Traffic Noise Pollution： Spectra Characteristics and Windows Sound Insulation in Laboratory and Field Measurements

The traffic spectra influence on indoor noise through windows is evaluated with laboratory and field measurements. Different traffic noise spectra were registered and reproduced, simulating the outdoor traffic conditions through different windows. Spectrum adaptation terms for the recorded spectra were different from the ones obtained from the Standards, showing that Normative gives a safe evaluation of the Weighted Sound Insulation Index. In field measurements, the level abatements calculated from the Facade Acoustic Insulation Index corrected with the adaptation terms shows that the ones from the Standard do not give a good approximation, while if the level abatements is calculated using the adaptation terms from the registered spectra, a more reliable approximation is achieved. Furthermore, comparing the level abatements for two windows having both Rw equal to 41 dB, very different values were obtained at different frequencies; therefore to characterize acoustic performances of windows, sound insulation curves are also needed. The correlation between the mean difference between adaptation terms calculated from the standard and the one between abatements obtained with pink noise and the ones obtained with the registered spectra is good, but different for road traffic and trains. In both, the difference diminishes when the difference between the abatements increases.

Assessment of health impacts of noise pollution in the Tarkwa Mining Community of Ghana using noise mapping techniques

Objective Communities in the developing countries such as Ghana have little knowledge of effects of noise pollution on human health,which is demonstrated by their attitude towards this menace.This study assessed the health impacts of noise pollution and its spatial distribution in the Tarkwa Mining Community(TMC)of Ghana.Methods To achieve the study objective,questionnaires were administered;as well as collation of health data from major health centers in the study area.Noise levels were measured and noise map produced using geographic information system(GIS)techniques.Overlay maps of some diseases were done using overlay techniques in GIS.The noise exposure and corresponding noise doses for churches,working sites and social centers were also calculated using the respective formulae.Results The noise levels were found to be high above the prescribed Ghana Environmental Protection Agency(EPA)standards,with traffic noise levels ranging from 65.00 dBA to 98 dBA,while that of churches ranged from 73.10 dBA to 107.00 dBA and that of working sites from 74.4 dBA to 115.2 dBA.The calculated noise exposure and corresponding noise dose for churches ranged from 75.1 dBA to 104.6 dBA(i.e.,10%‒8000%),while that for workers’sites were from 75.8 dBA to 115 dBA(i.e.,12%‒90000%).Statistical regression and correlation analyses were done for diseases such as hypertension,ear problems and sleep disturbances.Conclusion The study has therefore revealed that the noise levels in the study area are very high and corresponding health impacts are prominent.Stakeholders and authorities should devise mitigating measures to combat this rising menace.The results revealed a strong positive correlation between noise and corresponding health impacts.Despite the positive correlation there are other causes and effects to the mentioned diseases.

Assessment of Indoor and Outdoor Noise Pollution at a University Hospital Based on Acoustic Measurements and Noise Mapping

This paper describes an analysis of the sound pressure levels at the exterior façade and inside the Hospital de Clínicas of the Federal University of Paraná. Measurements were taken at a total of 45 points, 24 at the exterior facade and 21 points inside the hospital on all the floors of the main building and in the maternity building. These 45 measurements were used to calculate the acoustic map of the hospital, which is located on General Carneiro Street, in the city of Curitiba, state of Paraná, Brazil. A comparison of the measured outdoor sound pressure levels against those established by Curitiba Municipal Law No. 10625 revealed that they all exceeded the daytime limit of 55 dB(A) permitted for areas around hospitals. The indoor sound pressure measurements and the noise levels for acoustic comfort established by the Brazilian technical standard ABNT NBR 10152 were compared, indicating that all the measured points, including those in the neonatal intensive care unit, exceeded the established limit of 35 dB(A) to 45 dB(A).

