Transportation Noise Sources Research Articles

Estimating community tolerance for wind turbine noise annoyance

A-weighted WTN contributed less than 10% to the strength of the multiple regression model developed for wind turbine noise (WTN) annoyance in Health Canada’s Community Noise and Health Study (CNHS). Improvements required consideration of non-LAeq variables unknown or even inapplicable beyond the CNHS. To facilitate cross-study comparisons, an analysis of WTN annoyance was conducted based on the community tolerance level (CTL) model. The rate of increase in WTN annoyance was effectively estimated using a loudness function, as shown in Eq. (1). %HA = 100 exp (-(1/[10((DNL-CTL + 5.306)/10)]0.3)). (1) By convention, CTL is the DNL from Eq. (1) where 50% of the community would be highly annoyed. The CTL for WTN annoyance from field studies published to date ranges from 57.1 to 64.6 DNL (mean = 62, σ = 3). CTL values developed by others for transportation noise sources suggest that, on average, communities are between 11 dB and 26 dB less tolerant of WTN than of other sources, depending on the source. Confidence in these results should increase as future studies in this area produce additional estimates for the relationship between WTN level and the prevalence of high annoyance. The CTL analytical methods, assumptions, strengths, and limitations are presented.

Transportation noise exposure and cardiovascular mortality: a nationwide cohort study from Switzerland.

Most studies published to date consider single noise sources and the reported noise metrics are not informative about the peaking characteristics of the source under investigation. Our study focuses on the association between cardiovascular mortality in Switzerland and the three major transportation noise sources-road, railway and aircraft traffic-along with a novel noise metric termed intermittency ratio (IR), expressing the percentage contribution of individual noise events to the total noise energy from all sources above background levels. We generated Swiss-wide exposure models for road, railway and aircraft noise for 2001. Noise from the most exposed façade was linked to geocodes at the residential floor height for each of the 4.41 million adult (>30y) Swiss National Cohort participants. For the follow-up period 2000-2008, we investigated the association between all noise exposure variables [Lden(Road), Lden(Rail), Lden(Air), and IR at night] and various cardiovascular primary causes of death by multipollutant Cox regression models adjusted for potential confounders including NO2. The most consistent associations were seen for myocardial infarction: adjusted hazard ratios (HR) (95% CI) per 10dB increase of exposure were 1.038 (1.019-1.058), 1.018 (1.004-1.031), and 1.026 (1.004-1.048) respectively for Lden(Road), Lden(Rail), and Lden(Air). In addition, total IR at night played a role: HRs for CVD were non-significant in the 1st, 2nd and 5th quintiles whereas they were 1.019 (1.002-1.037) and 1.021 (1.003-1.038) for the 3rd and 4th quintiles. Our study demonstrates the impact of all major transportation noise sources on cardiovascular diseases. Mid-range IR levels at night (i.e. between continuous and highly intermittent) are potentially more harmful than continuous noise levels of the same average level.

Source-specific transportation noise mortality from heart failure and myocardial infarction in Switzerland

Introduction: Evidence for an association between cardiovascular diseases (CVD) and transportation noise is growing. While the bulk of studies published to date consider noise sources separately, the typical noise metrics do not inform about the peaking characteristics of the noise source. Our study focuses on the association of the three major transportation noise sources – aircraft, railway and road – along with a novel noise metric termed intermittency ratio (IR, % contribution of individual events in the total noise level from all sources above a certain threshold) with CVD mortality in Switzerland. Methods: In the SiRENE project, we modeled a Swiss-wide noise exposure database for each building at each floor and façade. We geographically linked participants of the Swiss National Cohort (SNC) to the noise database. Noise exposure was assigned to 4.54 mil adult participants of the SNC for the period 2000 to 2008. We selected the maximum Lden values by source and total IR at the floor of residence. The association between noise exposure and heart failure (HF) and myocardial infarction (MI) was investigated by cox regression in multipollutant models adjusted for potential confounders and NO2 exposure. Results: 172025 cases of CVD as primary cause of death were reported, from which 9.4% and 12% died of heart failure and myocardial infarction. Hazard ratios (95% CI) per 10dB(A) increase of exposure for HF were 1.02 (1.01-1.04), 1.06 (1.04-1.08) and 1.06 (1.03-1.08) for Lden-rail, Lden-road, and Lden-air, while for MI they were 1.01 (0.99-1.02), 1.04 (1.02-1.06) 1.02 (1.00-1.04), and 1.01 (1.00-1.02) for Lden-rail, Lden-road, Lden-air and IR. Conclusion: Our study demonstrates the impact of all major transportation noise sources on CVD mortality. For MI, the degree of intermittency was found to be relevant in addition to Lden. This finding is relevant for protection policy of various noise sources with different characteristics.

