Equivalent Noise Level Research Articles

Comparing Traffic Noise Levels between Signalized Intersections and Roundabouts in an Urban Environment

This study aims to investigate and compare the traffic noise generated from signalized intersections and roundabouts. Hourly equivalent traffic noise level, traffic volume, and weather data were collected at four signalized intersections and four roundabouts of different sizes (two-lane and three-lane). Data were collected for a total period of 32 h during one weekday and one weekend at each intersection. A comparative traffic noise analysis that focused on peak hours was conducted between the different types of intersections. When comparing intersections of similar type and size, intersections with higher traffic volume produced higher traffic noise levels. However, when comparing intersections of different types and sizes, the two-lane roundabouts had lower traffic volume than the three-lane roundabouts but generated much higher traffic noise levels. When compared with two-lane signalized intersections, the two-lane roundabouts generated a much higher traffic noise with a slightly higher traffic volume. Similarly, the three-lane signalized intersections performed better than the three-lane roundabouts with marginally higher traffic noise levels and a much higher traffic volume. The results indicated that signalized intersections can be a better option than roundabouts from a traffic noise perspective when traffic volume is expected to be high.

Impact of topography on attenuation of noise from a cement plant in a hilly terrain

The influence of hill topography on noise from industrial plants is scantly documented, despite the fact that the noise profiles can vary in plains and in hilly terrain. Significant noise data from a cement plant flanked by hills were collected and analyzed for its attenuation over space in the direction of the valley and across the hills. It was observed that the noise attenuation is not similar to that experienced in plains owing to interactions with the mountains. The overall effect has been modelled over different distances between the four sources of the noise and several monitoring stations. The analyzed noise data showed that the influence of the major source of noise is obvious, yet difficult to differentiate. An iterated weighted distance from the noise sources, proved to be a better estimate for distance while modelling the attenuation of the noise. A relationship between the equivalent noise levels during the day and night could also be established. The effect of relative altitude and slope could be modelled using nonlinear multivariate analysis and the response surfaces were obtained for minimum, maximum and average values of the variables. Noise shadow zones could be identified with noise contouring which reflects reduction in the noise levels on hind side of the hills. The impact of topography and possible interference could thus be defined in such hilly terrain. The information can be used to define the noise mitigation strategies for adjacent habitats and mitigation of human response. The findings of the paper can also be used by prospective plants in hilly areas.

Equivalent noise characterization of human lightness constancy.

A goal of visual perception is to provide stable representations of task-relevant scene properties (e.g. object reflectance) despite variation in task-irrelevant scene properties (e.g. illumination and reflectance of other nearby objects). To study such stability in the context of the perceptual representation of lightness, we introduce a threshold-based psychophysical paradigm. We measure how thresholds for discriminating the achromatic reflectance of a target object (task-relevant property) in rendered naturalistic scenes are impacted by variation in the reflectance functions of background objects (task-irrelevant property), using a two-alternative forced-choice paradigm in which the reflectance of the background objects is randomized across the two intervals of each trial. We control the amount of background reflectance variation by manipulating a statistical model of naturally occurring surface reflectances. For low background object reflectance variation, discrimination thresholds were nearly constant, indicating that observers’ internal noise determines threshold in this regime. As background object reflectance variation increases, its effects start to dominate performance. A model based on signal detection theory allows us to express the effects of task-irrelevant variation in terms of the equivalent noise, that is relative to the intrinsic precision of the task-relevant perceptual representation. The results indicate that although naturally occurring background object reflectance variation does intrude on the perceptual representation of target object lightness, the effect is modest – within a factor of two of the equivalent noise level set by internal noise.

