Noise pollution: non-auditory effects on health

Stress Response and Hearing Loss Differentially Contribute to Dynamic Alterations in Hippocampal Neurogenesis and Microglial Reactivity in Mice Exposed to Acute Noise Exposure

Noise-induced hearing loss (NIHL) is one of the most prevalent forms of acquired hearing loss, and it is associated with aberrant microglial status and reduced hippocampal neurogenesis; however, the nature of these associations is far from being elucidated. Beyond its direct effects on the auditory system, exposure to intense noise has previously been shown to acutely activate the stress response, which has increasingly been linked to both microglial activity and adult hippocampal neurogenesis in recent years. Given the pervasiveness of noise pollution in modern society and the important implications of either microglial activity or hippocampal neurogenesis for cognitive and emotional function, this study was designed to investigate how microglial status and hippocampal neurogenesis change over time following acoustic exposure and to analyze the possible roles of the noise exposure-induced stress response and hearing loss in these changes. To accomplish this, adult male C57BL/6J mice were randomly assigned to either a control or noise exposure (NE) group. Auditory function was assessed by measuring ABR thresholds at 20 days post noise exposure. The time-course profile of serum corticosterone levels, microglial status, and hippocampal neurogenesis during the 28 days following noise exposure were quantified by ELISA or immunofluorescence staining. Our results illustrated a permanent moderate-to-severe degree of hearing loss, an early but transient increase in serum corticosterone levels, and time-dependent dynamic alterations in microglial activation status and hippocampal neurogenesis, which both present an early but transient change and a late but enduring change. These findings provide evidence that both the stress response and hearing loss contribute to the dynamic alterations of microglia and hippocampal neurogenesis following noise exposure; moreover, noise-induced permanent hearing loss rather than noise-induced transient stress is more likely to be responsible for perpetuating the neurodegenerative process associated with many neurological diseases.

Long-Term Exposure to Transportation Noise and Risk for Type 2 Diabetes in a Nationwide Cohort Study from Denmark

BACKGROUND

Epidemiologic studies have linked transportation noise to increased morbidity and mortality, particularly for cardiovascular outcomes. However, studies investigating metabolic outcomes such as diabetes are limited and have focused only on noise exposures estimated for the loudest residential façade.

OBJECTIVES

We aimed to examine the influence of long-term residential exposure to transportation noise at the loudest and quietest residential façades and the risk for type 2 diabetes.

METHODS

Road traffic and railway noise exposures (Lden) at the most and least exposed façades were estimated for all dwellings in Denmark during 1990-2017. Aircraft noise was estimated in 5-dB categories. Ten-year time-weighted mean noise exposures were estimated for 3.56 million individuals ≥35 years of age. From 2000 to 2017, 233,912 incident cases of type 2 diabetes were identified using hospital and prescription registries, with a mean follow-up of 12.9 y. We used Cox proportional hazards models adjusting for individual- and area-level covariates and long-term residential air pollution. The population-attributable fraction (PAF) was also computed.

RESULTS

Hazard ratios (HRs) and 95% confidence intervals (CIs) for type 2 diabetes in association with 10-dB increases in 10-y mean road traffic noise at the most and least exposed façades, respectively, were 1.05 (95% CI: 1.04, 1.05) and 1.09 (95% CI: 1.08, 1.10). Following subsequent adjustment for fine particulate matter [particulate matter ≤2.5μm in aerodynamic diameter] (10-y mean), the HRs (CIs) were 1.03 (95% CI: 1.03, 1.04) and 1.08 (95% CI: 1.07, 1.09), respectively. For railway noise, the HRs per 10-dB increase in 10-y mean exposure were 1.03 (95% CI: 1.02, 1.04) and 1.02 (95% CI: 1.01, 1.04) for the most and least exposed façades, respectively. Categorical models supported a linear exposure-outcome relationship for road traffic noise and, to a lesser extent, for railway noise. Aircraft noise >45 dB was associated with a 1-4% higher likelihood of type 2 diabetes compared with those who were unexposed. We found road traffic and railway noise associated with a PAF of 8.5% and 1.4%, respectively, of the diabetes cases.

DISCUSSION

Long-term exposure to road, railway, and possibly aircraft traffic noise was associated with an increased risk of type 2 diabetes in a nationwide cohort of Danish adults. Our findings suggest that diabetes should be included when estimating the burden of disease due to transportation noise. https://doi.org/10.1289/EHP9146.

Research on Acoustic Environment in the Building of Nursing Homes Based on Sound Preference of the Elderly People: A Case Study in Harbin, China

Nursing homes are the facilities where the elderly conduct their daily activities. This may lead to a complicated acoustic environment which would potentially affect the ability of the elderly to function. In this study, the main indoor public space of a nursing home in Harbin was taken as the research object, and the methods of field observation, sound measurement, and questionnaire survey were used to explore the sound perception and preference of the elderly. The results revealed that in terms of the temporal and spatial distribution of sound pressure level (SPL), the unit living space had the highest SPL, which was above 60 dB (A). The reverberation time (RT) of the unit living space, medical and health care center corridor, was 2.15 and 2.13 s, respectively, at a frequency of 1,000 Hz, which was within the discomfort range. The results also revealed that an acoustic environment had a strong correlation with humidity and a weak correlation with temperature. However, no significant correlation could be assessed with a luminous environment. The elderly people were generally willing to accept the natural sound sources. The factors of gender and offspring numbers had no significant impact on the evaluation of acoustic environment comfort, whereas marriage and income status affected the comfort. This study may help improve the quality of life of the elderly in the nursing home and provide a reference for the construction and design of pension facilities.

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.

Psychophysiological responses to potentially annoying heating, ventilation, and air conditioning noise during mentally demanding work

Exposure to noise-or unwanted sound-is considered a major public health issue in the United States and internationally. Previous work has shown that even acute noise exposure can influence physiological response in humans and that individuals differ markedly in their susceptibility to noise. Recent research also suggests that specific acoustic properties of noise may have distinct effects on human physiological response. Much of the existing research on physiological response to noise consists of laboratory studies using very simple acoustic stimuli-like white noise or tone bursts-or field studies of longer-term workplace noise exposure that may neglect acoustic properties of the noise entirely. By using laboratory exposure to realistic heating, ventilation, and air conditioning (HVAC) noise, the current study explores the interaction between acoustic properties of annoying noise and individual response to working in occupational noise. This study assessed autonomic response to two acoustically distinct noises while participants performed cognitively demanding work. Results showed that the two HVAC noises affected physiological arousal in different ways. Individual differences in physiological response to noise as a function of noise sensitivity were also observed. Further research is necessary to link specific acoustic characteristics with differential physiological responses in humans.