Investigation on Noise Pollution Comprehensive Treatment of Distribution Transformer in Living Area

In the current paper,which deals with the noise pollution excited by distribution transformers in the living area,a comprehensive treatment scheme is put forward for the purpose of reducing the sound pressure level emitting into the environment.In accordance with the associated test standard,the sound pressure levels of distribution transformer and surrounding environment are not only tested but analyzed as well.The measurements were carried out with the frequency analysis of the 1/3 octave resolution,with the center frequencies at 125 Hz,250 Hz,400 Hz,and 500 Hz.As illustrated,on the basis of the measurement results,the frequency of noise at 500 Hz of distribution transformer causes the major noise pollution in the surrounding environment.This measurement result is in line with the noise frequency characteristics of distribution transformer.There are two transmission routes of noise:(i)the noise excited by distribution transformer transmits by means of the wall of distribution room,and (ii)part of noise spreads through the ground of distribution room.Accordingly,acoustic shield and vibration isolation device are applied for the reduction of the low frequency noise emitted through the above two paths.Aimed at applying the appropriate acoustic material and vibration mounting,the evaluation of the noise reduction and vibration absorption is carried out in accordance with the sound and vibration insulation theory.Following the noise treatment,the transformer and environment noise are measured again.The corresponding findings shed light on the fact that the sound level satisfied the requirement of limits of the ordinance.The proposed noise treatment scheme can be applied to the existing power distribution facilities for controlling the sound levels that reach a point where it is comparatively more unobjectionable.

Analysis of Road Traffic Noise Pollution around a University in Binzhou

The number of automobiles in the urban area of Binzhou City continues to increase,and traffic noise pollution is increasingly serious. In this study,noise pollution on Huanghe 5 Road near the south gate of Binzhou University was monitored. The results showed that the road noise pollution on Huanghe 5 Road was relatively serious on the whole,especially in the peak periods of traffic flow in the morning and afternoon,because the increase in the number of pedestrians brought inconvenience to traffic,thereby resulting in an increase in car whistle.

Effects of Noise Pollution on Functions of the Liver and Kidney of Rats

To study the effects of noise pollution on the functions of the liver and kidney of rats, a total of 40 male SPF Wistar rats were randomly divided into a control group and three experimental groups. The rats in the experimental groups were respectively stimulated with 38, 55 and 70 dB noise for 15 days, and the levels of blood components were determined by an automatic biochemical analyzer. The results showed that in compari-son with the control group, the level of the blood glucose in the experimental groups increased by 23.53%, 52.94% and 88.24%, respectively, and the differences were statistically significant （P〈0.01）. The levels of triglyceride in the blood rose by 20.83%, 38.54% and 79.68%, respectively, and the differences were also statistically significant （P〈0.01）. The level of globulin in the blood increased by 16.49%, 21.13% and 51.78%, and the level of albumin in the blood rose by 9.51 %, 12.67% and 17.89%, respectively. The level of total bilirubin in the blood increased by 27.04%, 41.63% and 73.67%, respectively, and the differences were statistically significant （P〈0.01）. The level of creatinine in the blood rose by 9.72%, 10.21% and 20.99%, respectively. The level of amylase in the blood reduced by 6.6%, 13.05% and 23.89%, respectively. The level of creatine kinase in the blood decreased by 19.81%, 27.37% and 36.81 %, respectively, and the level of urea in the blood reduced by 11.19%, 12.77% and 19.26%, respectively. The results revealed that noise pollution could significantly affect the levels of blood components and the functions of the liver and kidney of rats.

Evaluation of occupational noise pollution and attitudes of exposed workers in two metal industries

The purpose of the present study was to determined noise levels and to show the annoyance reaction, hearing loss, hearing impairment by the workers due to the occupational noise exposure according to Iran development of Environment （IDE） and also awareness about effects of noise and use of hearing protective devices （HPD） in the two manufacturing electronic equipment （metal） industries. The present study was carried out among industrial workers and included a sample of lao workers, site 1 （n = 52） and site 2 （n = 78） from two metal industries located in south eastern Iran province of Kerman. In order to attend the objectives of the current study, noise levels evaluation was determined throughout all different work stations in both industries. The results of the study revealed that noise levels in 75% of the stations are higher than limits used for assessment of noise for community response. The result of the study indicated that noise levels in the workplace are （66%） very high, （28%） high and only 6% low. Workers having higher education are much aware of the health impact due to occupational noise. Chi-square analysis indicated that the difference in educational background and not wearing HPD was significant and also a significant relationship was also observed between the impact of occupational noise on the health and education status. This research has clearly demonstrated that the workers in both the metal industries included in this study are at high risk of developing noise induced hearing loss and other associated ailments due to excessive occupational exposure to noise. There is a need to develop and apply a well-defined, comprehensive and enforceable training programs and noise regulation. The study revealed that the workers having higher education （9-12 grades） are much aware of the health impact due to occupational noise exposure. There is a need to establish a hearing conservation programs in both industries, the components of such program include noise assessment, use of hearing protection devices, audiometric and increasing awareness among the workers about the adverse effects of noise.