Noise Pollution Assessment in Sylhet City Corporation Using Geographic Information System (GIS)

Background: Noise pollution is a risk factor for human health which is continuously increasing in Sylhet City corporation, located in the Sylhet division in Bangladesh. Methods: In this study, we assessed the noise pollution level in Sylhet City by comparing it with the standard noise level. Also, the outcomes of this study were compared to other studies from different countries. In order to measure the noise level in decibel, BSWA 308 device was used in this study. A total of 38 samples were taken from different geographical locations in Sylhet City Corporation. The 38 samples provided 96 to 99% accuracy with a 95% confidence level of >36. Results: The decibel values ranged from 72 to 86 dB. From the observed data we calculated the values as follows: L10, L50 and L90 and Noise Climate (NC)=12.7 dB, equivalent continuous noise level Leq=77.18 dB and noise pollution level Lnp=89.88 dB. A contour map of the area was made using Arc GIS software version 10.5. Every line in the contour map defined a specific decibel value. The map was made by 2 dB intervals between the corresponding contour lines. More than 30% of the study area was vulnerable to a high level of noise (>82 dBA), and about 30% had the lower level of noise (<77 dBA). Only 40% of the area had moderate noise levels (i.e., between 77 to 82 dBA). Conclusion: After comparing the outcomes of noise level in this study with previous studies, we observed that the noise level of this area was more than acceptable limit for all parameters.

Bottom-Up and Top-Down Attention Impairment Induced by Long-Term Exposure to Noise in the Absence of Threshold Shifts.

ObjectiveWe aimed to assess the effect of noise exposure on bottom-up and top-down attention functions in industrial workers based on behavioral and brain responses recorded by the multichannel electroencephalogram (EEG).MethodIn this cross-sectional study, 563 shipyard noise-exposed workers with clinical normal hearing were recruited for cognitive testing. Personal cumulative noise exposure (CNE) was calculated with the long-term equivalent noise level and employment duration. The performance of cognitive tests was compared between the high CNE group (H-CNE, >92.2) and the low CNE group; additionally, brain responses were recorded with a 256-channel EEG from a subgroup of 20 noise-exposed (NG) workers, who were selected from the cohort with a pure tone threshold <25 dB HL from 0.25 to 16 kHz and 20 healthy controls matched for age, sex, and education. P300 and mismatch negativity (MMN) evoked by auditory stimuli were obtained to evaluate the top-down and bottom-up attention functions. The sources of P300 and MMN were investigated using GeoSource.ResultsThe total score of the cognitive test (24.55 ± 3.71 vs. 25.32 ± 2.62, p < 0.01) and the subscale of attention score (5.43 ± 1.02 vs. 5.62 ± 0.67, p < 0.001) were significantly lower in the H-CNE group than in the L-CNE group. The attention score has the fastest decline of all the cognitive domain dimensions (slope = −0.03 in individuals under 40 years old, p < 0.001; slope = −0.06 in individuals older than 40 years old, p < 0.001). When NG was compared with controls, the P300 amplitude was significantly decreased in NG at Cz (3.9 ± 2.1 vs. 6.7 ± 2.3 μV, p < 0.001). In addition, the latency of P300 (390.7 ± 12.1 vs. 369.4 ± 7.5 ms, p < 0.001) and MMN (172.8 ± 15.5 vs. 157.8 ± 10.5 ms, p < 0.01) was significantly prolonged in NG compared with controls. The source for MMN for controls was in the left BA11, whereas the noise exposure group's source was lateralized to the BA20.ConclusionLong-term exposure to noise deteriorated the bottom-up and top-down attention functions even in the absence of threshold shifts, as evidenced by behavioral and brain responses.

Effects of COVID-19 lockdown in Milan urban and Rome suburban acoustic environments: Anomalous noise events and intermittency ratio.

The COVID-19 pandemic affected the acoustic environment worldwide, entailing relevant reductions of equivalent noise levels (LAeq) during this exceptional period. In the context of the LIFE+ DYNAMAP project, two wireless acoustic sensor networks were deployed in Milan and Rome. Taking advantage of the built-in identification of anomalous noise events (ANE) in the sensors, this work analyses the effects of the COVID-19 lockdown in both urban and suburban acoustic environments from January to June 2020, considering the distribution of ANEs and the intermittency ratio (IR) as an indicator of the impact of noise on population. The results show statistically significant increments of ANEs in Rome during the lockdown, mainly on weekends, and especially at night, despite the significant decrease in salient events. Differently, ANEs decrease during the lockdown in Milan, mostly at daytime, as a result of population confinement. Although the IR increases in several urban locations, most sensed locations show a relevant decrease in IR during the confinement, which represents a noteworthy reduction of the negative impact of noise in the population of both cities. During the post-lockdown period, all the scores start to return to those observed in the pre-lockdown, but still remaining higher than in 2019.