Characterization of CaCO3 Filled Poly(lactic) Acid and Bio Polyethylene Materials for Building Applications

Noise pollution has been identified as a cause of a broad spectrum of diseases, motivating researchers to identify building materials capable of attenuating this pollution. The most common solution is the use of gypsum boards, which show a good response for low frequencies but have a poorer response for high frequencies. In addition, due to environmental concerns associated with buildings, the use of materials that minimize environmental impacts must be favored. In this research, two biopolymers, a poly(lactic) acid and a bio-polyethylene, were filled with two typologies of calcium carbonate, and their soundproofing properties were tested using impedance tubes. In addition, the morphology of the fillers was characterized, and here we discuss its impact on the mechanical properties of the composites. The results showed that the incorporation of calcium carbonate into bio-based thermoplastic materials can represent a strong alternative to gypsum, because their mechanical properties and sound barrier performance are superior. In addition, the inclusion of mineral fillers in thermoplastic materials has a positive impact on production costs, in addition to preserving the advantages of thermoplastics in terms of processing and recycling. Although the use of carbonate calcium decreases the mechanical properties of the materials, it enables the production of materials with insulation that is four-fold higher than that of gypsum. This demonstrates the potential of these materials as building lightweight solutions.

Comparison of mice' sperm parameters exposed to some hazardous physical agents

The present study was aimed to compare the effects of exposure to noise, vibration, lighting, and microwave on male mice' sperm parameters. The mice were randomly assigned to five groups of eight, which comprised of the unexposed group and exposure groups including the lighting (1000 lux), noise (100 dB(A)), vibration (acceleration of 1.2 m/s2) and microwave (power density of 5 watts). The exposure groups were subjected to the four agents for 8 hours a day, 5 days a week during a 2-week period. Semen analysis were done according to World Health Organization guidelines. The highest significant mean difference in sperm count (-1.35×106/mL) had being observed between the microwave group and the control one (P=0.001). The highest difference in immotile percent (25.88 %) had being observed between the noise group and the control one (P=0.001). The highest difference in normal morphology (-27.06 %) observed between the lighting exposure group and the control group (P=0.001). The four agents can cause changes in different sperm parameters, however for definite conclusion; more laboratory and field studies are required. In total, exposure to microwave has had the greatest effect on sperm count and exposure to light has had the greatest effect on normal morphology and non-progressive motility. Moreover, exposure to noise has had the greatest effect on progressive motility and immotile percent, respectively.

Effect of COVID-19 lockdown on noise pollution levels in an Indian city: a case study of Kanpur

Noise pollution is an emerging environmental threat, prolonged exposure of which can cause annoyance, sleep disturbance, hypertension, psychiatric disorders, and also hormonal dysfunction. Among all the sources of noise pollution, the noise generated by road vehicle traffic significantly affects the quality of urban environments. Concerning the recent imposition of COVID-19 societal lockdown, this study attempts to investigate the impacts of COVID-19 lockdown on the changes in noise pollution levels before, during, and after lockdown phase in different residential, commercial, industrial, and silence zones of the city of Kanpur, India. Utilizing data collected from portable environmental sensors, the average noise levels before lockdown and during lockdown were found to be in the range of 44.85 dB to 79.57 dB and 38.55 dB to 57.79 dB, respectively, for different zones. Although a significant reduction in the noise levels was observed during lockdown, except for commercial zone, all other monitoring stations had reported sound levels quite higher than the recommended noise limits set by the Central Pollution Control Board (CPCB) of India. Results further indicated that the impact of road traffic noise on risk of high annoyance and sleep disturbance was found to be lower during lockdown as compared to that of pre-lockdown and unlock phase. While the annoyance level in residential (86.23%), industrial (87.44%), and silence (84.47%) was higher in pre-lockdown period, it reduced to 41.25, 50.28, and 43.07% in the lockdown phase. Even the risk of sleep disturbance in the residential zone was found to reduce from 37.96% during pre-lockdown to 14.72% during lockdown phase. Several noise mitigation strategies are also proposed, which may indeed pave the way for devising noise control measures in the local and regional level.

Methods for Noise Event Detection and Assessment of the Sonic Environment by the Harmonica Index

Noise annoyance depends not only on sound energy, but also on other features, such as those in its spectrum (e.g., low frequency and/or tonal components), and, over time, amplitude fluctuations, such as those observed in road, rail, or aircraft noise passages. The larger these fluctuations, the more annoying a sound is generally perceived. Many algorithms have been implemented to quantify these fluctuations and identify noise events, either by looking at transients in the sound level time history, such as exceedances above a fixed or time adaptive threshold, or focusing on the hearing perception process of such events. In this paper, four criteria to detect sound were applied to the acoustic monitoring data collected in two urban areas, namely Andorra la Vella, Principality of Andorra, and Milan, Italy. At each site, the 1 s A-weighted short LAeq,1s time history, 10 min long, was available for each hour from 8:00 a.m. to 7:00 p.m. The resulting 92-time histories cover a reasonable range of urban environmental noise time patterns. The considered criteria to detect noise events are based on: (i) noise levels exceeding by +3 dB the continuous equivalent level LAeqT referred to the measurement time (T), criteria used in the definition of the Intermittency Ratio (IR) to detect noise events; (ii) noise levels exceeding by +3 dB the running continuous equivalent noise level; (iii) noise levels exceeding by +10 dB the 50th noise level percentile; (iv) progressive positive increments of noise levels greater than 10 dB from the event start time. Algorithms (iii) and (iv) appear suitable for notice-event detection; that is, those that (for their features) are clearly perceived and potentially annoy exposed people. The noise events detected by the above four algorithms were also evaluated by the available anomalous noise event detection (ANED) procedure to classify them as produced by road traffic noise or something else. Moreover, the assessment of the sonic environment by the Harmonica index was correlated with the single event level (SEL) of each event detected by the four algorithms. The threshold value of 8 for the Harmonica index, separating the “noisy” from the “very noisy” environments, corresponds to lower SEL levels for notice-events as identified by (iii) and (iv) algorithms (about 88–89 dB(A)) against those identified by (i) and (ii) criteria (92 dB(A)).

