Measuring Community Response to Noise-Factors Affecting the Results of Annoyance Surveys.

Social surveys are conducted to determine how annoyed people are in a certain noise situation. The results are typically presented as exposure-response curves showing the percentage of the area population that are highly annoyed as a function of the noise exposure level. It is a well-known fact that the survey results are not only dependent on the accumulated noise exposure, DNL, DENL, or similar, but also on various other factors such as maximum levels, exposure patterns, noise spectra, etc. A re-analysis of previously reported surveys shows that the results are also, to a large extent, dependent on survey-specific factors like the wording of the annoyance questions, how the questionnaires are presented, response scales, methods of scoring highly annoyed, etc. This paper discusses and quantifies the influence of such factors and suggests ways of comparing results from surveys that have been conducted according to different protocols and different analysis methods.

An alternate approach to regulatory analyses of the findings of a 20-airport social survey.

Miller, Czech, Hellauer, Nicholas, Lohr, Jodts, Broene, Morganstein, Kali, Zhu, Cantor, Hudnall, and Melia [(2021). HMMH Report 308520.004.001] reported the findings of a 20-airport social survey sponsored by the U.S. Federal Aviation Administration that had been designed and conducted six years earlier. Their primary analyses yielded FICON (1992) style (national average and airport-specific bivariate logistic regression) functions relating aircraft noise exposure to the prevalence of high annoyance [FICON (1992). "Federal agency review of selected airport noise analysis issues" (Department of Defense, Washington, DC)]. Alternate analyses of these field observations offer pragmatic benefits for regulatory purposes. Community Tolerance Level (CTL) analysis yields a national average exposure-response predictive function that is nearly indistinguishable from that of a bivariate logistic regression function. Since it natively distinguishes dose-related from collective, non-dose influences on annoyance, it also permits a more parsimonious and readily understood account of the association between aircraft noise exposure and annoyance. Within the exposure range of primary contemporary regulatory concern, CTL analysis accounts for as much variance as FICON-style analysis in the association between noise exposure and predicted annoyance; provides a causal basis for regulation; and can be more effectively implemented and defended than a purely correlation-based analysis. In addition, CTL analysis helps to address the substantial disagreement between the findings of the literature and those of national and international technical consensus standards.

Effect of alternate definitions of "high" annoyance on exposure-response functions.

The International Standards Organization (ISO) published Technical Specification (TS) 15666 in 2003 to facilitate the comparison of results from surveys on noise annoyance. This document recommends including two standardized questions with two standardized response scales in all surveys of long-term noise annoyance. A recently revised version of the TS proposes a weighting procedure for the response data to achieve a better similarity between the results from the two questions. This paper analyses the results from 43 surveys conducted according to the ISO/TS 15666 recommendations. It is shown that the average difference in the response to the two annoyance questions is equivalent to a 6 dB shift in the exposure level. The proposed weighting of the verbal response whereby response category 5 (extremely) is counted in full, and category 4 (very) is weighted by a factor 0.4 creates a greater similarity between the two responses. It is important to use a definition of prevalence of high annoyance which matches the one used for the development of the relevant noise regulations.

Assessing community noise annoyance: A review of two decades of the international technical specification ISO/TS 15666:2003.

The robust assessment of noise annoyance is of key importance given that it is the most prevalent community response in populations exposed to environmental noise. In 1993, the International Commission on Biological Effects of Noise Community Response to Noise team began formalizing a standardized methodology for assessing noise annoyance which resulted in reporting guidelines and recommendations later published as a Technical Specification (TS) in 2003 by the International Standards Organization (ISO) [(2003). ISO/TS 15666]. This TS, intended to inform the international community on the quantification of the exposure-response relationship between noise exposure and annoyance, has been in circulation for nearly two decades and was updated in 2021 by ISO [(2021). ISO/TS 15666] by an international working group (ISO TC43/SC1/WG62). This paper reviews use of the 2003 TS, identifies common adaptations in use, and summarizes the revisions. Methodological issues arising from the use of the 5-point verbal and the 11-point numeric scale questions and the scoring of "highly annoyed" are discussed. The revisions are designed to encourage further standardization in noise annoyance research. The paper highlights research needs that, if addressed, would strengthen the methodology underlying the assessment of noise annoyance including multidimensional assessments of annoyance.

Recent World Health Organization regulatory recommendations are not supported by existing evidence.

