoustical planning process. [ABSTRACT FROM AUTHOR]

Background: Epidemiological studies have inconsistently linked transportation noise and air pollution (AP) with diabetes risk. Most studies have considered single noise sources and/or AP, but none has investigated their mutually independent contributions to diabetes risk.Methods: We investigated 2631 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA), without diabetes in 2002 and without change of residence between 2002 and 2011. Using questionnaire and biomarker data, incident diabetes cases were identified in 2011. Noise and AP exposures in 2001 were assigned to participants' residences (annual average road, railway or aircraft noise level during day-evening-night (Lden), total night number of noise events, intermittency ratio (temporal variation as proportion of event-based noise level over total noise level) and nitrogen dioxide (NO2) levels. We applied mixed Poisson regression to estimate the relative risk (RR) of diabetes and their 95% confidence intervals (CI) in mutually-adjusted models.Results: Diabetes incidence was 4.2%. Median [interquartile range (IQR)] road, railway, aircraft noise and NO2 were 54 (10) dB, 32 (11) dB, 30 (12) dB and 21 (15) μg/m3, respectively. Lden road and aircraft were associated with incident diabetes (respective RR: 1.35; 95% CI: 1.02-1.78 and 1.86; 95% CI: 0.96-3.59 per IQR) independently of Lden railway and NO2 (which were not associated with diabetes risk) in mutually adjusted models. We observed stronger effects of Lden road among participants reporting poor sleep quality or sleeping with open windows.Conclusions: Transportation noise may be more relevant than AP in the development of diabetes, potentially acting through noise-induced sleep disturbances. [ABSTRACT FROM AUTHOR]

Noise exposure-response relationships are used to estimate the effects of noise on individuals or a population. Such relationships may be derived from independent or repeated binary observations, and modeled by different statistical methods. Depending on the method by which they were established, their application in population risk assessment or estimation of individual responses may yield different results, i.e., predict “weaker” or “stronger” effects. As far as the present body of literature on noise effect studies is concerned, however, the underlying statistical methodology to establish exposure-response relationships has not always been paid sufficient attention. This paper gives an overview on two statistical approaches (subject-specific and population-averaged logistic regression analysis) to establish noise exposure-response relationships from repeated binary observations, and their appropriate applications. The considerations are illustrated with data from three noise effect studies, estimating also the magnitude of differences in results when applying exposure-response relationships derived from the two statistical approaches. Depending on the underlying data set and the probability range of the binary variable it covers, the two approaches yield similar to very different results. The adequate choice of a specific statistical approach and its application in subsequent studies, both depending on the research question, are therefore crucial. [ABSTRACT FROM AUTHOR]

Current literature suggests that wind turbine noise is more annoying than transportation noise. To date, however, it is not known which acoustic characteristics of wind turbines alone, i.e., without effect modifiers such as visibility, are associated with annoyance. The objective of this study was therefore to investigate and compare the short-term noise annoyance reactions to wind turbines and road traffic in controlled laboratory listening tests. A set of acoustic scenarios was created which, combined with the factorial design of the listening tests, allowed separating the individual associations of three acoustic characteristics with annoyance, namely, source type (wind turbine, road traffic), A-weighted sound pressure level, and amplitude modulation (without, periodic, random). Sixty participants rated their annoyance to the sounds. At the same A-weighted sound pressure level, wind turbine noise was found to be associated with higher annoyance than road traffic noise, particularly with amplitude modulation. The increased annoyance to amplitude modulation of wind turbines is not related to its periodicity, but seems to depend on the modulation frequency range. The study discloses a direct link of different acoustic characteristics to annoyance, yet the generalizability to long-term exposure in the field still needs to be verified. [ABSTRACT FROM AUTHOR]