Soundscape Evaluation Comparison of Outdoor Activity Space Between Gated and Open Communities

In communities, outdoor activity space is utilized most often by older adults and children, and the soundscape is very important for its quality. For different community planning modes, such as gated and open communities, focus should be on different soundscape enhancement strategies for outdoor spaces. In this paper, typical samples of activity spaces in a gated community and in an open community were used. The comparison was conducted through soundscape evaluation including an analysis of the dominance of various sound sources, noise annoyance, and the perceptual dimensions of soundscape. The results showed that noise annoyance in the gated community was significantly lower than in the open community, although the noise level was of no significance between the two communities. The community planning mode moderated the relationships among the soundscape perception parameters between the gated and open communities. To reduce noise annoyance in the gated communities, each sound source should be considered; in open communities, traffic noise only should be considered. In a gated community, adding natural sounds to reduce noise annoyance may be a feasible intervention; in an open community, this is not necessary. Besides, there was no relationship between noise annoyance and Eventfulness in an open community, indicating that noise annoyance was insufficient to explain the complex sound environment of the community. China’s community planning will gradually shift from a gated community to an open community, making the soundscape of outdoor activity spaces likely to change dramatically in the future. The findings will help urban designers and managers to adopt targeted strategies to improve the soundscape and quality of life of community-dwelling older adults and children.

Effect of tonal noise and task difficulty on electroencephalography and cognitive performance

Objectives. The present study aimed to investigate the effect of tonal noise and task difficulty on electroencephalography (EEG) and cognitive performance. Methods. Twelve healthy volunteers participated in the present study. Four noise signals were generated by four prominence tone levels (0, 2, 5 and 9) at background noise levels of 55 dBA and frequency of 500 Hz using the Test Tone Generator from Esser Audio (USA). The participants were asked to perform the tasks with low, moderate and high levels of difficulty while exposed to the noises in an acoustics laboratory. The values of reaction time, correct rate and missed numbers were recorded during each step. Moreover, the EEG signals were measured. Results. The results showed that higher tone level and more task difficulty significantly decreased the correct rate, and increased the miss numbers. However, no significant effect was observed on reaction times. Furthermore, tone level and task difficulty significantly increased activity of the θ and β bands and decreased activity of the α band. Conclusion. Task difficulty and tone level could significantly affect the parameters of performance and the activity of EEG bands. Therefore, noise control can help sustain appropriate performance.

Wearable Devices in Health Monitoring from the Environmental towards Multiple Domains: A Survey

The World Health Organization (WHO) recognizes the environmental, behavioral, physiological, and psychological domains that impact adversely human health, well-being, and quality of life (QoL) in general. The environmental domain has significant interaction with the others. With respect to proactive and personalized medicine and the Internet of medical things (IoMT), wearables are most important for continuous health monitoring. In this work, we analyze wearables in healthcare from a perspective of innovation by categorizing them according to the four domains. Furthermore, we consider the mode of wearability, costs, and prolonged monitoring. We identify features and investigate the wearable devices in the terms of sampling rate, resolution, data usage (propagation), and data transmission. We also investigate applications of wearable devices. Web of Science, Scopus, PubMed, IEEE Xplore, and ACM Library delivered wearables that we require to monitor at least one environmental parameter, e.g., a pollutant. According to the number of domains, from which the wearables record data, we identify groups: G1, environmental parameters only; G2, environmental and behavioral parameters; G3, environmental, behavioral, and physiological parameters; and G4 parameters from all domains. In total, we included 53 devices of which 35, 9, 9, and 0 belong to G1, G2, G3, and G4, respectively. Furthermore, 32, 11, 7, and 5 wearables are applied in general health and well-being monitoring, specific diagnostics, disease management, and non-medical. We further propose customized and quantified output for future wearables from both, the perspectives of users, as well as physicians. Our study shows a shift of wearable devices towards disease management and particular applications. It also indicates the significant role of wearables in proactive healthcare, having capability of creating big data and linking to external healthcare systems for real-time monitoring and care delivery at the point of perception.

Exposure to the road traffic noise in an urban complex in Greece: the quantification of healthy life years lost due to noise-induced annoyance and noise-induced sleep disturbances

In the recent years, the environmental noise is a global issue of great concern. Especially, it is considered to be one of the most deleterious environmental risk factors for the human health and well-being in urban areas. In this study, we focus on the major source of the transportation noise in the modern-day urbanized societies, which is the road traffic noise. The study was performed in the urban complex in Thessaloniki-Neapoli in Greece, and the estimation of the road traffic noise levels was based on the CoRTN (Calculation of Road Traffic Noise) prediction method. In addition, we estimated the EBD (environmental burden of disease), in terms of DALYs (disability-adjusted life years), due to the annoyance and sleep disturbances associated with the exposure to road traffic noise. The estimation of the EBD was based on the strategic noise mapping in Thessaloniki-Neapoli as well as on the guidance document produced by the WHO (World Health Organization) for the quantitative assessment on the humans' health consequences of the environmental noise. Above all, the results revealed the magnitude of the health damage caused by the transportation noise.

Proposed Options for Noise Reduction from a Wastewater Treatment Plant: Case Study

Industry and industrial complexes are often located in the proximity of people’s homes. One of the negative effects of industry is noise emissions into the surrounding environment. With the increasing concentration of the human population and the increase in industrial production, more and more people are exposed to the negative effects of noise. This article discusses a comprehensive approach to reducing noise emissions from industrial operations, and the subsequent impacts on surrounding villages and human health. The first step of the whole process is to understand the current state of the acoustic situation in industrial operation and in the nearby villages, an important part of which is the identification and localization of dominant noise sources. For this purpose, a unique noise visualization tool was used, namely, an acoustic camera. The next important step is to propose a technical solution and measures to reduce the noise of the individual source. Consequently, it is necessary to create a mathematical model, i.e., noise maps, in order to verify whether the proposed measures will be sufficient. Once the proposed measures have been implemented, verification of the effectiveness of these measures needs to be carried out through repeated noise measurements in nearby villages and also on the site of the industrial installation. The above procedure was applied to the operation of a wastewater treatment plant that was causing noise exceeding the permissible levels in the surrounding villages. The application of this approach, the implementation of the proposed measures, and the subsequent verification confirmed a significant reduction in the noise levels in the affected villages, and the measures implemented were assessed as highly effective.

