The impact of environmental noise on drivers' cognitive abilities: A case study on in-vehicle voice interaction interfaces

To investigate the impact of environmental noise on the cognitive abilities of drivers, this study, using in-vehicle voice interaction as an example, conducted laboratory experiments to assess the effects of road traffic noise, entertainment noise, and white noise stimuli on drivers' attention and short-term memory. The noise levels simulated to mimic acoustic conditions during car driving ranged from 35 dB(A) to 65 dB(A). The conclusions drawn were as follows: (1) Noise levels directly influenced subjective annoyance levels, with annoyance linearly increasing as noise levels escalated; (2) Both attention and short-term memory task reaction times of drivers were significantly influenced by noise types. Compared to traffic noise and white noise, drivers' cognitive efficiency was lower under entertainment noise. (3) Performance in complex cognitive tasks was more susceptible to noise levels compared to simple cognitive tasks; (4) Experimentally, it was found that drivers exhibited the highest cognitive efficiency in cognitive tasks when the environmental noise level was 55 dB(A), as opposed to noise levels of 35 dB(A), 45 dB(A), and 65 dB(A).

Soundscape of an eastern coastal city of India

The soundscape study of an eastern Indian coastal city (Puri) has been investigated. Acoustic data were collected at 36 sampling locations during two time intervals in and around Puri. A number of noise indices, namely, Lmin, Lmax, and Leq, were calculated to demonstrate the noise level of this city. Noise maps are generated using ARC-GIS to investigate the impact of road traffic noise on the soundscape of the city. The response of the public was appraised by a questionnaire. Due to variable traffic features, the equivalent noise level (Leq) as well as peak (L10) and background noise (L90) levels varied with location and time of the day. It was found that socio-demographic characteristics have no bearing on the amount of annoyance. However, a link was observed between age, hearing condition, and noise perception, as well as between gender and impacts of noise.

Statistical and spatio-temporal analyses of noise pollution level and its health impact

Due to rapid urbanization and exponential growth in transportation; traffic noise has become a major area of concern. Noise not only disturbs our day-to-day life but also have severe adverse health effects over humans which further may lead to mortality. This paper focuses on the behavior of noise levels of Lucknow city over a decade and establishes its correlation with impact on human health in terms of annoyance and sleep disturbance. Apart from L_eq, different noise parameters like L₁₀, L₅₀, L₉₀, Traffic Noise Index (TNI), Noise Pollution Index (NPI), and Noise Climate (NC) have also been analyzed to understand the variation of noise. At all the locations, the noise level has been found exceeding their prescribed standards during day time and night time except at Amausi. Out of nine locations, TNI was found to be exceeding at three locations during day time and NPI exceeding at one location. However, during night time both values of TNI and NPL were observed within the limit at all the locations. From the noise map of the city during day time and night time, among all sampling locations, Charbagh has been found to be worst affected by noise pollution. A strong positive correlation has been observed among the total population, vehicular count, and day and night time noise data, which directly contribute to a higher percentage of sleep disturbance and annoyance among residents. Due to the increase in noise levels over a period of time, almost four times the population get affected by high annoyance and almost double the population get affected by sleep disturbance.

Health impact assessment of road traffic noise exposure based on different densification scenarios in Malmö, Sweden

While urbanization provides many opportunities to those arriving in thriving urban areas, a greater number of residents necessitates the expansion of housing and infrastructure. This is often achieved through densification, which can lead to increased noise, particularly through increased road traffic. A key challenge of promoting healthy urban planning is to understand potential health effects, especially on the local level. The aim of the present study is, therefore, to estimate and compare the health impacts of road traffic noise exposure for various urban densification scenarios within a neighborhood (Lorensborg) in Malmö, Sweden. The three scenarios include 1) Present-day, representing the study area as it is presently organized; 2) Planned municipal strategy (the city of Malmö's own densification plans) and 3) Health-centred, which involves major structural alterations and reflects an effort prioritize a health-centred approach. Noise was modelled using the Nordic prediction method for road traffic. Health outcomes included noise annoyance, adverse sleep disturbance, ischemic heart disease (IHD) incidence and mortality. Within all scenarios, a large proportion of the study population was exposed above the WHO's health-based guideline value (L_den 53 dB): >80% for Present-day and Planned municipal strategy scenarios, and almost 50% in the Health-centred scenario. Still, densifying Lorensborg (population ≈9,600) according to the Health-centred scenario could prevent 549 cases of highly annoyed, 193 cases of adverse sleep disturbance, 4.7 new cases of IHD (8.9% of total cases), and 1.5 deaths due to IHD (17.8% of IHD mortality) annually. The results demonstrated that it is possible to considerably lower the health impact with a more health-centred densification strategy. Important co-benefits for public and environmental health include air pollution reduction and green space creation, although their health effects were not quantified in the present study. Urban planning initiatives must be more ambitious in order to create healthy, sustainable cities.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Parameters influencing population annoyance pertaining to air pollution

Annoyance caused by particulate matter qualifies as a public health problem, as it can be seen as an ambient stressor causing stress, diseases and affecting the quality of life. Previous studies have shown a complex relationship between annoyance and perception of air pollution, health problems occurrences, air pollutants concentration levels and location within the urban area, which should be better investigated. The objective of this work is to identify the parameters that influences perceived annoyance caused by air pollution. Additionally, we propose the analyses of exposure-response relationship between perceived annoyance and concentration levels of particulate matter (TSP and PM₁₀). Questionnaire-based surveys were conducted in sub regions around of the air quality monitoring stations in metropolitan area of Vitoria, Brazil. Logistic regression was used to identify the associations between qualitative questionnaire variables and air pollution expressed by PM concentrations. Results have shown that 90% of the population reports nuisance by air pollution and about 80% of respondents frequently perceived air pollution by dust. The determinants parameters and subjective factors related to particles annoyance perception can be used in order to predict air pollution impact on the studied region population. By exposure-response relationship when the concentration level of PM increases, the probability of being annoyed also grows. The results and the methodology discussed here can be very useful for planning purposes where the stakeholders usually do not have access to detailed information, especially for micro-management in a regional or city-planning level.

Environmental noise-induced cardiovascular, metabolic and mental health disorders: a brief review

BACKGROUND

Environmental noise is a pervasive pollutant that is one of the greatest environmental threats to mental, physiological and psychological well-being and has a significant global health burden associated with it. Many epidemiological studies indicate long-term relationship of noise pollution with wide range of metabolic, cardio-vascular and respiratory disorders and diseases.

OBJECTIVE

The goal of this study was to thoroughly analyse available literature on public health implications and various underlying biological mechanisms associated with ambient noise exposure, taking into account both objective and subjective measures of noise exposure.

METHODS

A search of literature for review on environmental noise and associated cardiovascular, mental health and metabolic implications on human health was done using Web of Science, Google Scholar and PubMed databases.

DISCUSSION

Experimental studies indicate that noise exposure leads to endocrine effects, increased incidence of diabetes, impairment of cognitive performance, sleep disturbance and annoyance. Epidemiological evidence indicates that high levels of noise, particularly at night, may cause arterial hypertension and endothelial dysfunction due to higher level of stress hormones and oxidative stress. An increased incidence of cardio-vascular diseases like myocardial infarction, heart rate, ischemic heart disease, stroke and heart failure is associated with noise-induced mental stress. Furthermore, psychological and mental health issues like anxiety and depression are also related with exposure to noise pollution.

CONCLUSION

This article summarises a comprehensive and systematic knowledge established in recent noise research with the spotlight on cardiovascular, metabolic and mental health disorders of environmental noise, providing unique understanding into underlying mechanisms.

A Bayesian network model to predict the role of hospital noise, annoyance, and sensitivity in quality of patient care

Background

Hospital noise can adversely impact nurses’ health, their cognitive function and emotion and in turn, influence the quality of patient care and patient safety. Thus, the aim of this study was to predict the contributing roles of exposure to hospital noise, staff noise-sensitivity and annoyance, on the quality of patient care.

Methods

This descriptive and cross-sectional study was carried out among nurses in an Iranian hospital. To determine nurses’ noise exposure level, the noise was measured in 1510 locations across the hospital in accordance with ISO 9612 standards using KIMO DB 300/2 sound level meter and analyzer. An online survey was used to collect nurses’ individual data. Study questionnaires included demographics, Weinstein noise sensitivity scale, noise annoyance scale, and quality of patient care scale. Finally, to analyze the data, Bayesian Networks (BNs), as probabilistic and graphical models, were used.

Results

For the high noise exposure state, high noise sensitivity, and high annoyance, with the probability of 100%, the probability of delivering a desirable quality of patient care decreased by 21, 14, and 23%, respectively. Moreover, at the concurrently high noise exposure and high noise sensitivity with the probability of 100%, the desirable quality of patient care decreased by 26%. The Bayesian most influence value was related to the association of noise exposure and annoyance (0.636). Moreover, annoyance had the highest association with the physical aspect of quality of care (0.400) and sensitivity had the greatest association with the communication aspect (0.283).