While the technique of auralization has been in use for quite some time in architectural acoustics, the application to environmental noise has been discovered only recently. With road traffic noise being the dominant noise source in most countries, particular interest lies in the synthesis of realistic pass-by sounds. This article describes an auralizator for pass-bys of accelerating passenger cars. The key element is a synthesizer that simulates the acoustical emission of different vehicles, driving on different surfaces, under different operating conditions. Audio signals for the emitted tire noise, as well as the propulsion noise are generated using spectral modelling synthesis, which gives complete control of the signal characteristics. The sound of propulsion is synthesized as a function of instantaneous engine speed, engine load and emission angle, whereas the sound of tires is created in dependence of vehicle speed and emission angle. The sound propagation is simulated by applying a series of time-variant digital filters. To obtain the corresponding steering parameters of the synthesizer, controlled experiments were carried out. The tire noise parameters were determined from coast-by measurements of passenger cars with idling engines. To obtain the propulsion noise parameters, measurements at different engine speeds, engine loads and emission angles were performed using a chassis dynamometer. The article shows how, from the measured data, the synthesizer parameters are calculated using audio signal processing. [ABSTRACT FROM AUTHOR]

Recently, the accuracy of the parallel transfer matrix method (P-TMM) and the admittance sum method (ASM) in the prediction of the absorption properties of parallel assemblies of materials was investigated [Verdière, Panneton, Elkoun, Dupont, and Leclaire, J. Acoust. Soc. Am. 136, EL90-EL95 (2014)]. It was demonstrated that P-TMM is more versatile than ASM, as a larger variety of different backing configurations can be handled. Here it will be shown that the same universality is offered by the equivalent circuit method. [ABSTRACT FROM AUTHOR]

Public landscape impact assessment of renewable energy installations is crucial for their acceptance. Thus, a sound assessment basis is crucial in the implementation process. For valuing landscape perception, the visual sense is the dominant human sensory component. However, the visual sense provides only partial information about our environment. Especially when it comes to wind farm assessments, noise produced by the rotating turbine blades is another major impact factor. Therefore, an integrated visual and acoustic assessment of wind farm projects is needed to allow lay people to perceive their impact adequately. This paper presents an approach of linking spatially referenced auralizations to a GIS-based virtual 3D landscape model. We demonstrate how to utilize a game engine for 3D visualization of wind parks, using geodata as a modeling basis. In particular, the controlling and recording of specific parameters in the game engine is shown in order to establish a link to the acoustical model. The resulting prototype has high potential to complement conventional tools for an improved public impact assessment of wind farms. [ABSTRACT FROM AUTHOR]

A theoretical model for the oblique incidence sound absorption coefficient of thin woven fabrics backed by an air cavity is presented where the fabric is acoustically described by its specific airflow resistance and its surface mass density. The theoretical model is illustrated by an equivalent electrical circuit and validated in the case of normal sound incidence by experimental results obtained from impedance tube measurements on three fabric types. The influence of the surface mass density on the absorption coefficient is discussed and recommendations for practical applications are derived. Further, a simple formula to predict the specific airflow resistance of woven fabrics based on geometrical parameters is deduced. The normal incidence absorption coefficient and geometrical parameters of a set of 24 fabrics with a large range of interyarn porosities and specific airflow resistances were measured and used to validate the proposed geometry-based model to predict the absorption coefficient. Measured and estimated absorption coefficients show excellent agreement, with mean value and standard deviation of the differences of 0.03 ± 0.10. The model is therefore suitable for the design of new fabrics with an intended absorption coefficient. [ABSTRACT FROM PUBLISHER]

This article presents empirically derived conversion rules between the environmental noise exposure metrics Leq24h, LDay, LEvening, LNight, Ldn, and Lden for the noise sources road, rail and air traffic. It caters to researchers that need to estimate the value of one (unknown) noise metric from the value of another (known) metric, e.g. in the scope of epidemiological meta-analyses or systematic reviews, when results from different studies are pooled and need to be related to one common exposure metric. Conversion terms are derived using two empirical methods a) based on analyzing the diurnal variation of traffic, and b) by analyzing differences between calculated noise exposure metrics. For a) we collected and analyzed diurnal traffic share data from European and US airports as well as data on the diurnal variation of traffic from roads in several European countries and from railway lines in Switzerland which were derived from counting stations and official records. For b) we calculated differences between noise metrics in over 50'000 stratified randomly sampled dwellings in Switzerland. As a result of this exercise, conversion terms, including uncertainty estimates, are systematically tabulated for all variants of the target metrics. Guidance as to the practical applicability of the proposed conversions in different contexts is provided, and limitations of their use are discussed. [ABSTRACT FROM AUTHOR]