Quantitative proteomic analysis of cortex in the depressive-like behavior of rats induced by the simulated complex space environment

Long-term spaceflight has always been challenging for astronauts due to the extremely complicated space environmental conditions, including microgravity, noise, confinement, and circadian rhythms disorders, which may cause adverse effects on astronauts' mental health, such as anxiety and depression. Unfortunately, so far, the underlying mechanism is not fully understood. Hence, a novel type of box and rat cage was designed and built in order to simulate complex space environment on the ground. After earth-based simulation for 21 days, the rats exhibited the depressive-like behavior according to the sucrose preference and forced swimming test. We applied label-free quantitative proteomics to explore the molecular mechanisms of depressive-like behavior through global changes in cortical protein abundance, given that the cortex is the hub of emotional management. The results revealed up-regulated spliceosome proteins in contrast to down-regulated oxidative phosphorylation (OXPHOS), glutamatergic, and GABAergic synapse related proteins in the simulated complex space environment (SCSE) group. Furthermore, PSD-95 protein was found down-regulated in mass spectrometry, reflecting its role in the psychopathology of depression, which was further validated by Western blotting. These findings provide valuable information to better understand the mechanisms of depressive-like behavior. SIGNIFICANCE: Quantitative proteomic analysis can quantify differentially abundant proteins related to a variety of potential signaling pathways in the rat cortex in the simulated complex space environment. These findings not only provide valuable information to better understand the mechanisms of depressive-like behavior, but also might offer the potential targets and develop countermeasures for the mental disorders to maintain the health of astronauts during the long-term spaceflight.

Noise in Otolaryngology - Head and Neck Surgery operating rooms: a systematic review

OBJECTIVE

Noise in operating rooms (OR) can have negative effects on both patients and surgical care workers. Noise can also impact surgical performance, team communication, and patient outcomes. Such implications of noise have been studied in orthopedics, neurosurgery, and urology. High noise levels have also been demonstrated in Otolaryngology-Head and Neck Surgery (OHNS) procedures. Despite this, no previous study has amalgamated the data on noise across all OHNS ORs to determine how much noise is present during OHNS surgeries. This study aims to review all the literature on noise associated with OHNS ORs and procedures.

METHODS

Ovid Medline, EMBASE Classic, Pubmed, SCOPUS and Cochrane databases were searched following PRISMA guidelines. Data was collected on noise measurement location and surgery type. Descriptive results and statistical analysis were completed using Stata.

RESULTS

This search identified 2914 articles. Final inclusion consisted of 22 studies. The majority of articles analyzed noise level exposures during mastoid surgery (18/22, 82%). The maximum noise level across all OHNS ORs and OHNS cadaver studies were 95.5 a-weighted decibels (dBA) and 106.6 c-weighted decibels (dBC), respectively (P = 0.2068). The mean noise level across all studies was significantly higher in OHNS cadaver labs (96.9 dBA) compared to OHNS ORs (70.1 dBA) (P = 0.0038). When analyzed together, the mean noise levels were 84.9 dBA.

CONCLUSIONS

This systematic review demonstrates that noise exposure in OHNS surgery exceeds safety thresholds. Further research is needed to understand how noise may affect team communication, surgical performance and patient outcomes in OHNS ORs.

Classification of Noise Sources for Port Area Noise Mapping

Maritime transportation is recognized to have advantages in terms of environmental impact compared to other forms of transportation. However, an increment in traffic volumes will also produce an increase in noise emissions in the surroundings for a greener source, as ports are frequently surrounded by urban areas. When more sources or higher noise emissions are introduced, the noise exposure of citizens increases, and the likelihood of official complaints rises. As a consequence, among the most demanding aspects of port management is effective noise management aimed at a reduction in the exposure of citizens while ensuring the growth of maritime traffic. At the same time, the topic has not been thoroughly studied by the scientific community, mostly because port areas are challenging from a noise management point of view; they are often characterized by a high degree of complexity, both in terms of the number of different noise sources and their interaction with the other main transportation infrastructure. Therefore, an effective methodology of noise modeling of the port area is currently missing. With regard to the INTERREG Maritime Program, the present paper reports a first attempt to define noise mapping guidelines. On the basis of the current state-of-the-art and the authors’ experiences, noise sources inside port areas can be divided into several different categories: road sources, railway sources, ship sources, port sources, and industrial sources. A further subdivision can be achieved according to the working operation mode and position of the sources. This classification simplifies actions of identification of the responsible source from control bodies, in the case that noise limits are exceeded or citizen complaints arise. It also represents a necessary tool to identify the best placing of medium/long-term noise monitoring stations. The results also act as a base for a future definition of specific and targeted procedures for the acoustic characterization of port noise sources.

Biometric Data as Real-Time Measure of Physiological Reactions to Environmental Stimuli in the Built Environment

The physiological and cognitive effects of environmental stimuli from the built environment on humans have been studied for more than a century, over short time frames in terms of comfort, and over long-time frames in terms of health and wellbeing. The strong interdependence of objective and subjective factors in these fields of study has traditionally involved the necessity to rely on a number of qualitative sources of information, as self-report variables, which however, raise criticisms concerning their reliability and precision. Recent advancements in sensing technology and data processing methodologies have strongly contributed towards a renewed interest in biometric data as a potential high-precision tool to study the physiological effects of selected stimuli on humans using more objective and real-time measures. Within this context, this review reports on a broader spectrum of available and advanced biosensing techniques used in the fields of building engineering, human physiology, neurology, and psychology. The interaction and interdependence between (i) indoor environmental parameters and (ii) biosignals identifying human physiological response to the environmental stressors are systematically explored. Online databases ScienceDirect, Scopus, MDPI and ResearchGate were scanned to gather all relevant publications in the last 20 years, identifying and listing tools and methods of biometric data collection, assessing the potentials and drawbacks of the most relevant techniques. The review aims to support the introduction of biomedical signals as a tool for understanding the physiological aspects of indoor comfort in the view of achieving an improved balance between human resilience and building resilience, addressing human indoor health as well as energetic and environmental building performance.

Associations between road traffic noise exposure at home and school and ADHD in school-aged children: the TRAILS study

Environmental noise may play a role in the manifestation and severity of attention deficit/hyperactivity disorder (ADHD) symptoms, but evidence is limited. We investigated the cross-sectional associations between residential and school road traffic noise exposure and ADHD symptoms and diagnosis. The sample included n = 1710, 10-12-year-old children from the TRAILS study in The Netherlands. ADHD symptoms were measured using a DSM-IV based subscale from the Child Behavior Checklist. Children with diagnosed ADHD originated from the clinic-referred cohort. Road traffic noise (L_den) was estimated at the residence and school level, by model calculation. Risk ratios for ADHD symptoms and ADHD diagnoses, and regression coefficients for symptom severity were estimated separately and simultaneously for residential and school road traffic noise. Adjusted multinomial models with residential road traffic noise showed that residential noise was not associated with ADHD symptoms, but was associated with lower risks for ADHD diagnosis (RR = 0.93; 95% CI 0.89, 0.97). Similar associations were observed for models including school road traffic noise and models including both exposures. No clear exposure response relationship was observed for associations between residential or school noise and ADHD symptom severity. We found no evidence for a harmful association between road traffic noise and ADHD. Associations between noise and lower risks for ADHD were observed only in referred cases with a confirmed ADHD diagnosis and may be due to residual confounding or selection bias. Future studies should focus on residential and school noise exposure, and study associations with ADHD symptoms and diagnosis over time.