Conclusion

Annoyance induced from environmental noise and personal sensitivity affected the quality of patient care adversely. Moreover, noise and sensitivity had a separate direct adverse effect upon the quality of patient care, and their co-occurrence reduced the potential for delivering quality patient care.

Noise as a cause of neurodegenerative disorders: molecular and cellular mechanisms

Noise as an environmental stressor becomes of increasing importance in our industrialized world, and especially traffic noise from the environment represents a potential novel neurodegenerative risk factor, as well as for hearing loss. A significant number of studies have been suggested that the overproduction of reactive oxygen species (ROS) has a complex role in stimulation of pathologic events. Experimental studies upon molecular pathways of traffic noise exposure proposed that it increased the level of stress hormones and mediated the inflammatory and oxidative stress (OS) pathways resulting in endothelial and neuronal dysfunction. Studies have shown that neurons are especially sensitive to OS due to high polyunsaturated fatty acids content in membranes, high oxygen uptake, and weak antioxidant defense. However, OS induces the necrotic and apoptotic cell deaths in the cochlea. Chronic noise is one of the many overall reasons of obtained sensorineural hearing loss which destroys cognitive functions in human and animals, as well as suppresses neurogenesis in the hippocampus. Nevertheless, behavioral disorders caused by noise are mainly accompanied with oxidative stress, but the clear molecular mechanism of neurodegeneration due to disruption of the pro- and antioxidant systems is still not fully understood. This paper aims to highlight the down-stream pathophysiology of noise-induced mental disorders, including hearing loss, annoyance, anxiety, depression, memory loss, and Alzheimer's disease, describing the underlying mechanisms of induction of inflammation and oxidative stress.

Impact of COVID-19 pandemic on aircraft noise levels, annoyance, and health effects in an urban area in Oman

This study aimed at investigating aircraft noise exposure levels, their annoyance, and potential health effects among communities living within airport catchment areas during the COVID-19 pandemic. Both field measurements and an online survey approach were used to investigate aircraft noise exposure levels, annoyance, and general health effects among residents living near Muscat International Airport (MCT) in Muscat, Oman, amid the COVID-19 period. The study found a drastic decline in aircraft noise levels due to the introduction of COVID-19 intervention measures such as lockdowns, social distancing, and closure of airports. In June 2020, during the COVID-19 pandemic, average daily aircraft noise levels of LAeq (39.9 dB(A)) and Lmax (49.7 dB(A)) was observed compared to the previous year (April-May 2019) of 58.5 and 76.8 dB(A), indicating aircraft noise reductions level of 32% and 35%, respectively. The results of the online social survey among 187 participants showed that most (58.8%) of the respondents did not feel that the level of noise produced by aircraft causes annoyance. During the day, the vast majority of the interviewees did not complain of any annoyance during the morning (45.5%), afternoon (39.6%), and evening (31%) with only < 4% of residents have reported a very high degree of annoyance of during COVID-19 pandemic period. Very few people (17%) did complain of experiencing general health problems while 29% did not know of any potential health effects that could be attributed to aircraft noise exposures. Aircraft noise annoyance complaints among the As-Seeb residents during the pre-COVID-19 pandemic periods were reported to be extremely high reaching about 84% compared to 41% during this current COVID-19 pandemic period. These findings support the need to develop future sustainable noise mitigation policies in order to help reduce noise exposures and improve human health during post-COVID-19 pandemic periods.

Impact of road traffic noise on annoyance and preventable mortality in European cities: A health impact assessment

BACKGROUND

Road traffic is the main source of environmental noise in European cities and one of the main environmental risks to health and wellbeing. In this study we aimed to provide an in-depth assessment of available road traffic noise data and to estimate population exposure and health impacts for cities in Europe.

METHODS

We conducted the analysis for 724 cities and 25 greater cities in 25 European countries. We retrieved road traffic strategic noise maps delivered under the Environmental Noise Directive (END) or available from local sources. We assessed noise exposure using the 24 h day-evening-night noise level indicator (L_den) starting at exposure levels of 55 dB L_den - based on data availability - for the adult population aged 20 and over (n = 123,966,346). For the adults exposed to noise levels above 55 dB L_den we estimated the health impacts of compliance with the World Health Organization (WHO) recommendation of 53 dB L_den. Two primary health outcomes were assessed: high noise annoyance and Ischemic Heart Disease (IHD), using mortality from IHD causes as indicator. Exposure Response Functions (ERFs) relating road traffic noise exposure to annoyance and IHD mortality were retrieved from the literature. Uncertainties in input parameters were propagated using Monte Carlo simulations to obtain point estimates and empirical 95% Confidence Intervals (CIs). Lastly, the noise maps were categorized as high, moderate and low quality following a qualitative approach.

RESULTS

Strategic noise map data was delivered in three distinct formats (i.e. raster, polygon or polyline) and had distinct noise ranges and levels of categorization. The majority of noise maps (i.e. 83.2%) were considered of moderate or low quality. Based on the data provided, almost 60 million adults were exposed to road traffic noise levels above 55 dB L_den, equating to a median of 42% (Interquartile Range (IQR): 31.8-64.8) of the adult population across the analysed cities. We estimated that approximately 11 million adults were highly annoyed by road traffic noise and that 3608 deaths from IHD (95% CI: 843-6266) could be prevented annually with compliance of the WHO recommendation. The proportion of highly annoyed adults by city had a median value of 7.6% (IQR: 5.6-11.8) across the analysed cities, while the number preventable deaths had a median of 2.2 deaths per 100,000 population (IQR: 1.4-3.1).

CONCLUSIONS

Based on the provided strategic noise maps a considerable number of adults in European cities are exposed to road traffic noise levels harmful for health. Efforts to standardize the strategic noise maps and to increase noise and disease data availability at the city level are needed. These would allow for a more accurate and comprehensive assessment of the health impacts and further help local governments to address the adverse health effects of road traffic noise.

Effect of ambient noise on indoor environments in a health care facility in Oman

Hospital-noise levels can induce physiological responses and affect sleep quality, which could contribute to cardiovascular-related health problems. Till date, high-resolution hospital noise exposure assessment studies have not received much attention in Oman. This study aims at assessing sound pressure levels across hospital wards and intensive care unit (ICU) rooms to determine annoyance and potential health effects based on perception and risk estimates. An indoor exposure assessment using high precision noise sensors was conducted in a female medical ward (FMW), isolated ward (SLW), emergency ward (EMW), and intensive care unit (ICU) in a public hospital in Muscat city, Oman. Self-administered questionnaire was randomly distributed among respondents using both online and field survey approach to ascertain annoyance, health effects, and potential risks associated with exposure. The study found that 24-h noise levels (L_Aeq) ranged from 55.2 to 61.7 dB(A) in the hospital wards and ICU rooms, which exceeded WHO's hospital indoor rooms critical limit of 35 dB(A) by 58-76%. A total of 150 participants took part in the survey. Among the respondents, 53% reported moderate annoyance at the hospital wards, while 56% felt sensitivity to the noise levels. Noise annoyance was reported by the majority of the patients across the various wards and emergency rooms as causing slight annoyance (50%) and intermittent sleep disturbances (49%). The majority (73%) of the medical staff have complained that the current noise levels affect overall work performance (p = 0.004), while 70% of them have further complained of it as a cause of workplace distraction (p = 0.011). Logistic binary regression analysis has revealed that the complaint of noise sensitivity has a positive association with noise levels in VCW (OR: 1.54; 95% CI: 0.92-2.58), and reported loss of concentration by the medical staff also associated with noise levels at the EMW (OR: 1.61; 95% CI: 0.65-4.01). Quantitative risk estimates showed that both the percentages of highly annoyed (HA) persons (16%), and highly sleep-disturbed (HSD) persons (9%) were very high in FMW, while ICU was found to have the lowest risk. However, the greater number of the respondents (87%) believed that there are possibilities of mitigating (p < 0.001) the current noise levels.

What is Noise Sensitivity?

Background

Noise sensitivity moderates the association between environmental noise exposure and annoyance and health outcomes.

Methods

In normally hearing adults, we measured noise sensitivity in three ways: using the noise sensitivity questionnaire, a 3-point self-rating, and the loudness discomfort level (LDL; mean reported discomfort level for tone bursts). We then presented recordings of a 15-second 80 dBLAeq aeroplane overflight and participants rated the annoyance and loudness they experienced.

Results

The three measures of noise sensitivity were not well correlated with each other, and only the overall LDL was associated with the ratings of loudness and annoyance in response to the aeroplane sounds.