Quieting the neonatal intensive care unit:A quality improvement initiative

BACKGROUND The neonatal intensive care unit(NICU)is vital for preterm infants but is often plagued by harmful noise levels.Excessive noise,ranging from medical equipment to conversations,poses significant health risks,including hearing impairment and neurodevelopmental issues.The American Academy of Pediatrics recommends strict sound limits to safeguard neonatal well-being.Strategies such as education,environmental modifications,and quiet hours have shown to reduce noise levels.However,up to 60%of the noises remain avoidable.High noise exposure exacerbates physiological disturbances,impacting vital functions and long-term neurological outcomes.Effective noise reduction in the NICU is crucial for promoting optimal neonatal development.AIM To measure the sound levels in a NICU and reduce ambient sound levels by at least 10%from baseline.METHODS A quasi-experimental quality improvement project was conducted over 4 mo in a 20-bed level 3 NICU in a tertiary care medical college.Baseline noise levels were recorded continuously using a sound level meter.The interventions included targeted education,environmental modifications,and organizational changes,and were implemented through three rapid Plan-Do-Study-Act(PDSA)cycles.Weekly feedback and monitoring were conducted,and statistical process control charts were used for analysis.The mean noise values were compared using the paired t-test.RESULTS The baseline mean ambient noise level in the NICU was 67.8 dB,which decreased to 50.5 dB after the first cycle,and further decreased to 47.4 dB and 51.2 dB after subsequent cycles.The reduction in noise levels was 21%during the day and 28%PDSA cycle(mean difference of−17.3 dB,P<0.01).Peak noise levels decreased from 110 dB to 88.24 dB after the intervention.CONCLUSION A multifaceted intervention strategy reduced noise in the NICU by 25%over 4 months.The success of this initiative emphasizes the significance of comprehensive interventions for noise reduction.

Feed-Forward Active Noise Control System Using Microphone Array

Feedforward active noise control(ANC)system are widely used to reduce the wide-band noise in different application.In feedforward ANC systems,when the noise source is unknown,the misplacement of the reference microphone may violate the causality constraint.We present a performance analysis of the feedforward ANC system under a noncausal condition.The ANC system performance degrades when the degree of noncausality increases.This research applies the microphone array technique to feedforward ANC systems to solve the unknown noise source problem.The generalized cross-correlation(GCC)and steering response power(SRP)methods based on microphone array are used to estimate the noise source location.Then,the ANC system selects the proper reference microphone for a noise control algorithm.The simulation and experiment results show that the SRP method can estimate the noise source direction with 84%accuracy.The proposed microphone array integrated ANC system can dramatically improve the system performance.

Effects of geometric design of forest road and roadside vegetation on traffic noise reduction

Geometric design of forest roads and design of their landscapes can reduce noise pollution and its harmful effects on human health. We investigated the effects of technical and biological parameters such as geometric road design and various roadside tree stands on reducing noise pollution according to the tree density and distance from roadway in Darabkola Forests, Sari, Iran. We recorded the noise generated by a car （Land Rover） relative to changes in longitudinal slope, horizontal curve radius and type of road pavement. We also measured noise levels according to roadside tree density and stand type （coniferous and hardwood） in 40 rectangular plots of three widths （25, 100 and 300 m） and 50 m length that were randomly demar- cated along forest roads. The changes in noise level were recorded using a decibel meter with an accuracy of q-1.5 dB and resolution of 0.1 dB. Noise levels were higher alongside unpaved roads than alongside paved roads. There was an inverse relationship between the measured noise level and horizontal curve radius. The rate of noise level on horizontal curve with a radius less than 30, 30-45 m and more than 45 m were 64.8, 70.8 and 75.9 dB, respectively. The noise level increased with the increasing longitudinal slope of the road. There was a significant difference between the noise level on slopes less than 3 % （67 dB） and 3-8 % （71.2 dB） in comparison with slopes greater than 8 % （77.8 dB）, （p 〈 0.05）. Pinus brutia L. reduced the noise level more （about 6 dB） in stands of 1/3 density of mixed hardwoods within 25 m from middle of the road. Careful design of geometric properties of forest roads as well as planting coniferous trees with hardwoods is a suitable solution for reducing noise pollution.