Ecological Validity of Immersive Virtual Reality (IVR) Techniques for the Perception of Urban Sound Environments

Immersive Virtual Reality (IVR) is a simulated technology used to deliver multisensory information to people under different environmental conditions. When IVR is generally applied in urban planning and soundscape research, it reveals attractive possibilities for the assessment of urban sound environments with higher immersion for human participation. In virtual sound environments, various topics and measures are designed to collect subjective responses from participants under simulated laboratory conditions. Soundscape or noise assessment studies during virtual experiences adopt an evaluation approach similar to in situ methods. This paper aims to review the approaches that are utilized to assess the ecological validity of IVR for the perception of urban sound environments and the necessary technologies during audio–visual reproduction to establish a dynamic IVR experience that ensures ecological validity. The review shows that, through the use of laboratory tests including subjective response surveys, cognitive performance tests and physiological responses, the ecological validity of IVR can be assessed for the perception of urban sound environments. The reproduction system with head-tracking functions synchronizing spatial audio and visual stimuli (e.g., head-mounted displays (HMDs) with first-order Ambisonics (FOA)-tracked binaural playback) represents the prevailing trend to achieve high ecological validity. These studies potentially contribute to the outcomes of a normalized evaluation framework for subjective soundscape and noise assessments in virtual environments.

Associations and effect modification between transportation noise, self-reported response to noise and the wider determinants of health: A narrative synthesis of the literature

Noise and health guidance to date have focused on the direct links between noise and health outcomes such as annoyance, sleep disturbance, cardiovascular and metabolic disease, and cognitive impairment in schoolchildren. However, noise is a psychosocial stressor, and there are individual studies showing that exposure to noise or the self-reported responses to noise may affect health through interactions with the wider determinants of health and well-being including physical activity, use of green spaces and social interactions. Despite this emerging evidence concerning potential impacts of noise on the wider determinants of health, literature in the field remains dispersed and unsynthesised. This study seeks to synthetize evidence on different relationships between transportation noise, self-reported responses to noise and the wider determinants of health using a systematic review methodology. The search was conducted in Medline, PsycINFO, PubMed, and Scopus on articles published from 2000 to 2017. This led to the review of 76 papers which satisfied the inclusion criteria. Despite strong heterogeneity in the studies' methodologies and indicators used, there is some evidence that noise exposure and responses to noise such as annoyance and disturbance are associated with people's lifestyle, recreational activities as well as the local economy of the neighbourhood. On the other hand, there are some wider determinants of health, mainly those related to the built and natural environment, which modify the relationship between noise exposure and self-reported responses to noise. In particular, greenness, having access to quiet areas, and covering noise sources either visually or acoustically with natural features seems to decrease people's negative responses to noise. Results indicate that transportation noise has the potential to affect health through various pathways, and a holistic approach is needed to capture all the effects.

Occupational Noise: Auditory and Non-Auditory Consequences

Occupational noise exposure accounts for approximately 16% of all disabling hearing losses, but the true value and societal costs may be grossly underestimated because current regulations only identify hearing impairments in the workplace if exposures result in audiometric threshold shifts within a limited frequency region. Research over the past several decades indicates that occupational noise exposures can cause other serious auditory deficits such as tinnitus, hyperacusis, extended high-frequency hearing loss, and poor speech perception in noise. Beyond the audiogram, there is growing awareness that hearing loss is a significant risk factor for other debilitating and potentially life-threatening disorders such as cardiovascular disease and dementia. This review discusses some of the shortcomings and limitations of current noise regulations in the United States and Europe.

Level-set based topology optimization on acoustic balcony ceiling design of a simplified urban building for noise reduction

Balconies can provide noise shielding for residents who live in high-rise apartment buildings. The efficiency of noise reduction induced by a balcony largely depends on the shape of the balcony ceiling. This study aims to optimize the shape of the ceiling of a two-dimensional simplified urban building to enhance noise mitigation by using level-set based topology optimization, which is capable of providing a distinct and smooth interface. Noise sources at both single and multi-frequency optimization are considered. In the single-frequency optimization, two peak frequencies in the spectrum of sound pressure level (SPL) at receivers on the fourth floor of an ordinary ceiling are selected. Results show that significant SPL reduction is attained by the optimized ceiling. In addition, broadband noise suppression at frequencies above the target value is also achieved. The underlying mechanism is that the optimized ceiling consisting of several concaves can redirect the incident wave propagating away from the balcony and effectively avoid forming a trapped mode within the area between the floor and the ceiling. Additionally, more effective noise reduction is achieved by the multi-frequency optimization. Thus, the proposed design strategy can be widely used in various applications of noise reduction in the field of building and environment.

Ultra-broadband local active noise control with remote acoustic sensing

One enduring challenge for controlling high frequency sound in local active noise control (ANC) systems is to obtain the acoustic signal at the specific location to be controlled. In some applications such as in ANC headrest systems, it is not practical to install error microphones in a person’s ears to provide the user a quiet or optimally acoustically controlled environment. Many virtual error sensing approaches have been proposed to estimate the acoustic signal remotely with the current state-of-the-art method using an array of four microphones and a head tracking system to yield sound reduction up to 1 kHz for a single sound source. In the work reported in this paper, a novel approach of incorporating remote acoustic sensing using a laser Doppler vibrometer into an ANC headrest system is investigated. In this “virtual ANC headphone” system, a lightweight retro-reflective membrane pick-up is mounted in each synthetic ear of a head and torso simulator to determine the sound in the ear in real-time with minimal invasiveness. The membrane design and the effects of its location on the system performance are explored, the noise spectra in the ears without and with ANC for a variety of relevant primary sound fields are reported, and the performance of the system during head movements is demonstrated. The test results show that at least 10 dB sound attenuation can be realised in the ears over an extended frequency range (from 500 Hz to 6 kHz) under a complex sound field and for several common types of synthesised environmental noise, even in the presence of head motion.