Conclusions

This implies that our current measures of noise sensitivity may only capture parts of the underlying construct, and therefore underestimate effects due to it on the association between environmental noise and annoyance and health outcomes. We developed a theoretical model to describe the set of factors that may influence a person's sensitivity to noise and propose that interaction between the systems described is the basis for noise sensitivity. This paradigm alters the focus of noise research from the annoyance caused by the sound, to the sensitization to noise that may occur as a result of the interplay of many factors. We hope that our model will allow research to explore the sensitizing factors for noise more easily and systematically.

Noise annoyance and vibration perception assessment on passengers during train operation in Guangzhou Metro

With the development of urban rail transit, taking the metro train has become one of the main modes of transportation, and passengers have an increasing demand for the comfort of taking the metro trains. This paper mainly discusses the impact of noise and vibration caused by metro train on passengers. All 13 metro lines in Guangzhou, China, were selected to conduct the questionnaire survey on the subjective perception of 601 respondents. At the same time, noise and vibration measurements were carried out in the train. The results show that the distribution of noise and vibrations along the metro lines is not uniform, and 50.6% of the interviewees are disturbed by noise. Wheel-rail squeal was found to be the most annoying and disturbing noise source. Three dose-response relationships for noise, vertical vibration, and horizontal vibration are proposed, respectively. The proposed dose-response relationship can be applied to the evaluation of noise annoyance or vibration perception in an environment similar to metro lines. Once the noise or vibration level of a metro line is obtained, the noise disturbance or vibration perception can be estimated. As for the dose-response relationship of vibration perception, people's sensitivity to vibration is much lower than that to noise. Horizontal vibrations are more acceptable to passengers, while vertical vibrations are more disturbing to passengers. The results are helpful to predict the noise annoyance and vibration perception of train passengers between metro stations, and to achieve the purpose of designing effective noise and vibration reduction measures.

A study on the assessment of traffic noise induced annoyance and awareness levels about the potential health effects among residents living around a noise-sensitive area

The present cross-sectional study aimed to evaluate the risk factors for traffic noise-induced annoyance and also assess the awareness levels among the exposed population concerning the health impacts caused by traffic noise. Field measurements were made to validate the application of the standard noise models, which were later used to present the acoustical environment and assess the exposure level around a super-speciality hospital surrounded by a residential zone. Results from the noise maps and façade maps revealed that the area was exposed to noise levels exceeding the upper safe limits by more than 10 dB(A). The effect of exposure in the form of annoyance and the awareness level were evaluated using a questionnaire survey in a sample of 565 residents. Attention questions were incorporated in the questionnaire, and the awareness level was evaluated using the mean awareness index score. Respondents living in noisy areas were having a higher risk for annoyance as compared to those living in quiet areas (OR = 4.06; 95% CI = 2.79-5.88). Reporting poor sleep quality, being sensitive to noise, and noise perception at home were the significant risk factors for annoyance. Most of the respondents were classified as having no/little awareness about serious health ailments caused by traffic noise. Lower awareness levels, despite a higher literacy rate and a higher percentage of the young population, imply that there is a need for undertaking mass awareness programmes so that the impacts can be reduced to a minimum, if not eliminated.

Evaluating annoyance mitigation in the screening of train-induced noise and ground vibrations using a single-leaf traffic barrier

External sources such as traffic and construction work cause noise and vibration in nearby buildings, potentially annoying human residents. Today, almost every fifth European is harmfully affected by traffic noise and vibration. Wave barriers placed on or embedded within the soil between the source and the receiver can mitigate the transmission of ground vibration, and the airborne noise transmission can be reduced in a similar manner with a screen acting as a noise barrier. As a novel approach, the present work explores the efficiency of combining ground vibration and noise barriers into one. To this end, numerical experiments were performed by a semi-analytic finite-element method for ground vibration and the boundary-element method for sound propagation. This involved time-harmonic analyses carried out in order to study the performance of various configurations of barriers focusing on vertical barriers rigidly attached to the ground surface or embedded into the soil. Parametric analyses were conducted on the achieved vibration and noise mitigation with different types of ground-vibration barriers and noise barriers, respectively. The combined effect of the noise and ground vibration barriers were then assessed to investigate their potential for possibly reducing the negative impact on lineside residents. The aim of this work, though, is to highlight a metric, recently developed, which reports the probability on the number of residents who could be annoyed by intrusive railway noise and vibration. It is shown that a single structural-element can target a combined reduction of around 15% probability in annoyance to vibration levels combined with a 12 dB insertion loss which amounts to a 30% reduction in probability of annoyance due to railway traffic intrusive noise.

Effects of Tonal Noise on Workers' Annoyance and Performance

Objective

Numerous references indicate that the subjectively assessed tonal noise annoyance is higher than that of broadband noise. There are no criteria for the impact of tonal noise in assessing the occupational environment for both indoor areas and workplaces.

Materials and Methods

The study participants included 50 people who met the audiometric qualification criteria. The research method employed both a questionnaire survey and computer psychological tests checking work performance, attention level, and memory. Four types of generated test signals were developed (filtered noise - A and three signals with tonal components 125, 1600, and 8000 Hz - B, C, and D) at the same sound level A of 55 dB. Test signals C and D were assessed as causing the greatest annoyance and as the loudest.

Results

The results of some tests and the assessment of annoyance and of the volume of test signals containing medium and high frequency tonal components were correlated with the participants' noise sensitivity, determined on the basis of a questionnaire. Although there are no statistically significant differences, it was observed in most cases for signals with C (1600 Hz) and D (8000 Hz) tonal components that the results (mean values or median values) of psychological tests deteriorated with respect to a noise signal without tonal components (A) - a smaller number of calculations, a smaller number of correct responses, more errors made.

Conclusion

These results, combined with those of the questionnaire survey, justify the introduction of the tonality annoyance criterion for workstations where, among other things, focusing one's attention is required.

Assessment of noise levels and induced annoyance in nearby residential areas of an airport region in Oman

There is adequate evidence from epidemiological studies showing an association between noise exposures and incidence of cardiovascular diseases and cognitive impairment among exposed populations. This study aimed to investigate noise exposure levels in an airport region and their effects on the nearby two neighborhood communities (i.e., Al Seeb and Bawshar). To achieve this, noise levels were measured across 15 different points within the communities for more than 3 weeks at a median distance of 3.5 km from the airport runways using a sound level analyzer. In addition, we conducted an online social survey in a random sampling of a total of 913 residents who were living closer to the airport. A combination of a 5-point scale and 3-point Likert scale was used to assess the resident population's noise annoyance and the potential health impacts. The results revealed that the majority of the measured points have noise levels (55.71-65.24 L_Aeq dBA) exceeding both Oman and WHO critical limits. There was a general decrease in noise levels at points further away from the runways; thus, at points 2.5, 4.8, and 8.8 km, sound pressure levels were found to be 63.08, 57.41, and 52.31 dBA, respectively. However, steady noise levels were observed throughout most of the daily (24 h) measurements indicating continual exposures. Overall, 44.6% of residents reported noise annoyance level as very high, with Al Seeb inhabitants (46%) eliciting a greater percentage of annoyance levels compared to Bawshar (5%) due to their closer proximity to the airport. Also, the noise was significantly (p ˂ 0.001) associated with sleep disturbance, insomnia, irritation, and frightening. The majority of the residents complained of an increase in insomnia (41.5%), stress (34.3%), headache (47.3%), and cardiovascular diseases (16.2%). With the question of reducing noise exposures, about 41% of the respondents have plans of relocating to distant areas with low noise levels.

Association of Noise Annoyance with Measured Renal Hemodynamic Changes

BACKGROUND

Chronic mental stress is recognized as a modifiable risk factor for cardiovascular disease. The aim of this study was to demonstrate that noise annoyance-induced stress is associated with changes in renal hemodynamics.

METHODS

Renal hemodynamic parameters were measured using steady-state input clearance with infusion of para-aminohippuric acid and inulin in individuals with normal, high normal, and elevated blood pressure. All individuals ranked subjective annoyance due to noise in everyday life on a 7-grade Likert scale. The median of all rankings was used as a cutoff point to divide the group into noise-annoyed and non-noise-annoyed individuals. Different renal hemodynamic parameters were calculated based on the Gomez equation.

RESULTS

Noise-annoyed individuals (n = 58) showed lower renal plasma flow (599 ± 106 vs. 663 ± 124 mL/min, p = 0.009), lower renal blood flow (1,068 ± 203 vs. 1,172 ± 225 mL/min, p = 0.047), higher filtration fraction (22.7 ± 3.3 vs. 21.3 ± 3.0, p = 0.012), higher renal vascular resistance (88.9 ± 25.6 vs. 75.8 ± 22.9 mm Hg/[mL/min], p = 0.002), and higher resistance of afferent arteriole (2,439.5 ± 1,253.4 vs. 1,849.9 ± 1,242.0 dyn s-1 cm-5, p = 0.001) compared to non-noise-annoyed individuals (n = 55). There was no difference in measured glomerular filtration rate (133 ± 11.8 vs. 138 ± 15 mL/min, p = 0.181), resistance of efferent arteriole (2,419.4 ± 472.2 vs. 2,245.8 ± 370.3 dyn s-1 cm-5, p = 0.060), and intraglomerular pressure (64.0 ± 3.1 vs. 64.6 ± 3.5 mm Hg, p = 0.298) between the groups. After adjusting for age, renal plasma flow, renal blood flow, and renal vascular resistance remained significantly different between the groups, with a trend in increased afferent arteriolar resistance and filtration fraction.