The European Region of the World Health Organization (WHO) recently published revised recommendations for transportation noise exposure intended to limit adverse health effects. WHO's newly recommended "safe" limit for aircraft noise exposure is about an order of magnitude lower than the limits currently adopted by most European countries. WHO defines "safe exposure" as the level corresponding to an annoyance prevalence rate of 10% highly annoyed. The revised recommendations are based on a limited selection of post-2000 publications. About half of the cited studies rely on nonstandard questionnaires, respondent selection, and definitions of annoyance prevalence rates which over-estimate annoyance. A re-analysis of a larger and more representative selection of studies that relies on standard procedures shows that no meaningful changes in prevalence rates of high annoyance with aircraft noise have occurred and that existing evidence does not support WHO's revised recommendations.

On the Temporal Stability of People's Annoyance with Road Traffic Noise.

Sixty-one social surveys on annoyance caused by road traffic noise conducted world-wide over a period of forty-five years have been re-analyzed by various means for possible temporal trends. Eighteen of these surveys were conducted after 2000. People's reactions to road traffic noise seem to have been stable across the study period. No indications were found that would warrant revision of the current EU reference curve for predicting the annoyance from road traffic noise.

Challenges of the Use of Sound Emergence for Setting Legal Noise Limits.

In the vast majority of legislation on environmental noise, the metric used for expressing limit values is based on sound pressure levels. But some countries have introduced sound emergence limit values where the compliance of a noise-generating activity is defined as a maximum allowable difference between the sound pressure level with and without the regulated activity operating. This paper investigates the foundations and the merits of this kind of differential noise limit values. Our review of literature indicates that there is very little evidence supporting the use of differential noise limits over absolute ones. Moreover, while sound emergence limits seem to originate from consideration about audibility of the regulated noise source, they appear to give little insight into what is audible and what is not. Furthermore, both the definition and the practical measurement of sound emergence raise several challenges that compromise reproducibility. In addition, first, the reference to background noise makes it very difficult first to ascertain the conformity of noisy installations in the long run, second to effectively protect the community from excessive noise and third to evaluate conformity on the basis of simulations. When switching to another metric is not an option the paper makes recommendations toward a more reliable use of sound emergence.

Sample size implications for calculations of community tolerance level values from social surveys of noise-induced annoyance.

The relationship between noise exposure and the prevalence of annoyance of transportation noise in a community is commonly characterized by a so-called dose-response curve, also referred to as exposure-response curves. Such curves are generally estimated by meta-analyses of social survey findings. Large numbers of survey respondents are generally assumed to be associated with exposure-response relationships of high accuracy and precision. The community tolerance level (CTL) approach [Fidell, Mestre, Schomer, Berry, Gjestland, Vallet, and Reid (2011). J. Acoust. Soc. Am 130, 791-806] to analysis of noise-induced annoyance in communities assumes (1) that the prevalence of a consequential degree of annoyance in communities grows as does the duration-adjusted loudness of noise exposure, and (2) that this rate-of-growth function is constant for all transportation noise sources. Because CTL analysis assumes a growth function with a single parameter the entire relationship between noise exposure and prevalence of high annoyance can be described by a single quantity-a CTL value. A re-analysis of the results of about 100 social surveys shows that a sample of about 300 respondents yields results with useful precision limits for regulatory purposes.

Reply to Guski, Schreckenberg, Schuemer, Brink and Stansfeld: Comment on Gjestland, T. A Systematic Review of the Basis for WHO's New Recommendation for Limiting Aircraft Noise Annoyance. Int. J. Env. Res. Pub. Health 2018, 15, 2717.

The European Regional Office of the World Health Organization (WHO, 2018) recently dramatically lowered its former (WHO, 2000) recommendations for cumulative aircraft noise exposure levels associated with risks of adverse public health effects. WHO's recommendations, although lacking the force of law, are nonetheless of interest to aviation regulatory bodies and to the public at large. It is therefore important that WHO's recent recommendations receive and withstand careful scrutiny. WHO's (2018) recommendations are based on controversial assumptions, analyses and interpretations prepared by Guski et al. (2017). Gjestland (2018) identified a number of limitations of the opinions expressed by Guski et al. (2017). Guski et al. (2019) subsequently challenged some of Gjestland's (2018) observations. This paper responds to the defenses offered by Guski et al. (2019) of the opinions expressed in their prior (2017) publication.

A Systematic Review of the Basis for WHO's New Recommendation for Limiting Aircraft Noise Annoyance.