Noisy environments:untangling the role of anthropogenic noise on bird species richness in a Neotropical city

Background:Among urban stimuli,anthropogenic noise has been identified to be one of the behavioral drivers of species that rely on acoustic signals for communication.Studies have shown both species‑specific and assemblage responses to urban noise,ranging from the modulation of their acoustic frequencies and spatiotemporal adjustments to declines in species richness.In this study,we assessed the citywide relationship between two anthropogenic noise variables(noise levels recorded during bird surveys and daily average noise levels)and vegetation cover with bird species richness.Methods:This study was conducted in the city of Xalapa(Mexico)through a 114 citywide point‑count survey.We recorded bird communities at each sampling site.We measured noise levels using a sound level meter while performing point‑counts.Then,we generated a map of average daily noise of the city using an array of 61 autonomous recording units distributed across the city of Xalapa and calculated daily noise levels for the 114 points.We ran a linear model(LM)to assess potential relationships between both point‑count and daily(24 h)noise values and vegetation cover with bird richness.Results:Results from the LM show:(1)a negative relationship between maximum point‑count noise and avian species richness,(2)no relationship between 24 h noise and bird species richness,and(3)a positive relationship between vegetation cover and bird species richness.Conclusions:Results provide evidence that decreases in urban bird species richness do not necessarily imply the permanent absence of species,suggesting that birds can temporarily fly away from or avoid sites when noisy,become cryptic while noisy events are occurring,or be undetected due to our inability to record them in the field during noisy events.

Prioritizing and Providing Sound Pollution Control Strategies at the CPF of North Azadegan Oilfield Project

Among the harmful occupational factors,noise is the most common exposure in the oil industrial workplaces.The present study aimed to prioritize sound pollution areas in central processing facilities(CPF)of an oil field in order to provide corrective action in the studied industry and similar industries.After reviewing the issued permit to work,job description and noise dosimetry test,the evaluated areas were selected then sound pressure levels in the referenced areas investigated according to ISO 9612–2009(E)next the noise map prepared for all selected areas.For identifying the prioritized areas to implement the control measures NCPI was used.After identifying the first priority area with sound pressure levels greater than 85 dB,the frequency analysis was performed and Isosonic map was prepared by Surfer v10 and AutoCAD 2014.In the last step,in order to provide appropriate corrective action plan,the compatibility of the determined control actions with the production process was examined.The findings of this study indicates that 74%of the aforesaid area has the first priority to perform control measures in the caution zone and the remaining 26%is in the danger zone.In this study it has been demonstrated that implementing control measures for Zone 2 have first priority.The main source of the noise in this zone is fluid(Gas)flow through the piping and HP Gas Compressors.The results of this study shows that using effective factors such as exposure time,sound pressure level and number of exposed persons,can be present suitable model to prioritize noise control.

Changes in call properties of Boana pulchella (Anura, Hylidae) in response to different noise conditions

The increasing expansion of urban areas leads to the emergence of new noisy environments that can affect animal communication.Calls play a crucial role in the mating displays of anurans,and the negative impact of anthropogenic noise-induced auditory masking has been reported in several species.We investigated the acoustic variation in 96 males(n=971 calls)of the treefrog Boana pulchella across acoustically undis-turbed sites and different noise conditions,associated with urban areas(URBAN)and roads(ROAD),in Central Argentina.We analyzed the effect of anthropogenic noise conditions on 6 temporal(call duration[CD],intercall interval,first and second note duration,internote interval,and call rate)and 3 spectral(dominant frequency of first and second note,frequency difference between them)call properties.The effects of temperature and size on acoustical variables were controlled.We observed differences in all call attributes among the noise conditions,except for intercall interval.Males exposed to URBAN and ROAD exhibited significant changes in CD,dominant frequency of the second note,and fre-quency difference between them.URBAN males had longest internote interval,while ROAD individuals displayed increased first and second note duration and call rates.Interestingly,ROAD males exhibited immediate changes in call rate in direct response to passing heavy vehicles.Our study emphasizes the impact of anthropogenic noise on the acoustic characteristics of B.pulchella calls.Understanding how animals adapt to noisy environments is crucial in mitigating the adverse effects of urbanization on their communication systems.Future investigations should explore whether the observed call adjustments are effective in avoiding or mitigating the negative consequences of anthropogenic noise on reproductive success.