Abstract 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. Highlights • Noise annoyance is associated with Lden of road, rail, and aircraft noise exposure. • The degree of intermittency of noise can explain differences in annoyance reactions. • Aircraft noise is more annoying than railway noise and road traffic noise. • We found no empirical basis for a "railway bonus" for noise regulation. [ABSTRACT FROM AUTHOR]

Abstract Background Epidemiological research on transportation noise uses different exposure assessment strategies based on façade point estimates or regulatory noise maps. The degree of exposure measurement error and subsequent potentially biased risk estimates related to exposure definition is unclear. We aimed to evaluate associations between transportation noise exposure and myocardial infarction (MI) mortality considering: assumptions about residential floor, façade point selection (loudest, quietest, nearest), façade point vs. noise map estimates, and influence of averaging exposure at coarser spatial scales (e.g. in ecological health studies). Methods L den from the façade points were assigned to >4 million eligible adults in the Swiss National Cohort for the best match residential floor (reference), middle floor, and first floor. For selected floors, the loudest and quietest exposed façades per dwelling, plus the nearest façade point to the residential geocode, were extracted. Exposure was also assigned from 10 × 10 m noise maps, using "buffers" from 50 to 500 m derived from the maps, and by aggregating the maps to larger areas. Associations between road traffic and railway noise and MI mortality were evaluated by multi-pollutant Cox regression models, adjusted for aircraft noise, NO 2 and socio-demographic confounders, following individuals from 2000 to 2008. Bias was calculated to express differences compared to the reference. Results Hazard ratios (HRs) for the best match residential floor were 1.05 (1.02–1.07) and 1.03 (1.01–1.05) per IQR (11.3 and 15.0 dB) for road traffic and railway noise, respectively. In most situations, comparing the alternative exposure definitions to this reference resulted in attenuated HRs. For example, assuming everyone resided on the middle or everyone on first floor introduced little bias (%Bias in excess risk: −1.9 to 4.4 road traffic and −4.4 to 10.7 railway noise). Using the noise grids generated a bias of approximately −26% for both sources. Averaging the maps at a coarser spatial scale led to bias from −19.4 to −105.1% for road traffic and 17.6 to −34.3% for railway noise and inflated the confidence intervals such that some HRs were no longer statistically significant. Conclusion Changes in spatial scale introduced more bias than changes in residential floor. Use of noise maps to represent residential exposure may underestimate noise-induced health effects, in particular for small-scale heterogeneously distributed road traffic noise in urban settings. Highlights • Source-propagation models at façades are the gold standard for noise exposure. • Influence of assigning exposure in different ways was evaluated. • Exposure definition on health effects was more critical for road vs. rail noise. • Exposure at larger scales introduced more bias and attenuated health estimates. • Façade estimates or fine scale noise maps are recommended. [ABSTRACT FROM AUTHOR]