Sleep Disturbance from Road Traffic, Railways, Airplanes and from Total Environmental Noise Levels in Montreal.

The objective of our study was to measure the impact of transportation-related noise and total environmental noise on sleep disturbance for the residents of Montreal, Canada. A telephone-based survey on noise-related sleep disturbance among 4336 persons aged 18 years and over was conducted. LNight for each study participant was estimated using a land use regression (LUR) model. Distance of the respondent’s residence to the nearest transportation noise source was also used as an indicator of noise exposure. The proportion of the population whose sleep was disturbed by outdoor environmental noise in the past 4 weeks was 12.4%. The proportion of those affected by road traffic, airplane and railway noise was 4.2%, 1.5% and 1.1%, respectively. We observed an increased prevalence in sleep disturbance for those exposed to both rail and road noise when compared for those exposed to road only. We did not observe an increased prevalence in sleep disturbance for those that were both exposed to road and planes when compared to those exposed to road or planes only. We developed regression models to assess the marginal proportion of sleep disturbance as a function of estimated LNight and distance to transportation noise sources. In our models, sleep disturbance increased with proximity to transportation noise sources (railway, airplane and road traffic) and with increasing LNight values. Our study provides a quantitative estimate of the association between total environmental noise levels estimated using an LUR model and sleep disturbance from transportation noise.

Dose-effect relationships for annoyance due to road traffic noise: Multi-level regression and consideration of noise sensitivity

An in situ survey was performed in eight French cities in 2012 to study the annoyance due to combined transportation noise sources. The European Union dose-effect relationships were compared to these new survey data for noise annoyance due to road traffic noise. The measured annoyance was not satisfactorily predicted by these curves: only the percentages of people highly annoyed by road traffic noise was well predicted. Following a multi-level regression as used to construct the European Union dose-effect relationships, new dose-effect relationships were proposed. These new dose-effect relationships enabled a better calculation of noise annoyance due to road traffic noise. Finally, a methodology to consider noise sensitivity in the computation and the percentage of people sensitive to noise in the results is proposed, as this non-acoustical factor is well known to influence noise annoyance. However, the results showed that taking into account such variable did not enable to enhance the dose-effect relatio...

Personal and situational variables associated with wind turbine noise annoyance.

The possibility that wind turbine noise (WTN) affects human health remains controversial. The current analysis presents results related to WTN annoyance reported by randomly selected participants (606 males, 632 females), aged 18-79, living between 0.25 and 11.22 km from wind turbines. WTN levels reached 46 dB, and for each 5 dB increase in WTN levels, the odds of reporting to be either very or extremely (i.e., highly) annoyed increased by 2.60 [95% confidence interval: (1.92, 3.58), p < 0.0001]. Multiple regression models had R(2)'s up to 58%, with approximately 9% attributed to WTN level. Variables associated with WTN annoyance included, but were not limited to, other wind turbine-related annoyances, personal benefit, noise sensitivity, physical safety concerns, property ownership, and province. Annoyance was related to several reported measures of health and well-being, although these associations were statistically weak (R(2 )< 9%), independent of WTN levels, and not retained in multiple regression models. The role of community tolerance level as a complement and/or an alternative to multiple regression in predicting the prevalence of WTN annoyance is also provided. The analysis suggests that communities are between 11 and 26 dB less tolerant of WTN than of other transportation noise sources.

Statistical modeling of the spatial variability of environmental noise levels in Montreal, Canada, using noise measurements and land use characteristics.

The availability of noise maps to assess exposure to noise is often limited, especially in North American cities. We developed land use regression (LUR) models for LAeq24h, Lnight, and Lden to assess the long-term spatial variability of environmental noise levels in Montreal, Canada, considering various transportation noise sources (road, rail, and air). To explore the effects of sampling duration, we compared our LAeq24h levels that were computed over at least five complete contiguous days of measurements to shorter sampling periods (20 min and 24 h). LUR models were built with General Additive Models using continuous 2-min noise measurements from 204 sites. Model performance (adjusted R2) was 0.68, 0.59, and 0.69 for LAeq24h, Lnight, and Lden, respectively. Main predictors of measured noise levels were road-traffic and vegetation variables. Twenty-minute non-rush hour measurements corresponded well with LAeq24h levels computed over 5 days at road-traffic sites (bias: -0.7 dB(A)), but not at rail (-2.1 dB(A)) nor at air (-2.2 dB(A)) sites. Our study provides important insights into the spatial variation of environmental noise levels in a Canadian city. To assess long-term noise levels, sampling strategies should be stratified by noise sources and preferably should include 1 week of measurements at locations exposed to rail and aircraft noise.