Geographic Ecological Momentary Assessment (GEMA) of environmental noise annoyance: the influence of activity context and the daily acoustic environment

Background

Noise annoyance is considered to be the most widespread and recognized health effect of environmental noise. Previous research is mostly based on the static study of residential environmental noise, but few studies have focused on the effects of noise exposure in different activity contexts on real-time annoyance. The two deficiency are that they neglect the influence of activity context besides residence and fail to reflect the difference of time-scale effect of noise influence.

Methods

Using portable noise and air sensors, GPS-equipped mobile phones, questionnaire survey, and geographic ecological momentary assessment (GEMA), this paper measured the environmental noise and real-time noise annoyance of participants at different activity places. Hierarchical logistic regression models were used to examine the effects of environmental noise on people’s real-time annoyance. The paper further considered the influence of the geographic context of the activity places and daily acoustic environment on participants’ real-time annoyance. Further, a nonlinear regression model was constructed using Random Forest to further examine the nonlinear relationship between environmental noise and real-time annoyance.

Results

The results showed that: (1) the average cumulative equivalent sound level during was 55 dB (A) when the participants responded to the EMA surveys; (2) Only the temperature of activity places had an influence on momentary annoyance and the higher the temperature, the more likely participants were annoyed; (3) Participants with higher perception of noise pollution in residential communities were more likely to be annoyed. However, participants with higher daily exposure to noise were less likely to feel annoyed; (4) The threshold value of the effect of noise on real-time annoyance was 58 dB (A) to 78 dB (A).

Conclusions

These findings can guide the development of urban planning and environmental noise standards and also provide a reference for noise barrier requirements for different activity places.

Impact of Alarm Fatigue on the Work of Nurses in an Intensive Care Environment-A Systematic Review

Background: In conditions of intensive therapy, where the patients treated are in a critical condition, alarms are omnipresent. Nurses, as they spend most of their time with patients, monitoring their condition 24 h, are particularly exposed to so-called alarm fatigue. The purpose of this study is to review the literature available on the perception of clinical alarms by nursing personnel and its impact on work in the ICU environment. Methods: A systematic review of the literature was carried out according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol. The content of electronic databases was searched through, i.e., PubMed, OVID, EBSCO, ProQuest Nursery, and Cochrane Library. The keywords used in the search included: “intensive care unit,” “nurse,” “alarm fatigue,” “workload,” and “clinical alarm.” The review also covered studies carried out among nurses employed at an adult intensive care unit. Finally, seven publications were taken into consideration. Data were analyzed both descriptively and quantitatively, calculating a weighted average for specific synthetized data. Results: In the analyzed studies, 389 nurses were tested, working in different intensive care units. Two studies were based on a quality model, while the other five described the problem of alarms in terms of quantity, based on the HTF (Healthcare Technology Foundation) questionnaire. Intensive care nurses think that alarms are burdensome and too frequent, interfering with caring for patients and causing reduced trust in alarm systems. They feel overburdened with an excessive amount of duties and a continuous wave of alarms. Having to operate modern equipment, which is becoming more and more advanced, takes time that nurses would prefer to dedicate to their patients. There is no clear system for managing the alarms of monitoring devices. Conclusion: Alarm fatigue may have serious consequences, both for patients and for nursing personnel. It is necessary to introduce a strategy of alarm management and for measuring the alarm fatigue level.

Dynamic Evaluation of Traffic Noise through Standard and Multifractal Models

Traffic microsimulation models use the movement of individual driver-vehicle-units (DVUs) and their interactions, which allows a detailed estimation of the traffic noise using Common Noise Assessment Methods (CNOSSOS). The Dynamic Traffic Noise Assessment (DTNA) methodology is applied to real traffic situations, then compared to on-field noise levels from measurement campaigns. This makes it possible to determine the influence of certain local traffic factors on the evaluation of noise. The pattern of distribution of vehicles along the avenue is related to the logic of traffic light control. The analysis of the inter-cycles noise variability during the simulation and measurement time shows no influence from local factors on the prediction of the dynamic traffic noise assessment tool based on CNOSSOS. A multifractal approach of acoustic waves propagation and the source behaviors in the traffic area are implemented. The novelty of the approach also comes from the multifractal model’s freedom which allows the simulation, through the fractality degree, of various behaviors of the acoustic waves. The mathematical backbone of the model is developed on Cayley–Klein-type absolute geometries, implying harmonic mappings between the usual space and the Lobacevsky plane in a Poincaré metric. The isomorphism of two groups of SL(2R) type showcases joint invariant functions that allow associations of pulsations–velocities manifolds type.

Aircraft noise control policy and mental health: a natural experiment based on the Longitudinal Aging Study Amsterdam (LASA)

Background

This study examines the impact of environmental noise policy on depressive symptoms by exploiting the national experiment afforded by the New Deal aircraft noise control policy introduced in Schiphol (Amsterdam) in 2008.

Methods

Data came from older adults (ages 57–102) participating in three waves (2005/2006, 2008/2009 and 2011/2012) of the Longitudinal Aging Study Amsterdam (LASA) (N=1746). Aircraft noise data from the Netherlands Environmental Assessment Agency were linked to LASA cohort addresses using the GeoDMS software. The Centre for Epidemiologic Studies—Depression (CES-D) scale was used to measure depressive symptoms. Using a difference-in-dfferences (DiD) approach, we compared changes in CES-D levels of depressive symptoms before and after the policy between people living close (≤15 km) and those living far away (>15 km) from Schiphol airport.

Results

There were few changes in noise levels after the introduction of the policy. Estimates suggested that the policy did not lead to a reduction in noise levels in the treatment areas relative to the control areas (DiD estimate=0.916 dB(A), SE=0.345), and it had no significant impact on levels of depressive symptoms (DiD estimate=0.044, SE=0.704). Results were robust to applying different distance thresholds.

Conclusion

The New Deal aircraft noise control policy introduced in Amsterdam was not effective in reducing aircraft noise levels and had no impact on depressive symptoms in older people. Our results raise questions about the effectiveness of the current noise control policy to improve the well-being of residents living near the airport.

How paramedics perceive internal noise in ambulance? sensory processing sensitivity (SPS) and Subjective Noise Assessment

Introduction:

This article discusses the correlation between sensory processing sensitivity (SPS) as a feature of personality and temperament and paramedics’ subjective perception of noise inside an ambulance. Description of the theoretical basis of SPS has been strongly depicted.