Statistical modelling for urban roads traffic noise levels

Traffic noise is one of the most significant types of vehicular emissions that result in physical and psychological health effects on humans and is caused by an increase in vehicular ownership and urbanisation. The central business district (CBD) of Ondo has been exposed to persistent road traffic and commercial activities due to development and expansion of the economy, and this has led to an increase in traffic noise levels. Due to the increase in traffic volume, urbanisation, and population deterioration of road pavements in the CBD, it was hypothesised that noise related to traffic has increased and is above the permissible limit of the World Health Organisation in the study area. Monitoring noise levels by administrative agencies will help mitigate traffic noise intensity and aid in urban planning. This study examined the traffic noise levels and developed models for the CBD of Ondo, Nigeria. Adopting the empirical methods of the Calculation of Road Traffic noise (CoRTN) model and statistical Multiple Linear Regression (MLR) modelling approach, traffic noise models for the assessment of equivalent noise levels (Leq) at the CBD of Ondo were developed. Over 90% of the roadsides surveyed were above the world health organization's 70 dB(A) threshold. Correlation between CoRTN and MLR models demonstrated reliable efficiency relative to observed noise levels with an acceptable coefficient of determination (R2) values of 0.943 and 0.963, respectively. The deviation between the noise levels measured with the expected noise levels (MLR and CoRTN) varied, between 0.44 dB(A) and 2.09 dB(A) with an average mean difference of 0.37 dB(A) to 1.9 dB(A). These values are adjudged satisfactory since it is within the +/- 3.0 (dB)A allowed by the Federal Highway Administration (FHWA). The models are therefore robust and accurate in estimating the level of noise from road traffic for the study area.

Low-Overhead Fault-Tolerant Quantum Error Correction with the Surface-GKP Code

Fault-tolerant quantum error correction is essential for implementing quantum algorithms of significant practical importance. In this work, we propose a highly effective use of the surface-GKP code, i.e., the surface code consisting of bosonic GKP qubits instead of bare two-dimensional qubits. In our proposal, we use error-corrected two-qubit gates between GKP qubits and introduce a maximum likelihood decoding strategy for correcting shift errors in the two-GKP-qubit gates. Our proposed decoding reduces the total CNOT failure rate of the GKP qubits, e.g., from $0.87\%$ to $0.36\%$ at a GKP squeezing of $12$dB, compared to the case where the simple closest-integer decoding is used. Then, by concatenating the GKP code with the surface code, we find that the threshold GKP squeezing is given by $9.9$dB under the the assumption that finite-squeezing of the GKP states is the dominant noise source. More importantly, we show that a low logical failure rate $p_{L} < 10^{-7}$ can be achieved with moderate hardware requirements, e.g., $291$ modes and $97$ qubits at a GKP squeezing of $12$dB as opposed to $1457$ bare qubits for the standard rotated surface code at an equivalent noise level (i.e., $p=0.36\%$). Such a low failure rate of our surface-GKP code is possible through the use of space-time correlated edges in the matching graphs of the surface code decoder. Further, all edge weights in the matching graphs are computed dynamically based on analog information from the GKP error correction using the full history of all syndrome measurement rounds. We also show that a highly-squeezed GKP state of GKP squeezing $\gtrsim 12$dB can be experimentally realized by using a dissipative stabilization method, namely, the Big-small-Big method, with fairly conservative experimental parameters. Lastly, we introduce a three-level ancilla scheme to mitigate ancilla decay errors during a GKP state preparation.

Assessment and Appraisal of Morning Peak Time Urban Road Traffic Noise at Selected Locations of Major Arterial Roads of Surat City, India

Urban traffic noise is emerging as a crucial problem in the 21st century. Variation in the level of noise from urban traffic causes several health-related issues. This study demonstrates the noise assessment and appraisal of morning peak time urban road traffic noise at selected locations of major arterial roads of Surat city. The noise is compared against the norms and standards given by the noise pollution (Regulation and Control) Rules, 2000. MoEF&amp;CC has published the Ambient Air Quality Standards in respect of noise under Rule 3(1) and Rule 4(1) as per Schedule in the annexe. In this research work, noise levels were measured at four different locations from Athwa line chowk to Dumas Road of Surat city. Traffic count has been done by calculating the numbers of two wheelers, three-wheelers, four-wheelers, and heavy vehicles (bus &amp; truck). The A-weighted sound level was 78.9 dB(A) near the urban road, which exceeds the standard value recommended by CPCB. The maximum equivalent noise level was 114.9dB at Sushrut hospital, while the minimum was 46.1 dB at Keval chowk. Finally, the study indicates an increment in noise levels with an increment in the count of vehicles. The factors causing the increased noise levels are traffic flow, horn honking, lane indiscipline, heterogeneous traffic condition, morning rush, etc.