The new WHO Environmental Noise Guidelines for the European Region have recommendations for limiting noise exposure associated with adverse health effects. The limits are said to be based on a systematic review of existing evidence. This paper gives a systematic assessment of the presented evidence with respect to annoyance from aircraft noise. The new guidelines have been based on the results from a selection of existing aircraft noise studies. This paper demonstrates that a similar selection of other existing post-2000 studies will yield very different results. In addition, the validity of the presented evidence has been questioned as some of the referenced studies have not been conducted according to standardized methods, and the selection of respondents is not representative of the general airport population.

Annoyance survey by means of social media.

Social surveys have been the conventional means of evaluating the annoyance caused by transportation noise. Sampling and interviewing by telephone, mail, or in person are often costly and time consuming, however. Data collection by web-based survey methods are less costly and may be completed more quickly, and hence, could be conducted in countries with fewer resources. Such methods, however, raise issues about the generalizability and comparability of findings. These issues were investigated in a study of the annoyance of aircraft noise exposure around Brazil's Guarulhos Airport. The findings of 547 interviews obtained with the aid of Facebook advertisements and web-based forms were analysed with respect to estimated aircraft noise exposure levels at respondents' residences. The results were analysed to assess whether and how web-based surveys might yield generalizable noise dose-response relationships.

The efficacy of sound regulations on the listening levels of pop concerts.

This analysis of new and previously collected data was done to validate the efficacy of recommendations for limits regarding sound exposure levels at live pop concerts. After the World Health Organization (WHO) recommended limiting the sound levels at such concerts to avoid noise induced hearing damage among the audience, the actual levels at concerts where these recommendations are observed, have stabilized around 100 dBA. This is a level that is considered acceptable by WHO. At concerts where there are no limitations, however, the sound levels in the audience area are still increasing far beyond safe limits and thus the exposure may represent a serious threat to people's hearing.

How to measure community tolerance levels for noise.

Relationships between noise exposure and transportation noise induced annoyance have been studied extensively for several decades. The annoyance due to aircraft noise exposure is in the present paper assumed to be influenced by the day-night yearly average sound level (DNL). It has long been recognized that the annoyance also depends on non-DNL factors, but this is complicated-resulting in a variety of different modeling strategies. Motivated by this, the community tolerance level (CTL) was introduced in 2011 for a loudness-based psychometric function. It is a single parameter that accounts for the aggregate influence of other factors. This paper suggests and investigates different methods for the measurement of the CTL. The methods are illustrated on data found in the literature, on recent surveys around two Norwegian airports, and on simulated data. The results from the presented methods differ significantly. An elementary method is shown to give a measurement of the CTL with smaller uncertainty, and is recommended as a replacement for the originally suggested least-squares method. Methods for evaluating the measurement uncertainty are also presented.

Community response to noise in Vietnam: exposure-response relationships based on the community tolerance level.

Social surveys on noise annoyance have been conducted in five different cities in Vietnam. The surveys included both aircraft noise (three airports) and road traffic noise (five cities). The main objective for these studies was to establish dose-response functions that were representative for Vietnam. The results have been compared with results from similar surveys from other regions. Dose-response functions for aircraft noise in Vietnam showing the percentage of highly annoyed people versus the noise level are nearly identical to those presented in the European Noise Directive [European Commission (2002). http://ec.europa.eu/environment/noise/directive.htm]. For road traffic noise, however, the results indicate that people in Vietnam are more tolerant. The noise levels can be increased by 5-10 dB in order to have a response similar to the curve recommended by the European Commission.

Noise and exposure of personnel aboard vessels in the Royal Norwegian Navy.