Materials and methods:

Polish translation of SPS 12-item short scale and a survey concerning the subjective perception of noise inside an ambulance have been used in this research. Assessment of noise included its three sources: emergency vehicle siren, resistance of rolling tires and noise produced by diesel engines. 46 paramedics from mobile emergency care units working in Poznan and the Poznan’s district have taken part in the research. Paramedics with higher SPS results were selected, creating a highly sensitive people (HSP) group.

Results:

When non-HSP people were compared to paramedics from the HSP group, an emergency signal was considered more burdensome for HSP paramedics. The intensity of noise generated by the vehicle’s suspension elements and tires was significantly higher in cars more than 3 years old. Older paramedics (≥30 years old) evaluated the intensity as well as burdensomeness of noise generated by suspension’s elements and tires, higher than the younger (<30 years old) ones.

Conclusions:

Both paramedics and drivers as occupational groups are liable to noise, which seems to be particularly harmful and burdensome to the HSP group. Further studies should be provided in this area. This may lead to an increase not only in their productivity but also in their quality of life.

Carbon Nanomaterials: A New Sustainable Solution to Reduce the Emerging Environmental Pollution of Turbomachinery Noise and Vibration

The vibration and noise that resulted from turbomachinery, such as fans, compressors, and centrifugal pumps, are known to bring considerable disturbance and pollution to the machine itself, the environment, and the operators. Hence, how to cope with the vibration and noise has become a recent research focus. With the advancement of materials science, more and more new nanomaterials have been applied in the field of noise and vibration reduction. To be specific, carbon-based nanomaterials, such as carbon fibers, carbon nanotubes, and graphenes, have achieved outstanding results. Carbon nanocomposites, such as carbon nanofibers, carbon nanotubes, and graphenes, are characterized by their low densities, high strengths, and high elastic moduli, all of which made carbon nanocomposites the most promising vibration and noise-reduction composites, thanks to their damping properties, compatibilities, noise and vibration absorption qualities, and wide wave-absorbing frequency bands. In light of this, this paper summarizes the progresses and application prospects of such carbon nanocomposites as carbon nanofibers, carbon nanotubes, and graphenes in the field of turbomachinery vibration and noise reduction.

Subjective criteria underlying noise-tolerance in the presence of speech

OBJECTIVE

The objective was to determine the relative contribution of four criteria (loudness, annoyance, distraction, speech interference) to participants' noise-tolerance thresholds (NTT).

DESIGN

While listening to speech in noise set at the highest signal-to-noise ratio at which noise became unacceptable (noise tolerance threshold), participants completed paired-comparison judgments of loudness, annoyance, distraction, and speech interference to determine the noise domain(s) that were most important in their noise tolerance judgments. Participants also completed absolute ratings of the noise using the same noise domains, which were combined with the paired comparison data for analysis.

STUDY SAMPLE

Sixty-three adults with normal hearing participated.

RESULTS

For the entire group, speech interference and distraction were the largest contributors to noise tolerance. A cluster analysis indicated three distinct groups: criteria were dominated by either annoyance (33%); distraction (48%), or speech interference (19%). Significant differences in NTT among the groups revealed the highest mean NTT for the annoyance group and lowest NTT for the speech interference group.

CONCLUSION

The majority of participants based NTTs on criteria related to the noise itself (annoyance or distraction) and had greater noise sensitivity than the smaller group of participants who focused more on speech intelligibility in the noise.

How do Rural Second Homes Affect Human Health and Well-being? Review of Potential Impacts

Contact with nature is associated with numerous psychological, physiological and social health and well-being benefits. Outdoor recreation, such as rural second home tourism, provides extensive exposure to the natural environment, but research around health impacts of this exposure is scattered. We review current research on health and well-being impacts of nature and discuss how the characteristics of rural second home environments and their use and users can affect these potential impacts in Finland. We discover four key issues affecting the impacts. First, health and well-being impacts depend on the users; urban people can especially benefit from rural second homes, while child development and the performance of elderly people can also be supported by contact with nature at second homes. Second, the regularity, length and season of second home visits influence the potential to receive benefits as they have an impact on the intensity of nature exposure. Third, the type and quality of second home environment affect contact with nature, such as exposure to health-supporting environmental microbes. Fourth, practices, motives and meanings modify activities and attachment and crucially affect both physical and mental well-being. We conclude that rural second homes have extensive potential to provide nature-related health and well-being benefits and further research is needed.

Evaluation of practical framework for industrial noise mapping: A case study

Strategic noise maps are typically prepared for large-scale areas, towns and cities. However, some comparatively smaller industries are given less importance during preparation of noise maps. Very few studies have been reported worldwide providing insight on industrial noise mapping, and similar reports from India are negligible. This study provides a noise map of a forging plant and also investigates noise distribution pattern within 2 km of surrounding area. The complete study is evaluated in two types of scenario; in the first scenario all individual noise sources of the plant were considered as point sources whereas in the second scenario complete plant was treated as an area source. Furthermore, a regression graph is generated between the predicted and measured values for both scenarios individually which gives coefficients of determination of 0.4689 and 0.6382. This study reveals that the second scenario provides more precise noise prediction map than the first scenario.

Supplementation of Taurine Insulates Against Oxidative Stress, Confers Neuroprotection and Attenuates Memory Impairment in Noise Stress Exposed Male Wistar Rats

Noise has always been an important environmental factor that induces health problems in the general population. Due to ever increasing noise pollution, humans are facing multiple auditory and non-auditory problems including neuropsychiatric disorders. In modern day life it is impossible to avoid noise due to the rapid industrialization of society. Continuous exposure to noise stress creates a disturbance in brain function which may lead to memory disorder. Therefore, it is necessary to find preventive measures to reduce the deleterious effects of noise exposure. Supplementation of taurine, a semi essential amino acid, is reported to alleviate psychiatric disorders. In this study noise-exposed (100 db; 3 h daily for 15 days) rats were supplemented with taurine at a dose of 100 mg/kg for 15 days. Spatial and recognition memory was assessed using the Morris water maze and novel object recognition task, respectively. Results of this study showed a reversal of noise-induced memory impairment in rats. The derangements of catecholaminergic and serotonergic levels in the hippocampus and altered brain antioxidant enzyme activity due to noise exposure were also restored by taurine administration. This study highlights the importance of taurine supplementation to mitigate noise-induced impaired memory via normalizing the neurochemical functions and reducing oxidative stress in rat brain.