CONCLUSION

In this study, noise annoyance was associated with reduced renal perfusion attributed to increased renal vascular resistance predominantly at the afferent site. Long-term consequences of this renal hemodynamic pattern due to noise annoyance need to be investigated.

Social inequality, noise pollution, and quality of life of slum dwellers in Pokhara, Nepal

This work is a cross-sectional comparative study conducted on 528 residents in the slum and non-slum areas of Pokhara, Nepal. Of the total number of respondents, 90.2% in the slums and 63.3% in the non-slums indicated the existence of a main source of noise, and 80.7% in the slums and 66.0% in the non-slums replied that they had been highly annoyed by noise. The indoor noise levels measured for 24 h were higher in slums than in non-slums, ranging from 59 to 78 dBA and from 51 to 69 dBA, respectively. The Mann-Whitney U test showed a significantly poorer status of slum dwellers in four health domains. Logistic regression analysis identified that living in a slum was a significant predictor (OR, 2.35; 95% CI, 1.35-4.09) of a low level of health. Meanwhile, a high level of noise annoyance was a good determinant (OR, 6.71; 95% CI, 3.13-14.36) of low quality of life among slum dwellers revealing a distinguishing negative effect of the high level of noise annoyance in the slum areas.

Estimating the health benefits associated with a speed limit reduction to thirty kilometres per hour: A health impact assessment of noise and road traffic crashes for the Swiss city of Lausanne

Reductions of speed limits for road traffic are effective in reducing casualties, and are also increasingly promoted as an effective way to reduce noise exposure. The aim of this study was to estimate the health benefits of the implementation of 30 km/h speed limits in the city of Lausanne (136'077 inhabitants) under different scenarios addressing exposure to noise and road crashes. The study followed a standard methodology for quantitative health impact assessments to derive the number of attributable cases in relation to relevant outcomes. We compared a reference scenario (without any 30 km/h speed limits) to the current situation with partial speed limits and additional scenarios with further implementation of 30 km/h speed limits, including a whole city scenario. Compared to the reference scenario, noise reduction due to the current speed limit situation was estimated to annually prevent 1 cardiovascular death, 72 hospital admissions from cardiovascular disease, 17 incident diabetes cases, 1'127 individuals being highly annoyed and 918 individuals reporting sleep disturbances from noise. Health benefits from a reduction in road traffic crashes were less pronounced (1 severe injury and 4 minor injuries). The whole city speed reduction scenario more than doubled the annual benefits, and was the only scenario that contributed to a reduction in mortality from road traffic crashes (one death per two years). Implementing 30 km/h speed limits in a city yields health benefits due to reduction in road traffic crashes and noise exposure. We found that the benefit from noise reduction was more relevant than safety benefits.

Incidence of depression in relation to transportation noise exposure and noise annoyance in the SAPALDIA study

Prospective evidence on the risk of depression in relation to transportation noise exposure and noise annoyance is limited and mixed. We aimed to investigate the associations of long-term exposure to source-specific transportation noise and noise annoyance with incidence of depression in the SAPALDIA (Swiss cohort study on air pollution and lung and heart diseases in adults) cohort. We investigated 4,581 SAPALDIA participants without depression in the year 2001/2002. Corresponding one-year mean road, railway and aircraft day-evening-night noise (Lden) was calculated at the most exposed façade of the participants' residential floors, and transportation noise annoyance was assessed on an 11-point scale. Incident cases of depression were identified in 2010/2011, and comprised participants reporting physician diagnosis, intake of antidepressant medication or having a short form-36 mental health score < 50. We used robust Poisson regressions to estimate the mutually adjusted relative risks (RR) and 95% confidence intervals (CI) of depression, independent of traffic-related air pollution and other potential confounders. Incidence of depression was 11 cases per 1,000 person-years. In single exposure models, we observed positive but in part, statistically non-significant associations (per 10 dB) of road traffic Lden [RR: 1.06 (0.93, 1.22)] and aircraft Lden [RR: 1.19 (0.93, 1.53)], and (per 1-point difference) of noise annoyance [RR: 1.05 (1.02, 1.08)] with depression risk. In multi-exposure model, noise annoyance effect remained unchanged, with weaker effects of road traffic Lden [(RR: 1.02 (0.89, 1.17)] and aircraft Lden [(RR: 1.17 (0.90, 1.50)]. However, there were statistically significant indirect effects of road traffic Lden [(β: 0.02 (0.01, 0.03)] and aircraft Lden [β: 0.01 (0.002, 0.02)] via noise annoyance. There were no associations with railway Lden in the single and multi-exposure models [(RR_{both models}: 0.88 (0.75, 1.03)]. We made similar findings among 2,885 non-movers, where the effect modification and cumulative risks were more distinct. Noise annoyance effect in non-movers was stronger among the insufficiently active (RR: 1.09; 95%CI: 1.02, 1.17; p_interaction = 0.07) and those with daytime sleepiness [RR: 1.07 (1.02, 1.12); p_interaction = 0.008]. Cumulative risks of Lden in non-movers showed additive tendencies for the linear cumulative risk [(RR_{per 10dB of combined sources}: 1.31 (0.90, 1.91)] and the categorical cumulative risk [(RR_{triple- vs. zero-source ≥45 dB}: 2.29 (1.02, 5.14)], and remained stable to noise annoyance. Transportation noise level and noise annoyance may jointly and independently influence the risk of depression. Combined long-term exposures to noise level seems to be most detrimental, largely acting via annoyance. The moderation of noise annoyance effect by daytime sleepiness and physical activity further contribute to clarifying the involved mechanisms. More evidence is needed to confirm these findings for effective public health control of depression and noise exposure burden.

Incidence of depression in relation to transportation noise exposure and noise annoyance in the SAPALDIA study

Prospective evidence on the risk of depression in relation to transportation noise exposure and noise annoyance is limited and mixed. We aimed to investigate the associations of long-term exposure to source-specific transportation noise and noise annoyance with incidence of depression in the SAPALDIA (Swiss cohort study on air pollution and lung and heart diseases in adults) cohort. We investigated 4,581 SAPALDIA participants without depression in the year 2001/2002. Corresponding one-year mean road, railway and aircraft day-evening-night noise (Lden) was calculated at the most exposed façade of the participants' residential floors, and transportation noise annoyance was assessed on an 11-point scale. Incident cases of depression were identified in 2010/2011, and comprised participants reporting physician diagnosis, intake of antidepressant medication or having a short form-36 mental health score < 50. We used robust Poisson regressions to estimate the mutually adjusted relative risks (RR) and 95% confidence intervals (CI) of depression, independent of traffic-related air pollution and other potential confounders. Incidence of depression was 11 cases per 1,000 person-years. In single exposure models, we observed positive but in part, statistically non-significant associations (per 10 dB) of road traffic Lden [RR: 1.06 (0.93, 1.22)] and aircraft Lden [RR: 1.19 (0.93, 1.53)], and (per 1-point difference) of noise annoyance [RR: 1.05 (1.02, 1.08)] with depression risk. In multi-exposure model, noise annoyance effect remained unchanged, with weaker effects of road traffic Lden [(RR: 1.02 (0.89, 1.17)] and aircraft Lden [(RR: 1.17 (0.90, 1.50)]. However, there were statistically significant indirect effects of road traffic Lden [(β: 0.02 (0.01, 0.03)] and aircraft Lden [β: 0.01 (0.002, 0.02)] via noise annoyance. There were no associations with railway Lden in the single and multi-exposure models [(RR_{both models}: 0.88 (0.75, 1.03)]. We made similar findings among 2,885 non-movers, where the effect modification and cumulative risks were more distinct. Noise annoyance effect in non-movers was stronger among the insufficiently active (RR: 1.09; 95%CI: 1.02, 1.17; p_interaction = 0.07) and those with daytime sleepiness [RR: 1.07 (1.02, 1.12); p_interaction = 0.008]. Cumulative risks of Lden in non-movers showed additive tendencies for the linear cumulative risk [(RR_{per 10dB of combined sources}: 1.31 (0.90, 1.91)] and the categorical cumulative risk [(RR_{triple- vs. zero-source ≥45 dB}: 2.29 (1.02, 5.14)], and remained stable to noise annoyance. Transportation noise level and noise annoyance may jointly and independently influence the risk of depression. Combined long-term exposures to noise level seems to be most detrimental, largely acting via annoyance. The moderation of noise annoyance effect by daytime sleepiness and physical activity further contribute to clarifying the involved mechanisms. More evidence is needed to confirm these findings for effective public health control of depression and noise exposure burden.