Perception of the Residential Environmental Quality of Yenagoa Metropolis,Nigeria

Residential environmental quality(REQ)affects human health and quality of life(QoL).Therefore,this study as­sessed residents’perception of the REQ of the Yenagoa metropolis.Data for the study were sourced from the 400 ad­ministered questionnaires,which required respondents to rate their REQ based on seven selected indicators(air quality,drinking water quality,housing location,sanitation,waste management,housing accessibility and noise pollution).The respondents were sampled using the multistage sampling technique.The data were analyzed using frequency,percent­age,t-test,ANOVA and REQ model.The findings show that the overall calculated REQ of Yenagoa was classified as“good quality”.The best-rated indicator was drinking water quality,while the least-rated was noise pollution.Ratings based on respondents’sex,income and educational status recorded similar results.Also,the respondents’perception of the REQ across the four zones was similar as the calculated ratings of all the zones fell under the“good quality”classification.Furthermore,the hypotheses tested revealed that there were no significant differences in the perception of the REQ by sex and income status,while significant variation exists by education status.Despite the general“good quality”rating,there is still room for improvement,especially in the areas of noise pollution,sanitation and housing location,which received relatively low ratings.

GIS model for identifying urban areas vulnerable to noise pollution： case study

The unprecedented expansion of the national car ownership over the last few years has been determined by economic growth and the need for the population and economic agents to reduce travel time in progressively expanding large urban centres. This has led to an increase in the level of road noise and a stronger impact on the quality of the environment. Noise pollution generated by means of transport represents one of the most important types of pollution with negative effects on a population＇s health in large urban areas. As a consequence, tolerable limits of sound intensity for the comfort of inhabitants have been determined worldwide and the generation of sound maps has been made compulsory in order to identify the vulnerable zones and to make recommendations how to decrease the negative impact on humans. In this context, the present study aims at presenting a GIS spatial analysis model-based methodology for identifying and mapping zones vulnerable to noise pollution. The developed GIS model is based on the analysis of all the components influencing sound propagation, represented as vector databases （points of sound intensity measurements, buildings, lands use, transport infrastructure）, raster databases （DEM）, and numerical databases （wind direction and speed, sound intensity）. Secondly, the hourly changes （for representative hours） were analysed to identify the hotspots characterised by major traffic flows specific to rush hours. The validated results of the model are represented by GIS databases and useful maps for the local public administration to use as a source of information and in the process of making decisions.

Environmental health perspectives for low- and middle-income countries

In recent decades, the ecological environment has been increasingly challenged by the development of global industrialization and urbanization all over the world, even as global attention for health has raised dramatically. Common global environmental issues, such as air pollution and noise pollution, are associated with lasting impacts on health and contribute significantly to the overall burden of disease. Moreover, a global disparity exists between the burden of such environmental health issues and the global resources available to address this issue. To alleviate the environmental health impacts and ensure a sustainable future for human beings, China has made an important contribution to improving access to ecological protection, environmental governance, patriotic health campaigns, smart city construction, and so on. Experiences gained in China may be useful for some other countries, particularly the low- and middle-income countries with limited sources.