Citizen scientists and university students monitor noise pollution in cities and protected areas with smartphones

Noise pollution can cause increased stress, cognitive impairment and illness in humans and decreased fitness and altered behavior in wildlife. Maps of noise pollution are used to visualize the distribution of noise across a landscape. These maps are typically created by taking a relatively small number of sound measurements or simulated on the basis of theoretical models. However, smartphones with inexpensive sound measuring apps can be used to monitor noise and create dense maps of real-world noise measurements. Public concern with noise can make monitoring noise pollution with smartphones an engaging and educational citizen science activity. We demonstrate a method utilizing single-day citizen science noise mapping events and a university lab to collect noise data in urban environments and protected areas. Using this approach, we collected hundreds of noise measurements with participants that we used to create noise maps. We found this method was successful in engaging volunteers and students and producing usable noise data. The described methodology has potential applications for biological research, citizen science engagement, and teaching.

The role of depressive symptoms within the association of long-term exposure to indoor and outdoor traffic noise and cognitive function - Results from the Heinz Nixdorf Recall study

OBJECTIVES

Traffic noise is negatively associated with cognitive function, and its perception can differ between depressed and non-depressed people. We studied the role of depressive symptoms in the association between traffic noise and cognitive function. We studied the role of depressive symptoms in the association between traffic noise and cognitive function.

METHODS

During the first follow-up examination (2006-2008) of the German Heinz Nixdorf Recall study, cognitive function (five subtests and an additive global summary score, GCS) and depressive symptoms (CES-D score) were assessed in 2745 participants (aged 50-80, 49.8% women). Mild cognitive impairment (MCI) was diagnosed according to the Petersen criteria in 380 participants. Long-term exposure to traffic noise was modeled as weighted 24-h mean (L_DEN) and night-time mean (L_NIGHT) at the façade of the baseline addresses, and was corrected for indoors (L_{DEN_IN} and L_{NIGHT_IN}). We developed multiple linear and logistic regression models adjusted for individual-level characteristics to investigate cross-sectionally the role of depressive symptoms in the association of traffic noise with cognitive function.

RESULTS

Overall, 8.6% participants had depressive symptoms. The median noise values were L_DEN 52.1 dB(A) and L_{DEN_IN} 34.7 dB(A). Associations were slightly stronger for cognitive subtests in those with severe depression (CES-D>21), i.e., per 10 dB(A) L_DEN and verbal fluency: β = -0.04 [-0.11; 0.03] for CES-D≤21 and β = -0.09 [-0.24; -0.06] for CES-D>21. Additional adjustment of the main model for CES-D did not change the association between noise and cognitive outcomes. Estimates using indoor noise exposure were generally stronger and more precise.

CONCLUSIONS

Depressed people may be more susceptible to adverse effects of noise than non-depressed. Modeled estimates of indoor noise exposure is possibly a more appropriate measure of exposure.

Cyclists' noise exposure in a Brazilian medium-sized city

This study aimed to assess cyclists' exposure to noise in a medium-sized Brazilian city. Mobile sensors were used to conduct noise measurements in streets with and without dedicated cycling infrastructures. The method can be summarized in the following procedures: i) characterization of the study area; ii) data collection and validation; iii) calculation of exposure indicators; and iv) comparison and representation of the results on maps. Two strategies were adopted for the analysis, namely, spatial data aggregation and temporal data aggregation. Thus, measurements were initially organized in 1,200 nodes distributed along the paths. The results indicate that bicycle riders in São Carlos may be exposed, in some routes, to a high proportion of high noise-level segments. In the two routes selected for this study, the cyclist was exposed to noise levels above the adopted threshold (> 75dBA) in 33.2% and 18.9% of the nodes. Also, the possibility of simultaneously working with two related indicators has broadened the classification criteria of the route segments regarding noise exposure.

Male/female Differences in Radial Arm Water Maze Execution After Chronic Exposure to Noise

Introduction:

Noise is one of the main sources of discomfort in modern societies. It affects physiology, behavior, and cognition of exposed subjects. Although the effects of noise on cognition are well known, gender role in noise-cognition relationship remains controversial.

Aim:

We analyzed the effects of noise on the ability of male and female rats to execute the Radial Arm Water Maze (RAWM) paradigm.

Materials and Methods:

Male and female Wistar rats were exposed to noise for 3 weeks, and the cognitive effects were assessed at the end of the exposure. RAWM execution included a three-day training phase and a reversal-learning phase conducted on the fourth day. Escape latency, reference memory errors, and working memory errors were quantified and compared between exposed and non-exposed subjects.

Results:

We found that male rats were in general more affected by noise. Execution during the three-day learning phase evidenced that male exposed rats employed significantly more time to acquire the task than the non-exposed. On the other hand, the exposed females solved the paradigm in latencies similar to control rats. Both, males and females diminished their capacity to execute on the fourth day when re-learning abilities were tested.

Conclusion:

We conclude that male rats might be less tolerable to noise compared to female ones and that spatial learning may be a cognitive function comparably more vulnerable to noise.

Assessment of noise pollution and associated subjective health complaints and psychological symptoms: analysis through structure equation model

Road traffic noise is affecting the exposed population through its detrimental effects. This study was conducted in urban zones of Peshawar, Khyber Pakhtunkhwa, Pakistan, to analyze causal relationship between noise and subjective health complaints with a special focus on psychological symptoms. A 12-h (LAeq) noise survey conducted at different locations (n = 57) indicated a noise range of 46.3-86.3 dB (A). A questionnaire survey was conducted from local residents (n = 500), students (n = 500), policemen (n = 500), shopkeepers (n = 500), and drivers (n = 500) exposed to road traffic noise and analyzed through structure equation modeling (SEM). Different models were prepared and a modified model obtained the acceptable model fit, i.e., chi-square 0.093, χ²/df 1.286, comparative fit index 0.986, goodness of fit index 0.966, normed fit index 0.943, Tucker-Lewis index 0.977, and root mean square error of approximation 0.034. The modified model gives not only the information about direct but also indirect effects of noise on the exposed population. Adding on, the model clearly indicates that sensitivity to noise has strong relationship with subjective health complaints (headache, exhaustion, and psychological symptoms such as annoyance, difficulty concentrating, ill temper, and anxiety) than profession, age, location, and gender. Duration of exposure to road traffic noise has an important role in increasing the frequency of subjective health issues. The model is important in depicting that sensitivity to noise may produce subjective health complaints (standardized parameter estimates of 0.12 and 0.29) but the mediator has much stronger positive path estimates (0.59). The modified model sought to discover and explicate the underlying mechanism of an observed relationship existing between the selected dependent and an independent variable through the identification of the mediator variables.