Exposure assessment to road traffic noise levels and health effects in an arid urban area

Road traffic noise exposures have been recognized as serious environmental health concerns, especially in most developing countries with arid climate conditions, rapid increase in vehicle population, and limited traffic management systems. The excessive noise exposure level is associated with increase in the incidence of cardiovascular diseases and anxiety, including annoyance. This study aimed at determining traffic noise levels in residential areas, including the assessment of its annoyance and health effects based on the people's perception and reportage. To do so, field measurement and traffic noise modeling were carried out in six road points to estimate the current noise levels along various roads close to human inhabitants in Muscat Governorate, Sultanate of Oman. The detailed measured noise levels in urban residential areas across the selected roads showed that noise levels have exceeded the local and international threshold limits at all locations during the entire day. The high sound levels (48.0-56.3 dBA) were observed using the US Federal Highway Administration's Traffic Noise Model (TNM, version 2.5) results, which were in agreement with the observed (56.3-60.4 dBA) data. To assess health implication to residents through interviews (n = 208), annoyance at home was found to be little (32%), moderate (28%), and high (9%) in comparison with workplace settings of 42%, 43%, and 15%, respectively. Nineteen percent of the interviewees had difficulties in sleeping, while 19.8% experienced stress due to road traffic noise exposures. Moreover, a strong association (p < 0.05) was established between the use and objection of noise barriers. The study revealed high noise levels and the prevalence of annoyance and health effects among the exposed population. Therefore, immediate action is required to tackle the current noise levels.

Effects of intensive care unit ambient sounds on healthcare professionals: results of an online survey and noise exposure in an experimental setting

BACKGROUND

Noise levels on intensive care units (ICUs) are typically elevated. While many studies reported negative effects of ICU ambient sounds on patients, only few investigated noise as a factor to influence well-being or performance in healthcare professionals.

METHODS

An online survey in the German-speaking part of Switzerland was conducted to assess how ICU soundscapes are subjectively perceived by healthcare professionals. The questionnaire was answered by 348 participants. Additionally, effects of noise on working memory performance were evaluated in an experimental noise exposure setting. Twenty-six healthcare professionals and 27 healthy controls performed a 2-back object-location task while being exposed to either ICU or pink noise.

RESULTS

Survey results demonstrate that a majority of participants was aware of heightened noise levels. Participants reported that mostly well-being, performance, and attention could be reduced, along with subjective annoyance and fatigue by ICU ambient sounds. Although no significant effects of noise exposure on working memory performance was observed, self-assessments revealed significantly higher stress levels, increased annoyance and distraction ratings as well as decreased confidence in performance after ICU-noise exposure.

CONCLUSION

Subjective assessments indicate that heightened noise levels on ICUs induce annoyance, with heightened stress levels, impaired well-being, and reduced performance being potential consequences. Empirical evidence with objective and physiological measures is warranted.

Are annoyance scores based on sound pressure levels suitable for snoring assessment in the home environment?

Purpose

An objective statement about the annoyance of snoring can be made with the Psychoacoustic Snore Score (PSS). The PSS was developed based on subjective assessments and is strongly influenced by observed sound pressure levels. Robustness against day-to-day interfering noises is a fundamental requirement for use at home. This study investigated whether or not the PSS is suitable for use in the home environment.

Methods

Thirty-six interfering noises, which commonly occur at night, were played in the acoustic laboratory in parallel with 5 snoring sounds. The interfering noises were each presented at sound pressure levels ranging from 25 to 55 dB(A), resulting in 3255 distinct recordings. Annoyance was then assessed using the PSS.

Results

In the case of minimally annoying snoring sounds, interfering noises with a sound pressure level of 25 dB(A) caused significant PSS changes from 40 to 55 dB(A) for annoying snoring sounds. If the interfering noise was another snoring sound, the PSS was more robust depending on the sound pressure level of the interfering noise up to 10 dB(A). Steady (no-peak) interfering noises influenced the PSS more strongly than peak noises.

Conclusions

The PSS is significantly distorted by quiet interfering noises. Its meaningfulness therefore depends strongly on the acoustic environment. It may therefore be assumed that scores dependent on sound pressure level are suitable for measurements when there is minimal ambient noise, as in the sleep laboratory. However, for measurements where noise is incalculable, as in the home environment, interfering noises may distort the results.

Snoring: is a reliable assessment possible?

Purpose

It is not easy to assess how severe and annoying a patient’s snoring is. Solid parameters are lacking; snorers cannot deliver a reliable self-assessment and it is uncertain whether bed partners’ statements can be relied upon. The purpose of the present study was therefore to investigate whether and how well snoring assessment based on acoustic parameters and bed partners’ reporting agree.

Methods

In a double-blind, placebo-controlled study on snoring treatment, several acoustic parameters [snoring index (SI), percentage snoring time (ST), sound pressure level, sound energy, loudness, psychoacoustic annoyance and psychoacoustic snore score (PSS)] were measured in 18 subjects during 24 polysomnographies. Bed partners also assessed snoring annoyance and loudness as well as treatment outcome.

Results

No correlation was found between the subjective annoyance caused by snoring and the acoustic parameters. Regarding perceived loudness, there was a moderate, significant correlation with loudness (N₅) and PSS over the hour with the highest SI. SI, ST, LAeq and maximum sound pressure level dB(A)_max showed no significant correlation. After the intervention only mean sound energy LAeq over the entire night showed a significant correlation (r_s = 0.782; p = 0.022) with bed partners’ assessments. However, this result was not confirmed in the second control night.

Conclusions

The non-existent or only weak correlation between bed partners’ ratings and objective parameters indicate that snoring severity should be evaluated with caution. Neither acoustic parameters, at least for one measurement over just one night, nor bed partners’ ratings should be used as the sole basis for snoring assessment.

Development and validation of Hyperacusis Handicap Questionnaire in individuals with tinnitus associated with hyperacusis

Introduction

Hypersensitivity to sound and tinnitus are often co-morbid and can influence emotional well-being, hearing, sleep, concentration, cause anxiety, and interfere with speech perception in noise.

Purpose

A clear measure of sensitivity to sound is important as there is dearth in standard protocol for evaluating hyperacusis in individuals with tinnitus. Although there are a few questionnaires to assess hyperacusis, a direct application of these questionnaires in the Indian context would be unfavorable.

Objectives

The study attempts to develop and validate an indigenous Hyperacusis Handicap Questionnaire (HHQ) for individuals with tinnitus associated with hyperacusis.

Method

A total of 25 questions were considered for validation. Further, 21 questions were subdivided into three sections of seven questions each, tapping, 'Functional,' 'Social,' and 'Emotional' aspects of the condition. It was administered on 77 individuals with tinnitus associated with hyperacusis in the age range of 20-55 years for further validation. A total score was obtained by adding all the three sub-scales.

Results

The internal consistency of the questionnaire was determined by Cronbach's Alpha (α) was α = 0.85; and, α = 0.83 for Functional, α = 0.81 for Social, α = 0.7 for Emotional subscales suggesting that the questionnaire can be used for the assessment of handicap associated with hyperacusis in individuals with tinnitus. Also, no significant difference in terms of gender and duration of tinnitus comparisons were seen.

Conclusions

The obtained results suggest that HHQ will aid in the characterization and quantification of the handicap associated with hyperacusis in individuals with tinnitus.

Assessment of noise pollution and its effects on human health in industrial hub of Pakistan

Faisalabad is one of the major industrial cities of Pakistan, which may cause noise pollution to the local residents due to the development of robust industrial and transport systems. This study aimed at (i) mapping the noise pollution levels at various locations of Faisalabad city; (ii) comparing noise pollution levels in the morning, the afternoon, and the evening for each source; and (iii) assessing nonauditory effects of noise on human health. Two industries and 43 famous/busy locations of Faisalabad Sadar were selected to study noise pollution by using the sound level meter for the period of 24 h. A questionnaire-based survey was carried out near the sampling points to get a public perception about the health impacts of noise pollution. The measured equivalent sound pressure levels (SPLeq) were higher than the permissible limits at all the sampling locations during morning, afternoon, and evening hours. The maximum sound pressure level (SPL_max) was 102 dB inside the production unit in the afternoon at Mian Muhammad Siddiq Textile Loom industry. The average SPL was found at State Bank road (102 dB), Children's Hospital (101 dB), Jhang Bazar (100 dB) in the afternoon and at Punjab Medical College in the evening (97 dB). Based on the survey, 94% of respondents reported headache, 76% sleeplessness, 74% hypertension, 74% physiological stress, 64% elevated blood pressure levels, and 60% dizziness due to noise. Noise pollution is higher than the standard limits and causes auditory as well as nonauditory effects on humans. The vehicles and industrial machinery should be maintained, and sound proofing and protection equipment should be provided to the workforce in order to protect them from extreme noise levels.