Abstract Transportation noise leads to sleep disturbance and to psychological and physiological sustained stress reactions, which could impact respiratory health. However, epidemiologic evidence on associations of objective transportation noise exposure and also perceived noise annoyance with respiratory morbidity is limited. We investigated independent associations of transportation noise exposure and noise annoyance with prevalent respiratory symptoms and incident asthma in adults. Using 17,138 observations (from 7049 participants) from three SAPALDIA (Swiss Cohort Study on Lung and Heart Diseases in Adults) surveys, we assessed associations of transportation noise exposure and noise annoyance with prevalent respiratory symptoms, and with incident asthma (in 10,657 nested observations from 6377 participants). Annual day-evening-night transportation noise comprising road, railway and aircraft Lden (Transportation Lden) was calculated for the most exposed façade of participants' residence using Swiss noise models. Transportation noise annoyance was assessed using an 11-point scale, and participants reported respiratory symptoms and doctor-diagnosed asthma at each survey. We estimated associations with transportation Lden (as well as source-specific Lden) and noise annoyance, independent of air pollution and other potential confounders, using mutually-adjusted mixed logistic and Poisson models and applying random intercepts at the level of the participants. Prevalent respiratory symptoms ranged from 5% (nocturnal dyspnoea) to 23% (regular cough/phlegm). Transportation noise annoyance, but not Lden, was independently associated with respiratory symptoms and current asthma in all participants, with odds ratios (OR) and 95% confidence intervals (CI) ranging between 1.03 (95%CI: 1.01, 1.06) and 1.07 (95% CI: 1.04, 1.11) per 1-point difference in noise annoyance. Both noise annoyance and Lden showed independent associations with asthma symptoms among asthmatics, especially in those reporting adult-onset asthma [OR Lden : 1.90 (95% CI: 1.25, 2.89) per 10 dB; p-value of interaction (adult-onset vs. childhood-onset): 0.03; OR noise annoyance : 1.06 (95%CI: 0.97, 1.16) per 1-point difference; p-value of interaction: 0.06]. No associations were found with incident asthma. Transportation noise level and annoyance contributed to symptom exacerbation in adult asthma. This suggests both psychological and physiological noise reactions on the respiratory system, and could be relevant for asthma care. More studies are needed to better understand the effects of objective and perceived noise in asthma aetiology and overall respiratory health. Highlights • We studied association of noise level and annoyance with adult respiratory morbidity. • Noise annoyance was associated with respiratory symptoms and current asthma. • Noise level was only associated with respiratory symptoms in asthmatic participants. • Noise level and annoyance were not associated with the development of asthma. • The results highlight the potential importance of perceived noise and noise annoyance on respiratory health. [ABSTRACT FROM AUTHOR]

Abstract The contribution of different transportation noise sources to metabolic disorders such as obesity remains understudied. We evaluated the associations of long-term exposure to road, railway and aircraft noise with measures of obesity and its subphenotypes using cross-sectional and longitudinal designs. We assessed 3796 participants from the population-based Swiss Cohort Study on Air Pollution and Lung and Heart Diseases (SAPALDIA), who attended the visits in 2001 (SAP2) and 2010/2011 (SAP3) and who were aged 29–72 at SAP2. At SAP2 we measured body mass index (BMI, kg/m2). At SAP3 we measured BMI, waist circumference (centimetres) and Kyle body Fat Index (%) and derived overweight, central and general obesity. Longitudinally for BMI, we derived change in BMI, incidence of overweight and obesity and a 3-category outcome combining the latter two. We assigned source-specific 5-year mean noise levels before visits and during follow-up at the most exposed dwelling façade (Lden, dB), using Swiss noise models for 2001 and 2011 and participants' residential history. Models were adjusted for relevant confounders, including traffic-related air pollution. Exposure to road traffic noise was significantly associated with all adiposity subphenotypes, cross-sectionally (at SAP3) [e.g. beta (95% CI) per 10 dB, BMI: 0.39 (0.18; 0.59); waist circumference: 0.93 (0.37; 1.50)], and with increased risk of obesity, longitudinally (e.g. RR = 1.25, 95% CI: 1.04; 1.51, per 10 dB in 5-year mean). Railway noise was significantly related to increased risk of overweight. In cross-sectional analyses, we further identified a stronger association between road traffic noise and BMI among participants with cardiovascular disease and an association between railway noise and BMI among participants reporting bad sleep. Associations were independent of the other noise sources, air pollution and robust to all adjustment sets. No associations were observed for aircraft noise. Long-term exposure to transportation noise, particularly road traffic noise, may increase the risk of obesity and could constitute a pathway towards cardiometabolic and other diseases. Highlights • Long-term exposure to road traffic noise over time may increase the risk of obesity. • Cross-sectionally, it also relates to higher BMI, waist circumference and body fat. • Cross-sectionally, it also relates to general and central obesity and overweight. • Long-term exposure to railway noise might also relate to risk of overweight. [ABSTRACT FROM AUTHOR]