WASN-Based Spectro-Temporal Analysis and Clustering of Road Traffic Noise in Urban and Suburban Areas

Environmental noise has become one of the principal health risks for urban dwellers and road traffic noise (RTN) is considered to be the main source of these adverse effects. To address this problem, strategic noise maps and corresponding action plans have been developed throughout Europe in recent years in response to the European Noise Directive 2002/49/EC (END), especially in populated cities. Recently, wireless acoustic sensor networks (WASNs) have started to serve as an alternative to static noise maps to monitor urban areas by gathering environmental noise data in real time. Several studies have analysed and categorized the different acoustic environments described in the END (e.g., traffic, industrial, leisure, etc.). However, most of them have only considered the dynamic evolution of the A-weighted equivalent noise levels LAeq over different periods of time. In order to focus on the analysis of RTN solely, this paper introduces a clustering methodology to analyse and group spectro-temporal profiles of RTN collected simultaneously across an area of interest. The experiments were conducted on two acoustic databases collected during a weekday and a weekend day through WASNs deployed in the pilot areas of the LIFE+ DYNAMAP project. The results obtained show that the clustering of RTN, based on its spectro-temporal patterns, yields different solutions on weekdays and at weekends in both environments, being larger than those found in the suburban environment and lower than the number of clusters in the urban scenario.

Hearing loss symptoms and leisure noise exposure in university students in Barranquilla, Colombia.

The aim of this study was to investigate the total weekly exposure to leisure noise among university students and to assess its association with self-reported symptoms of hypoacusis. This is a cross-sectional survey. An online questionnaire based on the "Noise Exposure Questionnaire", plus 11 questions regarding hearing loss were sent to 730 randomly selected students. Participants self-reported time spent on different leisure noise activities and their subjective evaluation of the loudness of these activities, converted into equivalent noise levels, were used to estimate weekly noise exposure levels that were compared to occupational noise limits (> 85 dBA = hazardous). Inference statistics was applied to relate hearing symptoms and "likely or having some degree of hearing loss" with hazardous weekly leisure noise exposure levels. Ninety-three percent of the participants reported at least one hypoacusis symptom. The most frequent sound-related ear symptom was tinnitus (72%). Fifty-five percent of the individuals presented weekly exposure to noise >85 dBA. Symptoms of hearing loss were more prevalent in those exposed to weekly noise levels >85 dBA. This study suggests that there may be hearing loss caused by exposure to high levels of leisure noise in a large part of the study population. Health promotion of hearing conservation should be emphasized at university level. Objective repeated measurement of hearing acuity should be part of integral health services for the youth population.

Noise pollution in rail transport. Case study: Baghdad subway

Abstract Noise pollution is one of the environmental factors that severely threaten humans’ mental, emotional, and physical health. One of the most significant sources of this pollution is the noise generated by traffic and urban transportation, mainly the urban railway. This paper assessed noise pollution at stations, passenger cars, and the train operator’s cabin. Four consecutive Baghdad subway stations were used to collect information. There were three modes of measurement: entering the station, stopping at the station, and leaving the station. L eq (equivalent continuous noise level) at station 3 is more significant than at three other stations, confirming that the initial hypothesis regarding the noise pollution rate was correct. Among the studied stations, Station 1 was the quietest. The stations with the highest and lowest L eq values are 3 and 2, respectively. The L eq values recorded in the cabin are within the permissible range. The highest L eq value measured at station 3 is 81.87 dB(A), and the lowest L eq value measured at station 2 is 61.24 dB(A). The operator’s cabin at station 3 has the highest measured L eq of 70.26 dB(A), and station 1 has the lowest measured L eq of 61.5 dB(A). While the measured value in the operator’s cabin was within the acceptable range, the noise levels in the wagons were above standard.