The interactive effect of occupational noise on attention and short-term memory: A pilot study

Introduction:

Human performance is influenced by several job-related factors and workplace conditions, including occupational noise. This influence can occur at sound pressure levels lower than the ones that cause physiological damage, such as hearing loss, being mediated by the noise characteristics. However, studies concerning this issue are still scarce. Study.

Aim:

The aim of this study was to investigate the effects of three noise conditions on attention and short-term memory: standard condition (C1), environmental noise without alarm sounds (C2), and environmental noise with alarm sounds (C3).

Materials and Methods:

First, noise levels were measured during a normal workweek in a fast food establishment. Second, an experiment was designed to simulate the noise normally prevailing in the workplace. The noise levels were fixed at 45 ± 0.3 dB(A) (C1), 60 ± 0.4 dB(A) (C2), and 68 ± 0.4 dB(A) (C3). The influence of noise on participants’ attention and short-term memory was assessed with the following test battery: serial recall, response inhibition, and Stroop interference. Because annoyance, stress, and discomfort perceptions during the tests can influence results, visual analog scales to assess these variables were applied in the end of each trial. Fifteen undergraduate students were included in this pilot study (20–23 years; M = 21.6; SD = 0.8; all female).

Results:

The results demonstrated that participants’ performance during the tests was lower in C3, that is, the number of errors was higher and the reaction time longer. Participants also experienced higher levels of discomfort, stress, and annoyance perceptions in this condition. However, task performance was not found to be influenced by these perceptions.

Conclusion:

This study provided important insights about the different noise conditions that workers are exposed in a fast food restaurant, and how they influence participants’ performance. Further research should involve workers, exploring how these conditions are implicated in their performance in the field.

Representation of amplified speech at cortical level in good and poor hearing aid performers

Introduction

Hearing aid users reject their own hearing aid because of annoyance with background noise. The reason for dissatisfaction is located anywhere from the hearing aid microphone to the integrity of neurons along the auditory pathway. In this preview, the output of hearing aid was recorded at the level of ear canal and at auditory cortex in good and poor hearing aid users, who were classified using acceptable noise level.

Objective

To study the representation of amplified speech in good and poor hearing aid performers.

Methods

A total of 60 participants (age ranged 15–65 years) with moderate bilateral sensorineural hearing impairment grouped into good (n = 35) and poor (n = 25) hearing aid performers. Gap detection test and aided SNR 50 were administered. In addition, ear canal acoustic measures and cortical auditory evoked potentials were recorded in unaided and aided conditions at 65 dB SPL.

Results

Hearing aid minimally alters temporal contrast of speech reflected in envelope difference index. Although having similar temporal impairment, acoustic characteristics of amplified speech sounds and SNR 50 scores from both groups, the aided cortical auditory evoked potentials surprisingly showed significant earlier latencies and higher amplitudes in good performers than poor performers. In addition, good and poor performers classified based on annoyance level was predicted by latencies of 2N1 and 2P2 components of acoustic change complex. Further, a follow-up revealed hearing aid use has relation with acceptance towards noise.

Conclusion

Participants who are willing to accept noise from those who are not willing to accept noise have subtle physiological changes evident at the auditory cortex, which supports the hearing aid usage.

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

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

Exposure to road traffic noise: Annoyance, perception and associated factors among Brazil's adult population

BACKGROUND

One of the major environmental problems of the modern world is noise. A health-related marker of environmental noise exposure that can be considered a predictor of annoyance is noise sensitivity. The aim of this study was to ascertain the correlation between levels of exposure to road traffic noise in residential areas and the resulting annoyance based on the perception and sensitivity reported.

METHODS

The study involved noise assessment, with the creation of noise maps of the neighborhood in the city of São Paulo, Brazil, and application of a questionnaire to ascertain the perception of the residents of the neighborhood, regarding the effects of this exposure.

RESULTS

The noise levels at all the measured points were found to exceed the critical level for the area, 55 dB(A). A total of 225 interviews were conducted. Noise-related annoyance was reported by 48.4% of the respondents. Associations were observed between living in areas exposed to traffic noise and feeling annoyed with this noise (p < 0.001).

CONCLUSIONS

These findings suggest the importance of reviewing and updating Brazilian public policies regarding environmental noise. We found a high prevalence of annoyance reports, as well as aspects indicative of sensitivity to noise exposure.

Transportation noise exposure, noise annoyance and respiratory health in adults: A repeated-measures study

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.

Tinnitus: The Sound of Stress?

Background:

Emotional stress is frequently associated with otologic symptoms as tinnitus and dizziness. Stress can contribute to the beginning or worsening of tinnitus.

Objective:

The objective of the study is to evaluate the presence of stress symptoms in patients with chronic, subjective tinnitus, and correlate its presence to annoyance associated with tinnitus.

Methods:

This is a cross-sectional study. One hundred and eighty patients with chronic, subjective tinnitus were included. Patients answered the Tinnitus Handicap Inventory (THI) to evaluate the impact of tinnitus in the quality of life and answered the Lipp's inventory symptoms of stress for adults (ISSL). The data obtained was organized using Excel® 2010, mean values, linear regression and p-value were calculated.

Results:

Of the 180 patients included in the study, 117 (65%) had stress symptoms, 52 of the 117 (44%) were in the resistance phase and 23 of the 117 (20%) in the exhaustion phase, the remaining was in the alert phase. There was a clear progressive increase in stress as THI raised, with more impact of tinnitus in quality of life.

Conclusion:

The presence of stress symptoms, measured by ISSL was observed in most of our patients with chronic subjective tinnitus, specially in the resistance and exhaustion phases and it is directly associated with tinnitus annoyance.

Multiple pathways link urban green- and bluespace to mental health in young adults

BACKGROUND

A growing body of scientific literature indicates that urban green- and bluespace support mental health; however, little research has attempted to address the complexities in likely interrelations among the pathways through which benefits plausibly are realized.

OBJECTIVES

The present study examines how different plausible pathways between green/bluespace and mental health can work together. Both objective and perceived measures of green- and bluespace are used in these models.

METHODS

We sampled 720 students from the city of Plovdiv, Bulgaria. Residential greenspace was measured in terms of the Normalized Difference Vegetation Index (NDVI), tree cover density, percentage of green areas, and Euclidean distance to the nearest green space. Bluespace was measured in terms of its presence in the neighborhood and the Euclidean distance to the nearest bluespace. Mental health was measured with the 12-item form of the General Health Questionnaire (GHQ-12). The following mediators were considered: perceived neighborhood green/bluespace, restorative quality of the neighborhood, social cohesion, physical activity, noise and air pollution, and environmental annoyance. Structural equation modelling techniques were used to analyze the data.

RESULTS

Higher NDVI within a 300 m buffer around the residence was associated with better mental health through higher perceived greenspace; through higher perceived greenspace, leading to increased restorative quality, and subsequently to increased physical activity (i.e., serial mediation); through lower noise exposure, which in turn was associated with lower annoyance; and through higher perceived greenspace, which was associated with lower annoyance. Presence of bluespace within a 300 m buffer did not have a straightforward association with mental health owing to competitive indirect paths: one supporting mental health through higher perceived bluespace, restorative quality, and physical activity; and another engendering mental ill-health through higher noise exposure and annoyance.

CONCLUSIONS

We found evidence that having more greenspace near the residence supported mental health through several indirect pathways with serial components. Conversely, bluespace was not clearly associated with mental health.

Pathways linking residential noise and air pollution to mental ill-health in young adults

BACKGROUND

Recent years have seen growing, but still tentative, evidence of the potential associations of environmental noise and air pollution with mental disorders. In the present study, we aimed to examine the associations between residential noise and air pollution exposures and general mental health in young adults with a focus on underlying processes METHODS: We sampled 720 students (18-35 years) from one university in the city of Plovdiv, Bulgaria. Residential noise (L_Aeq; day equivalent noise level) and air pollution (NO₂) were assessed at participant's residential address by land use regression models. General mental health was measured with a short form of the General Health Questionnaire (GHQ). The following putative mediators were considered: annoyance from environmental pollution, sleep disturbance, restorative quality of the neighborhood, neighborhood social cohesion, and commuting/leisure time physical activity. Structural equation modeling was used to analyze the theoretically-indicated interplay between exposures, mediators, and GHQ.