Annoyance from Road Traffic, Trains, Airplanes and from Total Environmental Noise Levels.

There is a lack of studies assessing the exposure-response relationship between transportation noise and annoyance in North America. Our aims were to investigate the prevalence of noise annoyance induced by road traffic, trains and airplanes in relation to distance to transportation noise sources, and to total environmental noise levels in Montreal, Canada; annoyance was assessed as noise-induced disturbance. A telephone-based survey among 4336 persons aged >18 years was conducted. Exposure to total environmental noise (A-weighted outdoor noise levels—LAeq24h and day-evening-night equivalent noise levels—Lden) for each study participant was determined using a statistical noise model (land use regression—LUR) that is based on actual outdoor noise measurements. The proportion of the population annoyed by road traffic, airplane and train noise was 20.1%, 13.0% and 6.1%, respectively. As the distance to major roads, railways and the Montreal International Airport increased, the percentage of people disturbed and highly disturbed due to the corresponding traffic noise significantly decreased. When applying the statistical noise model we found a relationship between noise levels and disturbance from road traffic and total environmental noise, with Prevalence Proportion Ratios (PPR) for highly disturbed people of 1.10 (95% CI: 1.07–1.13) and 1.04 (1.02–1.06) per 1 dB(A) Lden, respectively. Our study provides the first comprehensive information on the relationship between transportation noise levels and disturbance in a Canadian city. LUR models are still in development and further studies on transportation noise induced annoyance are consequently needed, especially for sources other than road traffic.

Gden: An indicator for European noise maps comparison and to support action plans

Ten years after the approval of the Environmental Noise Directive 2002/49/EC (END) a large experience have been acquired to develop noise maps and action plans: the Noise Observation and Information Service for Europe maintained by the European Environment Agency (EEA) on behalf of the European Commission contains all data delivered in accordance with the END by Members States within the first round of implementation of the END. This large database should be useful to evaluate the pollution of Europe and to guide policy makers to establish best practices. However, local procedures and national methods do not permit a direct comparison of data reported. A comparison within agglomerations in EU is here carried out in order to find suitable indicators to identify most polluted cities despite different methods used. Critical and quiet areas have been assessed in action plans, but national laws and requirements are various, as different indicators used for their identification. The analysis was performed on noise exposure classes distribution, grouping them together using Gden and Gnight indicators to offer a new tool for presenting noise maps of the cities to the public permitting their comparison and for drawing detailed action plans. Strong relationship between these indicators and highly annoyed and highly sleep-disturbed people percentages are obtained. Furthermore, a comparison between Gden and Qcity Noise Scoring for local hot spot identification is carried out for the agglomeration of Pisa, where different transportation noise sources are present. The final goal is to define faster methods for suitable indicators calculation in hot spot identifications.

Do recent findings on jet noise answer aspects of the Schultz curve?

Recent research efforts on nonlinear propagation from high performance jet aircraft have revealed an interesting challenge to predicting community response. This challenge focuses on receiver perception of these unique acoustical signals, which contain acoustical shocks that appear to increase their relative loudness and/or noisiness. This current finding suggests a need for an improved description of a receiver perception of the loudness of these signals in order to improve the assessment of noise impacts from these aircraft. Looking backwards, an interesting question emerges: did the earlier low bypass jet engines on commercial and transport aircraft also include these acoustical shocks? If they did contain these features, then the perceptual differences observed between aircraft and other transportation noise sources may be partially explained.

Acoustic design of a new elementary school to meet high performance prerequisites using a school districts base design: Predictions and results from commissioning

An architectural firm was selected to design a new elementary school using the school district’s standard building, but with modifications to meet the prerequisites of the Collaborative for Performance Schools (CHPS). Two acoustic prerequisites are a part of the CHPS programs including a background limit of 45 dB(A) and a reverberation time of 0.6 seconds. A 2-story design forms the basis of design. First tests were done at an existing elementary school with the same design. Acoustical recommendations for wall designs, room finishes and HVAC design were incorporated into the design and construction of the new school. The school was not near significant transportation noise sources. After construction was mostly complete, tests were done to learn the sound transmission loss of walls and floor/ceiling systems. Reverberation time tests and background sound levels were measured after construction was complete. Background sound met design goals in all but one space except for the sound generated by a wind turbine mounted on one end of the buildings. This was added by the schools Principal during the latter part of construction without consulting everyone. This proved to be a significant source that had to be removed.