Despite awareness of noise aboard vessels at sea, few studies have reported measured noise levels aboard ships. This study aimed to describe the noise levels aboard vessels in the Royal Norwegian Navy (RNoN), and to assess the noise exposure of personnel aboard RNoN vessels. In 2012/2013 noise measurements were conducted aboard 14 RNoN vessels from four different vessel classes (frigates, coastal corvettes, mine vessels, and coast guard vessels) which were included in this study. Mean and median A-weighted noise levels (L p,A) in decibel (dB(A)) were calculated for different locations in each vessel class. The noise exposure of RNoN personnel was assessed by dosimeter measurements, and with a task-based (TB) strategy. The TB strategy used means of area measured noise levels in locations and the personnel's mean reported time spent in the respective locations to estimate the exposure. Area measurements of noise during sailing with typical operating modes, showed that for all vessel classes the noise levels were high in engine rooms with median L p,A ranging from 86.4 to 105.3 dB(A). In all the other locations the vessel class with the highest noise levels (coastal corvettes) had a median L p,A ranging from 71.7 to 95.0 dB(A), while the vessel class with the lowest noise levels (coast guard vessels) had a median L p,A ranging from 41.5 to 57.8 dB(A). For all vessel classes the engineers and electricians had amongst the highest 24-hour noise exposure (L p,A,24h), both before and after adjusting for estimated use of hearing protective devices (L p,A,24h > 67.3 dB(A)). The vessel class with the highest personnel exposure levels (coastal corvettes) had L p,A,24h ranging from 76.6 to 79.3 dB(A). The vessel class with the lowest personnel exposure levels (coast guard vessels) had an L p,A,24h ranging from 47.4 to 67.3 dB(A). In general, the dosimeter measurements gave higher exposure levels than those estimated with the TB strategy. All vessel classes, except the coast guard vessels, had noise levels exceeding the RNoN standard's recommended maximum noise levels. The area measured noise levels and the personnel's exposure estimates indicate that navy personnel aboard RNoN vessels are at risk of acquiring adverse health effects from exposure to noise, and that a program to reduce the noise levels should be implemented.

Community response to noise.

Activities from 2008 to 2011 by ICBEN community response to noise team were summarized. That is, individual community-based indexes such as community tolerance Level, Zuricher Fluglarm Index (ZFI) and Frankfurter Fluglarm Index (FFI/FNI) were newly proposed, differences in railway bonus between Europe and Asia were discussed by a Swedish survey, socio-acoustic surveys were reported from developing countries, and annoyance equivalents and dominant source models were proposed as the adequate combined noise model. Furthermore, not only negative, but also positive aspects of sound were discussed as soundscape studies. Finally, seven items were listed as future team activities.

Role of community tolerance level (CTL) in predicting the prevalence of the annoyance of road and rail noise.

Fidell et al. [(2011), J. Acoust. Soc. Am. 130(2), 791-806] have shown (1) that the rate of growth of annoyance with noise exposure reported in attitudinal surveys of the annoyance of aircraft noise closely resembles the exponential rate of change of loudness with sound level, and (2) that the proportion of a community highly annoyed and the variability in annoyance prevalence rates in communities are well accounted for by a simple model with a single free parameter: a community tolerance level (abbreviated CTL, and represented symbolically in mathematical expressions as L(ct)), expressed in units of DNL. The current study applies the same modeling approach to predicting the prevalence of annoyance of road traffic and rail noise. The prevalence of noise-induced annoyance of all forms of transportation noise is well accounted for by a simple, loudness-like exponential function with community-specific offsets. The model fits all of the road traffic findings well, but the prevalence of annoyance due to rail noise is more accurately predicted separately for interviewing sites with and without high levels of vibration and/or rattle.

A first-principles model for estimating the prevalence of annoyance with aircraft noise exposure.

Numerous relationships between noise exposure and transportation noise-induced annoyance have been inferred by curve-fitting methods. The present paper develops a different approach. It derives a systematic relationship by applying an a priori, first-principles model to the findings of forty three studies of the annoyance of aviation noise. The rate of change of annoyance with day-night average sound level (DNL) due to aircraft noise exposure was found to closely resemble the rate of change of loudness with sound level. The agreement of model predictions with the findings of recent curve-fitting exercises (cf. Miedma and Vos, 1998) is noteworthy, considering that other analyses have relied on different analytic methods and disparate data sets. Even though annoyance prevalence rates within individual communities consistently grow in proportion to duration-adjusted loudness, variability in annoyance prevalence rates across communities remains great. The present analyses demonstrate that 1) community-specific differences in annoyance prevalence rates can be plausibly attributed to the joint effect of acoustic and non-DNL related factors and (2) a simple model can account for the aggregate influences of non-DNL related factors on annoyance prevalence rates in different communities in terms of a single parameter expressed in DNL units-a "community tolerance level."

The socio-economic impact of noise: a method for assessing noise annoyance.

Norwegian authorities have developed and adopted a method for assessing the magnitude of noise impact on a community in quantitative terms. The method takes into account all levels of noise annoyance experienced by all the residents in an area and transforms these data into a single quantity that can also be expressed in monetary terms. This method is contrary to other commonly used assessment methods where only a certain fraction of the impacted people, e.g. those "highly annoyed," is considered.