RESULTS

We observed an association between higher L_Aeq and GHQ, in which environmental annoyance and neighborhood restorative quality emerged as key mediators. First, L_Aeq was associated with higher annoyance, and through it with lower restorative quality, and then in turn with lower physical activity, and thus with higher GHQ. Simultaneously, higher annoyance was associated with higher sleep disturbance, and thereby with higher GHQ. NO₂ had no overall association with GHQ, but it was indirectly associated with it through higher annoyance, lower restorative quality, and lower physical activity working in serial.

CONCLUSION

We found evidence that increased residential noise was related to mental ill-health through several indirect pathways. Air pollution was associated with mental health only indirectly.

Urine Cotinine Should Be Involved in Initial Evaluation of Tinnitus in Adolescents

Objectives

Smoking is associated with hearing loss, while the correlation between tinnitus and smoking is not fully elucidated. This study aimed to evaluate risk factors of tinnitus in adolescents in terms of smoking, and we identified a rectifiable parameter that can be serially monitored.

Methods

A cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey, with 2,782 participants aged 12 to 18 years, from 2008 through 2011. Participants with history of ear disease, hearing loss, and inadequate responses to questionnaires were excluded. We investigated the prevalence of tinnitus and tinnitus-related annoyance by questionnaire and sought potential risk factors in blood and urine tests and smoking history.

Results

The prevalence of tinnitus in the 12- to 18-year-old population was 17.5%, with 3.3% reporting tinnitus-related annoyance. On univariate analysis, the prevalence of tinnitus increased with age (P<0.001) and was higher among girls (P=0.012). Blood tests and urinalysis showed significant correlation between tinnitus and red blood cell count, alkaline phosphatase levels, and urine cotinine (P=0.002, P<0.001, P=0.018, respectively). In multivariate analysis, the urine cotinine level was the only parameter associated with tinnitus (odds ratio, 1.000; 95% confidence interval, 0.999 to 1.000; P=0.038). Smoking was also significantly correlated with tinnitus (P=0.043), and amount of smoking with tinnitus-related annoyance (P=0.045). However, current smoking and past smoking were not correlated with tinnitus.

Conclusion

Urine cotinine may be a rectifiable marker for management of tinnitus in adolescents. This suggests that smoking cessation should be incorporated in the management of tinnitus in adolescents.

Comparative analysis of spatio-temporal exposure assessment methods for estimating odor-related responses in non-urban populations

The assessment of air pollution exposures in epidemiological studies does not always account for spatio-temporal variability of pollutants concentrations. In the case of odor studies, a common approach is to use yearly averaged odorant exposure estimates with low spatial resolution, which may not capture the spatio-temporal variability of emissions and therefore distort the epidemiological results. This study explores the use of different exposure assessment methods for time-variant ammonia exposures with high spatial resolution, in rural communities exposed to odors from agricultural and livestock farming activities. Exposure estimations were based on monthly ammonia concentrations from emission-dispersion models. Seven time-dependent residential NH₃ exposures variables were investigated: 1) Annual mean of NH₃ exposures; 2) Maximum annual NH₃ exposure; 3) Area under the exposure curve; 4) Peak area; 5) Peak-to-mean ratio; 6) Area above the baseline (annual mean of NH₃ exposures); and 7) Maximum positive slope of the exposure curve. We developed binomial and multinomial logistic regression models for frequency of odor perception and odor annoyance responses based on each temporal exposure variable. Odor responses estimates, goodness of fit and predictive abilities derived from each model were compared. All time-dependent NH₃ exposure variables, except peak-to-mean ratio, were positively associated with odor perception and odor annoyance, although the results differ considerably in terms of magnitude and precision. The best goodness of fit of the predictive binomial models was obtained when using maximum monthly NH₃ exposure as exposure assessment variable, both for odor perception and annoyance. The best predictive performance for odor perception was found when annual mean was used as exposure variable (accuracy=71.82%, Cohen's Kappa=0.298) whereas odor annoyance was better predicted when using peak area (accuracy=68.07%, Cohen's Kappa=0.290). Our study highlights the importance of taking temporal variability into account when investigating odor-related responses in non-urban residential areas.

Survey of the effect of odour impact on communities

In the context of environmental malodour, surveys are valuable as they allow for the relatively detailed analysis of multiple factors pertaining to odour perception and subsequent reaction. However, the causes for an individual to experience odour impact while a neighbour will not are still not understood. The goal of this current survey design was to consolidate varying research paths for surveys within the environmental odour research space. This survey investigated the area of effect for wastewater treatment plants by using stratified random sampling techniques that radiated from the industrial areas. Additionally, this survey provided a "non-alerted" response to environmental malodour that represents a step forward for ecological validity. We found a small number of items relating to odour annoyance and home ownership that can be used in order to predict odour impact for individual community members. However, we also did not find any relationship with odour impact and perceived control. This survey design and analysis reconciles the varied approaches towards community surveys administered in prior literature, as well as providing information to improve future community engagement policies.

Road traffic noise and determinants of saliva cortisol levels among adolescents

OBJECTIVES

The understanding of determinants for saliva cortisol levels in adolescents is limited. This study investigated the role of road traffic noise exposure, noise annoyance and various other factors for saliva cortisol levels.

METHODS

We collected morning and evening saliva samples from 1751 adolescents from the BAMSE birth cohort based in Stockholm County. Façade noise levels from road traffic were estimated at the residences of the study subjects and repeated questionnaires and medical examinations provided extensive information on various exposures and conditions, including annoyance to noise from different sources. Cortisol was measured using radioimmunoassay. Associations between determinants and saliva cortisol levels were analysed using linear regression.

RESULTS

Morning saliva cortisol levels were significantly higher in females than in males (geometric mean 42.4 and 35.0 nmol/l, respectively) as well as in subjects with allergy related diseases. Height and age were related to saliva cortisol levels as well as sampling season. Road traffic noise exposure was not associated with saliva cortisol, however, annoyance to noise tended to increase the levels. Saliva cortisol levels appeared particularly high among those who were highly annoyed and exposed to road traffic noise levels ≥ 55 dB L_den (50.5 nmol/l, p = 0.02).

CONCLUSION

Our findings suggest that individual perception of noise may be of importance for saliva cortisol levels. The results also point to the complexity of using saliva cortisol as a marker of noise exposure in adolescents.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact sound: a pilot study

BACKGROUND

Recently, noise coming from the neighborhood via floor wall has become a great social problem. The noise between the floors can be a cause of physical and psychological problems, and the different types of floor impact sound (FIS) may have the different effects on the human's body and mind. The purpose of this study is to assess the responses of subjective feeling, task performance ability, cortisol and HRV for the various types of floor impact.

METHODS

Ten men and 5 women were enrolled in our study, and the English listening test was performed under the twelve different types of FIS, which were made by the combinations of bang machine (B), tapping machine (T), impact ball (I) and sound-proof mattress (M). The 15 subjects were exposed to each FIS for about 3 min, and the subjective annoyance, performance ability (English listening test), cortisol level of urine/saliva and heart rate variability (HRV) were examined. The sound pressure level (SPL) and frequency of FIS were analyzed. Repeated-measures ANOVA, paired t-test, Wilcoxon signed rank test were performed for data analysis.

RESULTS

The SPL of tapping machine (T) was reduced with the soundproof mattress (M) by 3.9-7.3 dBA. Impact ball (I) was higher than other FIS in low frequency (31.5-125 Hz) by 10 dBA, and tapping machine (T) was higher than other FIS in high frequency (2-4 k Hz) by 10 dBA. The subjective annoyance is highest in the combination of bang machine and tapping machine (BT), and next in the tapping machine (T). The English listening score was also lowest in the BT, and next in T. The difference of salivary cortisol levels between various types of FIS was significant (p = 0.003). The change of HRV parameters by the change of FIS types was significant in some parameters, which were total power (TP) (p = 0.004), low frequency (LF) (p = 0.002) and high frequency (HF) (p = 0.011).

CONCLUSIONS

These results suggest that the human's subjective and objective responses were different according to FIS types and those combinations.

Human annoyance, acceptability and concern as responses to vibration from the construction of Light Rapid Transit lines in residential environments

The aim of this paper is to investigate the use of different self-reported measures for assessing the human response to environmental vibration from the construction of an urban LRT (Light Rapid Transit) system. The human response to environmental stressors such as vibration and noise is often expressed in terms of exposure-response relationships that describe annoyance as a function of the magnitude of the vibration. These relationships are often the basis of noise and vibration policy and the setting of limit values. This paper examines measures other than annoyance by expressing exposure-response relationships for vibration in terms of self-reported concern about property damage and acceptability. The exposure-response relationships for concern about property damage and for acceptability are then compared with those for annoyance. It is shown that concern about property damage occurs at vibration levels well below those where there is any risk of damage. Earlier research indicated that concern for damage is an important moderator of the annoyance induced. Acceptability, on the other hand, might be influenced by both annoyance and concern, as well as by other considerations. It is concluded that exposure-response relationships expressing acceptability as a function of vibration exposure could usefully complement existing relationships for annoyance in future policy decisions regarding environmental vibration. The results presented in this paper are derived from data collected through a socio-vibration survey (N=321) conducted for the construction of an urban LRT in the United Kingdom.