The effect of urbanization and exposure to multiple environmental factors on life-history traits and breeding success of Barn Swallows(Hirundo rustica)across China

In addition to landscape changes,urbanization also brings about changes in environmental factors that can affect wildlife.Despite the common referral in the published literature to multiple environmental factors such as light and noise pollution,there is a gap in knowledge about their combined impact.We developed a multidimensional environmental framework to assess the effect of urbanization and multiple environmental factors(light,noise,and temperature)on life-history traits and breeding success of Barn Swallows(Hirundo rustica)across rural to urban gradients in four locations spanning over 2500 km from North to South China.Over a single breeding season,we measured these environmental factors nearby nests and quantified landscape urbanization over a 1km~2radius.We then analysed the relationships between these multiple environmental factors through a principal component analysis and conducted spatially explicit linear-mixed effects models to assess their effect on lifehistory traits and breeding success.We were particularly interested in understanding whether and how Barn Swallows were able to adapt to such environmental conditions associated with urbanization.The results show that there is significant variation in the exposure to environmental conditions experienced by Barn Swallows breeding across urbanization gradients in China.These changes and their effects are complex due to the behavioural responses ameliorating potential negative effects by selecting nesting sites that minimize exposure to environmental factors.However,significant relationships between landscape urbanization,exposure to environmental factors,and life-history traits such as laying date and clutch size were pervasive.Still,the impact on breeding success was,at least in our sample,negligible,suggesting that Barn Swallows are extremely adaptable to a wide range of environmental features.

Effect of Plastocene Embedment in the Microperforated Plate on Its AcousticPerformance

Noise pollution is one of the contemporary environmental pollution, which seriously damages people’s green andhealthy life. In order to further improve the low frequency sound absorption performance of microperforatedpanel (MPP), a new plastocene coupled microperforated plate (PCMPP) is proposed. The acoustic propertiesof PCMPP with different apertures and perforation ratio were measured by transfer function method and compared with that of conventional MPPs. It is found that when the aperture was 0.8 mm, the peak value of soundabsorption coefficient of PCMPP decreased by 150 Hz compared with MPP. In a certain range, PCMPP with larger apertures showed a greater influence on sound absorption property in low frequency. In addition, higher perforation ratio led to a greater PCMPP bandwidth of sound absorption. On the other hand, the effect of PCMPPwith aperture of 0.2 mm on the performance of MPP was reduced, which could be compensated by increasing theperforation ratio. Furthermore, we found that the effect of aperture, perforation ratio and cavity on the soundabsorption performance of PCMPP was consistent with that of ideal rigid MPP. The step cooling curve showedthat the plastocene began to soften at about 50℃, representing a great potential for a non-high temperaturework environment.

Comparison of simultaneous signals obtained from a dual-field-of-view lidar and its application to noise reduction based on empirical mode decomposition

Although the empirical mode decomposition （EMD） method is an effective tool for noise reduction in lidar signals, evaluating the effectiveness of the denoising method is difficult. A dual-field-of-view lidar for observing atmospheric aerosols is described. The backscattering signals obtained from two channels have different signal-to-noise ratios （SNRs）. The performance of noise reduction can be investigated by comparing the high SNR signal and the denoised low SNR signal without a simulation experiment. With this approach, the signal and noise are extracted to one intrinsic mode function （IMF） by the EMD- based denoising; thus, the threshold method is applied to the IMFs. Experimental results show that the improved threshold method can effectively perform noise reduction while preserving useful sudden-change information.

Bats adjust temporal parameters of echolocation pulses but not those of communication calls in response to traffic noise

Many studies based on acute short-term noise exposure have demonstrated that animals can adjust their vocal­izations in response to ambient noise.However,the effects of chronic noise over a relatively long time scale of multiple days remain largely unclear.Bats rely mainly on acoustic signals for perception of environmental and social communication.Nearly all previous studies on noise-induced vocal adjustments have focused on echo­location pulse sounds.Relatively little is known regarding the effects of noise on social communication calls.Here,we examined the dynamic changes in the temporal parameters of echolocation and communication vocal­izations of Vespertilio sinensis when exposed to traffic noise over multiple days.We found that the bats start­ed to modify their echolocation vocalizations on the fourth day of noise exposure,with an increase of 42-91%in the total number of pulse sequences per day.Under noisy conditions,the number of pulses within a pulse se­quence decreased by an average of 17.2%,resulting in a significantly slower number of pulses/sequence(P<0.001).However,there was little change in the duration of a pulse sequence.These parameters were not signifi­cantly adjusted in most communication vocalizations under the noise condition(all P>0.05),except that the duration decreased and the number of syllables/sequences increased in 1 type of communicative vocalization(P<0.05).This study suggests that bats routinely adjust temporal parameters of echolocation but rarely of com­munication vocalizations in response to noise condition.