Abstract Background Epidemiological evidence indicates an association between transportation noise exposure and a higher risk of developing type 2 diabetes. Sleep disturbances are thought to be one of the mechanisms as it is well established that a few nights of short or poor sleep impair glucose tolerance and insulin sensitivity in healthy good sleepers. Objectives The present study aimed to determine the extent to which exposure to nocturnal transportation noise affects glucose metabolism, and whether it is related to noise-induced sleep alterations. Methods Twenty-one young healthy volunteers (nine women) participated in a six-day laboratory study starting with a noise-free baseline night, then four nights sleeping with randomly-presented transportation noise scenarios (three road and one railway noise scenario) with identical average sound level of 45 dB but differing in eventfulness and ending with a noise-free recovery night. Sleep was measured by polysomnography. Glucose tolerance and insulin sensitivity were measured after the baseline, the last noise night and the recovery nights with an oral glucose tolerance test using Matsuda and Stumvoll insulin sensitivity indexes. Eleven participants were assigned a less eventful noise scenario during the last noise night (LE-group), while the other ten had a more eventful noise scenario (ME-group). Baseline metabolic and sleep variables between the two intervention groups were compared using a non-parametric Mann-Whitney U test while mixed models were used for repeated measure analysis. Results All participants had increased glucose AUC (mean ± SE, 14 ± 2%, p < 0.0001) and insulin AUC (55 ± 10%, p < 0.0001) after the last noise night compared to the baseline night. 2 h-glucose level tended to increase only in the ME-group between baseline (5.1 ± 0.22 mmol·L−1) and the last noise night (6.1 ± 0.39 mmol·L−1, condition: p = 0.001, interaction: p = 0.08). Insulin sensitivity assessed with Matsuda and Stumvoll indexes respectively decreased by 7 ± 8% (p = 0.001) and 9 ± 2% (p < 0.0001) after four nights with transportation noise. Only participants in the LE-group showed beneficial effects of the noise-free recovery night on glucose regulation (relative change to baseline: glucose AUC : 1 ± 2%, p = 1.0 for LE-group and 18 ± 4%, p < 0.0001 for ME-group; Stumvoll index: 3.2 ± 2.6%, p = 1.0 for LE-group and 11 ± 2.5%, p = 0.002 for ME-group). Sleep was mildly impaired with increased sleep latency of 8 ± 2 min (<0.0001) and more cortical arousals per hour of sleep (1.8 ± 0.6 arousals/h, p = 0.01) during the last noise night compared to baseline. No significant associations between sleep measures and glucose tolerance and insulin sensitivity were found. Conclusion In line with epidemiological findings, sleeping four nights with transportation noise impaired glucose tolerance and insulin sensitivity. Based on the presented sound exposure, the eventfulness of the noise scenarios seems to play an important role for noise-induced alterations in glucose regulation. However, we could not confirm our hypothesis that transportation noise impairs glucose regulation via deterioration in sleep quality and quantity. Therefore, other factors, such as stress-related pathways, may need to be considered as potential triggers for noise-evoked glucose intolerance in future research. [ABSTRACT FROM AUTHOR]

Background: Most epidemiological noise studies consider 24 h average noise exposure levels. Our aim was to exploratively analyze the impact of noise exposure at different time windows during day and night on cardiovascular mortality.Methods: We generated Switzerland-wide exposure models for road traffic, railway and aircraft noise for different time windows for the year 2001. Combined noise source equivalent continuous sound levels (Leq) for different time windows at the most exposed façade were assigned to each of the 4.41 million Swiss National Cohort adult participants. Follow-up period was from 2000 to 2008. Hazard ratios (HR) of noise effects on various cardiovascular primary causes of death were computed by Cox regression models adjusted for potential confounders and NO2 levels.Results: For most cardiovascular causes of death we obtained indications for a diurnal pattern. For ischemic heart disease the highest HR was observed for the core night hours from 01 h to 05 h (HR per standard deviation of Leq: 1.025, 95% CI: 1.016-1.034) and lower HR for the daytime 07 h to 19 h (1.018 [1.009-1.028]). Heart failure and daytime Leq yielded the highest HR (1.047 [1.027-1.068]).Conclusion: For acute cardiovascular diseases, nocturnal intermittent noise exposure tended to be more relevant than daytime exposure, whereas it was the opposite for chronic conditions such as heart failure most strongly associated with continuous daytime noise. This suggests that for acute diseases sleep is an important mediator for health consequences of transportation noise. [ABSTRACT FROM AUTHOR]