Noise exposure of residential areas along LRT lines in a mountainous city

Light rapid transit (LRT) has been widely used in a number of Chinese cities in recent years. Different from plain cities, the urban areas in mountainous cities are featured with dense road networks and high density of buildings. The noise impact of urban LRT could be more complex and significant due to the special morphological conditions in mountainous cities. This paper aims to investigate the noise exposure of residential areas along LRT lines in a typical mountainous city, namely Chongqing in Southwest China, through a series of field measurements and questionnaire surveys. Eight typical spatial configurations were classified to represent the relationships between LRT lines and urban mountainous environment. Both the outdoor and indoor acoustic environment of residential areas along LRT lines largely exceeded the national standards by up to 15dBA, with dominant at low frequencies. The LRT noises tend to be more dominant on the 'below track' and 'passing through' rather than 'above track' areas or 'facing towards' locations. Good agreements were achieved between acoustic measurements and subjective evaluations from the local residents. Residents in the noisier areas tend to be more annoyed and influenced by the LRT noise, and 63.2% of interviewed residents once were awakened by the LRT noise. Among various urban noise sources, LRT noise resulted in the largest percentages of highly annoyed residents (30.9%), and acoustic environment was identified by 42.2% of the participants as the most urgent environmental factor to be improved. The preferred control strategies for LRT noise are possible but limited in practice. Moreover, noise sensitivity and age might significantly affect LRT noise annoyance and impact, whereas window glazing and residence time have no significant influence.

Changes in quality of life and perceptions of general health before and after operation of wind turbines

Ontario is Canada's provincial leader in wind energy, with over 4000 MW of installed capacity supplying approximately five percent of the province's electricity demand. Wind energy is now one of the fastest-growing sources of renewable power in Canada and many other countries. However, its possible negative impact on population health, as a new source of environmental noise, has raised concerns for people living in proximity to wind turbines (WTs). The aims of this study were to assess the effect of individual differences and annoyance on the self-reported general health and health-related quality of life (QOL) of nearby residents, using a pre- and post-exposure design. Prospective cohort data were collected before and after WT operations, from the individuals (n = 43) in Ontario, Canada. General health and QOL metrics were measured using standard scales, such as SF12, life satisfaction scales developed by Diener (SWLS) and the Canadian Community Health Survey (CCHS-SWL). The mean values for the Mental Component Score of SF12 (p = 0.002), SWLS (p < 0.001), and CCHS-SWL (p = 0.044) significantly worsened after WT operation for those participants who had a negative attitude to WTs, who voiced concerns about property devaluation, and/or who reported being visually or noise annoyed.

Long-term transportation noise annoyance is associated with subsequent lower levels of physical activity

Noise annoyance (NA) might lead to behavioral patterns not captured by noise levels, which could reduce physical activity (PA) either directly or through impaired sleep and constitute a noise pathway towards cardiometabolic diseases. We investigated the association of long-term transportation NA and its main sources (aircraft, road, and railway) at home with PA levels. We assessed 3842 participants (aged 37-81) that attended the three examinations (SAP 1, 2, and 3 in years 1991, 2001 and 2011, respectively) of the population-based Swiss cohort on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA). Participants reported general 24-h transportation NA (in all examinations) and source-specific NA at night (only SAP 3) on an ICBEN-type 11-point scale. We assessed moderate, vigorous, and total PA from a short-questionnaire (SAP 3). The main outcome was moderate PA (active/inactive: cut-off≥150min/week). We used logistic regression including random effects by area and adjusting for age, sex, socioeconomic status, and lifestyles (main model) and evaluated potential effect modifiers. We analyzed associations with PA at SAP 3 a) cross-sectionally: for source-specific and transportation NA in the last year (SAP 3), and b) longitudinally: for 10-y transportation NA (mean of SAP 1+2), adjusting for prior PA (SAP 2) and changes in NA (SAP 3-2). Reported NA (score≥5) was 16.4%, 7.5%, 3%, and 1.1% for 1-year transportation, road, aircraft, and railway at SAP 3, respectively. NA was greater in the past, reaching 28.5% for 10-y transportation NA (SAP 1+2). The 10-y transportation NA was associated with a 3.2% (95% CI: 6%-0.2%) decrease in moderate PA per 1-NA rating point and was related to road and aircraft NA at night in cross-sectional analyses. The longitudinal association was stronger for women, reported daytime sleepiness or chronic diseases and it was not explained by objectively modeled levels of road traffic noise at SAP 3. In conclusion, long-term NA (related to psychological noise appraisal) reduced PA and could represent another noise pathway towards cardiometabolic diseases.

An assessment of quality of life using the WHOQOL-BREF among participants living in the vicinity of wind turbines

Living within the vicinity of wind turbines may have adverse impacts on health measures associated with quality of life (QOL). There are few studies in this area and inconsistent findings preclude definitive conclusions regarding the impact that exposure to wind turbine noise (WTN) may have on QOL. In the current study (officially titled the Community Noise and Health Study or CNHS), the World Health Organization QOL-BREF (WHOQOL-BREF) questionnaire provided an evaluation of QOL in relation to WTN levels among randomly selected participants aged 18-79 (606 males, 632 females) living between 0.25 and 11.22 km from wind turbines (response rate 78.9%). In the multiple regression analyses, WTN levels were not found to be related to scores on the Physical, Psychological, Social or Environment domains, or to rated QOL and Satisfaction with Health questions. However, some wind turbine-related variables were associated with scores on the WHOQOL-BREF, irrespective of WTN levels. Hearing wind turbines for less than one year (compared to not at all and greater than one year) was associated with improved (i.e. higher) scores on the Psychological domain (p=0.0108). Lower scores on both the Physical and Environment domains (p=0.0218 and p=0.0372, respectively), were observed among participants reporting high visual annoyance toward wind turbines. Personal benefit from having wind turbines in the area was related to higher scores on the Physical domain (p=0.0417). Other variables significantly related to one or more domains, included sex, age, marital status, employment, education, income, alcohol consumption, smoking status, chronic diseases and sleep disorders. Collectively, results do not support an association between exposure to WTN up to 46 dBA and QOL assessed using the WHOQOL-BREF questionnaire.

Acceptable noise level as a deciding factor for prescribing hearing aids for older adults with cochlear hearing loss - A scoping review

Older adults often find it difficult to perceive speech, especially in noisy conditions. Though hearing aid is one of the rehabilitative devices available to older adults to alleviate hearing loss, some of them may experience annoyance through hearing aid and hence reject it, may be due to circuitry noise and/or background noise. Acceptable noise level is a direct behavioural measure to estimate the extent of how much a person is able to put up with noise while simultaneously listening to speech. Acceptable noise level is a central auditory measure and it is not influenced by age, gender, presentation level or speaker. Using this measure, we can quantify the annoyance level experienced by an individual. This information is of utmost importance and caution should be paid before setting the parameters in hearing aid, especially for those who are unable to accept noise. In this review article, an attempt has been made to document how to optimize the hearing aid program by setting parameters such as noise reduction circuit, microphone sensitivity and gain. These adjustments of parameters might help to reduce rejection rate of hearing aids, especially in those individuals who are annoyed by background noise.

The effect of wind turbine noise on sleep and quality of life: A systematic review and meta-analysis of observational studies

Noise generated by wind turbines has been reported to affect sleep and quality of life (QOL), but the relationship is unclear. Our objective was to explore the association between wind turbine noise, sleep disturbance and quality of life, using data from published observational studies. We searched Medline, Embase, Global Health and Google Scholar databases. No language restrictions were imposed. Hand searches of bibliography of retrieved full texts were also conducted. The reporting quality of included studies was assessed using the STROBE guidelines. Two reviewers independently determined the eligibility of studies, assessed the quality of included studies, and extracted the data. We included eight studies with a total of 2433 participants. All studies were cross-sectional, and the overall reporting quality was moderate. Meta-analysis of six studies (n=2364) revealed that the odds of being annoyed is significantly increased by wind turbine noise (OR: 4.08; 95% CI: 2.37 to 7.04; p<0.00001). The odds of sleep disturbance was also significantly increased with greater exposure to wind turbine noise (OR: 2.94; 95% CI: 1.98 to 4.37; p<0.00001). Four studies reported that wind turbine noise significantly interfered with QOL. Further, visual perception of wind turbine generators was associated with greater frequency of reported negative health effects. In conclusion, there is some evidence that exposure to wind turbine noise is associated with increased odds of annoyance and sleep problems. Individual attitudes could influence the type of response to noise from wind turbines. Experimental and observational studies investigating the relationship between wind turbine noise and health are warranted.