Tsinghua University student design competition—Schools

Armstrong (China) Investment Co., Ltd., with support from Tsinghua University sponsored a school design competition, and this represents the winning student entry. This competition was intended to encourage students to express their knowledge of architectural acoustics and noise control in the design of a school in which acoustical considerations are of significant importance. Design included considerations of 1) the general architectural building design including both shape and location of the building relative to transportation noise sources, and 2) the specific architectural acoustic design of rooms, including noise control both within and between rooms. The design scenario was for a new primary school designed to replace an older school building at a site near Tsinghua University. The primary school will include grade levels from 1 to 6, with approximately 1000 pupils. This school building will include normal classrooms (number and size based on student population and design standards), cafeteria, auditorium, library, music rooms, gym, dancing room, etc, as are normally found in such a primary school. The school will consist of a single building, which may be a multi-level building.

Tongji University student design competition—Schools

Armstrong (China) Investment Co., Ltd., with support from Tongji University sponsored a school design competition, and this represents the winning student entry. This competition was intended to encourage students to express their knowledge of architectural acoustics and noise control in the design of a school in which acoustical considerations are of significant importance. Design included considerations of 1) the general architectural building design including both shape and location of the building relative to transportation noise sources, and 2) the specific architectural acoustic design of rooms, including noise control both within and between rooms. The design scenario was for a new primary school designed to replace an older school building at a site near Tongji University. The primary school will include grade levels from 1 to 6, with approximately 1000 pupils. This school building will include normal classrooms (number and size based on student population and design standards), cafeteria, auditorium, library, music rooms, gym, dancing room, etc, as are normally found in such a primary school. The school will consist of a single building, which may be a multi-level building.

A re-analysis of Day-Night Sound Level (DNL) as a function of population density in the United States

This paper focuses on a re-analysis and updating of the 1974 report by the U.S. Environmental Protection Agency entitled: Population Distribution of the United Sates as a Function of Outdoor Noise Level, and commonly known as the 100-site survey. New data, about half of which were gathered throughout the country during 2008 and 2009 and about half of which were gathered in the Baltimore area in about 1998, are presented in this paper, where these different data sets are compared one to one another, and where the total combined data set in terms of the day-night sound level (abbreviated DNL and symbolized Ldn) is examined as a function of population density. The main conclusions are that the original function in the EPA report yields results that are 3 dB higher than results obtained in a free-field situation, primarily because the measurements in that study used a microphone supported on a pole and at a distance of 1.8 m (6 ft) from the facade of the building. The new data confirm that the EPA predictions are 3 dB higher than those obtained for a free-field situation. A second main conclusion is that there is neither indication of any significant increase in overall ambient community noise exposure over the past 35 years, nor is there indication of any significant decrease in overall ambient community noise exposure despite 35 years of technological noise control improvements on transportation and other noise sources.

The influence of binaural effects on annoyance for transportation noise

A laboratory study was conducted to identify the significance of the binaural effect on annoyance by transportation noise. There were 377 participants (240 male and 137 female). Every participant marked the annoyance score (from 0 to 10) for each stimulus on their questionnaire. All of data were divided into four groups according to four types of transportation noise sources. The difference in the mean annoyance scores between subgroups according to sound recording/ playback techniques was statistically significant in the four noise groups. Stepwise multiple regression analysis was conducted. Using a regression model, predictions of L Aeq , Technique and their interaction term (L Aeq *Technique) involving dummy variable were made. In spite of some limitations of the process of the laboratory test, meaningful results were acquired. This study showed that the binaural effect was one of the acoustical factors modifying annoyance, and quantitative expression of binaural effect is suggested. Annoyance was explained by L Aeq and an interaction term in the resultant model functions for the four noise sources. Regression coefficients of the interaction term for each model equation were almost the same, which explained the extent of the binaural effect. The binaural effect was defined as the difference of annoyance variations between two sub-groups when L Aeq varies by ΔL Aeq from the specified noise level. The binaural effect was expressed as 0.01ΔL Aeq on the basis of a 0 to 10 annoyance scale.

Evaluation of loudness-level weightings for assessing the annoyance of environmental noise.