Abstract: The sleep disturbing effects of nocturnal ambient non-traffic related noises such as bell strokes emitted from church bell towers on nearby residents are presently unknown. Nonetheless, this specific noise source is suspected to cause sleep disturbances in a small but qualified minority of people living in the vicinity of the bell towers that throughout the night indicate the time with bell ringings. A field study was carried out to elucidate whether acoustic properties of such bell strokes relate to awakening and to provide event-related exposure-effect functions between acoustical predictors and awakening probability. Awakening reactions were determined in 27 voluntary subjects, measured in their home setting for four consecutive nights with ambulatory polysomnography (PSG) and concurrent acoustic recordings in- and outside the dwelling. Results indicate that the bell ringing events increase awakenings in a similar fashion as has previously been reported with transportation noise events and that awakening probability first and foremost depends on maximum sound pressure level of an event. The number of bell strokes and the personal variables gender, age, and noise sensitivity did not influence awakening probability significantly. Awakening probability by tendency increased with elapsed time after sleep onset, and was decreased during slow wave sleep and REM sleep compared to S2 sleep. The results suggest that a reduction of the maximum sound pressure level or an interruption of ringings during nighttime might reduce awakenings. The determined exposure–effect relationships are compared with similar functions for impulsive noise and transportation noise, more specifically, aircraft noise. The paper concludes with a few considerations regarding nighttime noise regulation. [Copyright &y& Elsevier]

Chronic exposure to nocturnal transportation noise has been linked to cardiovascular disorders with sleep impairment as the main mediator. Here we examined whether nocturnal transportation noise affects the main stress pathways, and whether it relates to changes in the macro and micro structure of sleep. Twenty-six young healthy participants (12 women, 24.6 ± 0.7 years, mean ± SE) spent five consecutive 24-h days and one last morning in the laboratory. The first (baseline) and last (recovery) nights comprised a quiet ambient scenario. In-between, four different noise scenarios (low/medium/high intermittent road or rail scenarios with an identical equivalent continuous sound level of 45 dB) were randomly presented during the 8-h nights. Participants felt more annoyed from the transportation noise scenarios compared to the quiet ambient scenario played back during the baseline and recovery nights (F 5,117 = 10.2, p < 0.001). Nocturnal transportation noise did not significantly impact polysomnographically assessed sleep macrostructure, blood pressure, nocturnal catecholamine levels and morning cytokine levels. Evening cortisol levels increased after sleeping with highly intermittent road noise compared to baseline (p = 0.002, noise effect: F 4,83 = 4.0, p = 0.005), a result related to increased cumulative duration of autonomic arousals during the noise nights (F 5,106 = 3.4, p < 0.001; correlation: r pearson = 0.64, p = 0.006). Under controlled laboratory conditions, highly intermittent nocturnal road noise exposure at 45 dB increased the cumulative duration of autonomic arousals during sleep and next-day evening cortisol levels. Our results indicate that, without impairing sleep macrostructure, nocturnal transportation noise of 45 dB is a physiological stressor that affects the hypothalamic-pituitary-adrenal axis during the following day in healthy young good sleepers. • Nocturnal transportation noise at 45dB does not alter sleep architecture of healthy subjects. • Highly intermittent nocturnal noise increases next-day evening cortisol levels. • The increase in cortisol is related to longer autonomic arousals during sleep. • Nocturnal noise at 45dB does not change blood pressure, catecholamines and cytokines. [ABSTRACT FROM AUTHOR]