Assessment of the annoyance of combined noise environments has been the subject of much research and debate. Currently, most countries use some form of the A-weighted equivalent level (ALEQ) to assess the annoyance of most noises. It provides a constant filter that is independent of sound level. Schomer [Acust. Acta Acust. 86(1), 49-61 (2000)] suggested the use of the equal loudness-level contours (ISO 226, 1987) as a dynamic filter that changes with both sound level and frequency. He showed that loudness-level-weighted sound-exposure level (LLSEL) and loudness-level-weighted equivalent level (LL-LEQ) can be used to assess the annoyance of environmental noise. Compared with A-weighting, loudness-level weighting better orders and assesses transportation noise sources, sounds with strong low-frequency content and, with the addition of a 12-dB adjustment, it better orders and assesses highly impulsive sounds vis-a-vis transportation sounds. This paper compares the LLSEL method with two methods based on loudness calculations using ISO 532b (1975). It shows that in terms of correlation with subjective judgments of annoyance-not loudness-the LLSEL formulation performs much better than do the loudness calculations. This result is true across a range of sources that includes aircraft, helicopters, motor vehicles, trains, and impulsive sources. It also is true within several of the sources separately.

The community impact of rogue transportation sources

This study investigates the contributions of atypical transportation noise sources to community noise and relates these contributions to policymaking and resource allocation. Small percentages of aircraft and surface transportation vehicles make a significant contribution to noise levels as measured by day-night sound level and other descriptors. Rogue sources are loosely defined in this study as anomalous sources that have a large impact on community noise. Included are sources that do not comply with regulatory standards due to intentional modifications or due to failure of noise suppression components. Also included are sources that produce noise levels well above reasonably attainable levels despite attainment of regulatory standards. Rogue source identification and assessment can be a component in policymaking and resource allocation. Cost savings can be realized by reducing noise at the source vice by the path. For instance, surface transportation noise standards based on best-available technology and vigorous enforcement can be more cost-effective than erection of noise barriers. In this case, the cost is borne by the offender rather than by the community at-large. The authors analyze and quantify the noise contribution of rogue sources and suggest appropriate noise mitigation.

Development of a curve to predict community annoyance due to transportation noise exposure

This paper presents a brief review of the history of the development of a curve to predict community annoyance in response to transportation noise sources beginning with the original ‘‘Schultz curve’’ [J. Acoust. Soc. Am. 64, 377 (1978)]. This seminal article provided the results of a large-scale database meta-analysis (i.e., a secondary analysis of previously published data) using data from the 11 published transportation-elated community annoyance social surveys. The Schultz curve, which relates general transportation noise exposure (in terms of day–night average sound level, DNL) and the percent of a community ‘‘highly annoyed’’ (%HA) has been used for decades in environmental impact analyses in much of the world. The community annoyance database used by Schultz has been updated with additional social survey data, nearly tripling its original size in the initial Fidell et al. [J. Acoust. Soc. Am. 89, 221–233 (1991)] analysis. A more recent version of this meta-analysis by Finegold et al. [Noise Control Eng. 42(1), 25–30 (1994)] differs from the Fidell et al. analysis on several technical issues and includes 400 data points from 22 international social surveys. The results of the Finegold et al. analysis have recently been adopted as part of a U.S. standard on environmental noise (ANSI S12.9-1996/Part 4). This paper reviews the details of this meta-analysis.

Exposure-response relationships for transportation noise.

This article presents synthesis curves for the relationship between DNL and percentage highly annoyed for three transportation noise sources. The results are based on all 21 datasets examined by Schultz [J. Acoust. Soc. Am. 64, 377-405 (1978)] and Fidell et al. [J. Acoust. Soc. Am. 89, 221-233 (1991)] for which acceptable DNL and percentage highly annoyed measure could be derived, augmented with 34 datasets. Separate, nonidentical curves were found for aircraft, road traffic, and railway noise. A difference between sources was found using data for all studies combined and for only those studies in which respondents evaluated two sources. The latter outcome strengthens the conclusion that the differences between sources cannot be explained by differences in study methodology.

Nighttime sleep disturbance in residential communities—A review of recent U.S. field research and a recommended new dose–response relationship

This paper provides a brief review of field research on nighttime sleep disturbance in residential communities which has been conducted in the United States over nearly the past decade. It compares the research methodology for studying sleep disturbance that has evolved during this series of research projects with the research approaches predominantly used in Europe. The focus is on transportation noise sources, primarily aircraft noise. It also offers a new dose–response relationship based primarily on the U.S. field data collected around civilian airports and military airbases. The new sleep disturbance prediction curve is recommended as an update to the interim curve adopted by the Federal Interagency Committee on Noise (FICON) in 1992. At that time, there was a lack of consensus concerning whether both laboratory and field research data should be used in the development of a new prediction curve. Thus the FICON curve combined the major field and laboratory data published in the U.S. up to that time in an admittedly interim curve. The currently proposed new prediction curve uses only data from field studies and incorporates some of the European research data.