Povezanost između komunalne buke i arterijske hipertenzije kod stanovnika grada Niša

Aim: The aim of the study was to examine the relationship between noise exposure and the incidence of arterial hypertension as well as the relationship of noise annoyance and noise sensitivity with hypertension. Methods: A cross-sectional questionnaire survey was performed on 911 adult residents of Niš, Serbia, of whom 388 were men (42.6%) and 523 women (57.4%). The criterium for the diagnosis of arterial hypertension was that it was diagnosed by a physician. Based on measurement results of noise, residents, streets were marked as noisy [daily equivalent noise level (Leq) ≥ 55 dB (A) and night Leq ≥ 45 dB (A)] and as quiet [daily equivalent noise level (Leq) ≤ 55 dB (A) and night Leq ≤ 45 dB (A)]. The numerical and verbal noise annoyance scales were used to assess the degree of noise annoyance, while noise sensitivity was measured with the Weinstein's Noise Sensitivity Scale. Results: Arterial hypertension was statistically significantly more frequent in residents in the noisy area compared to residents in the quiet area. After the inclusion of independent variable factors in the logistic regression models, no significant diference was found (p = 0.66, OR = 1.11; 95% CI: 0.69-1.78). A correlation analysis between noise annoyance wich was measured by verbal and numeric scales and arterial hypertension showed a highly significant positive relation. The same case was between the relationship between subjective sensitivity and arterial hipertension. Conclusion: The introduction of the limit for the community noise level that corresponds to the requirements of highly sensitive persons is a significant measure in preventing the harmful effects of noise on the exposed population.

Noise Level inside Sri Lanka Transport Board Buses and Hearing Impairment of Long- and Short-Distance Bus Drivers of Ampara and Batticaloa Districts, Sri Lanka.

Background:Transport drivers are more vulnerable to hearing impairment due to the traffic environment and fast-growing urbanization.Objective:The study aims to determine the noise level inside the Sri Lanka Transport Board (SLTB) buses, hearing impairment of state transport bus drivers, and its associated factors in the selected districts of Eastern Province, Sri Lanka.Materials and Methods:A cross-sectional descriptive study was carried out among 256 state bus drivers using a systematic sampling technique. A screening tool to assess the level of hearing impairment of drivers and a format to measure equivalent noise level inside the SLTB buses were used to collect data. Noise measurement was done using Benetech Sound Level Meter (Model DB 130).Results:With reference to the noise level inside buses, 88.4% (n = 53) exceeded 85 dB (A), and 21.7% of buses (n = 13) were above 90 dB (A). According to the hearing tool's hearing impairment assessment, the hearing of the majority of the study participants (84.4%, n = 216) was not affected. The association between hearing impairment and past history of ear diseases, surgeries, or head trauma was statistically significant (P = 0.017).Conclusions:Noise level inside the SLTB buses in Ampara and Batticaloa districts exceeded the 85 dB limit prescribed under the WHO standards of occupational noise exposure. The years of service of a bus was the only factor shown a statistically significant association with the level of noise inside the bus.

The acoustic climate of spaces located under overpasses in the context of adapting them for outdoor public events – a pilot case study

Due to the current shortage of traditional public space because of its privatization, commercialization, and securitization, there is an urgent need to reclaim areas affected by motorized traffic in the urbanized areas. On the other hand, the process of adapting them for new purposes should be carefully carried out, addressing several issues, among them environmental acoustics. This study is meant to contribute to our understanding of acoustic conditions of a general model of the bridge underspace. Therefore, the aim of the research was to examine the existing acoustic climate by measuring noise levels and comparing them with equivalent acceptable noise levels for the expected type of space development and Noise Rating curves. In this research, a pilot case study approach was used, as measurements were taken for a chosen space located under an elevated road that represents certain criteria set by the researchers. The results allowed us to: (1) verify the relationship between the geometry of the bridge underspace and the noise levels, (2) assess the initial acoustic conditions in terms of possibilities of acoustic adaptation of the examined space for outdoor public events, and (3) formulate hypotheses and preliminary assumptions for the planned further and broader studies of the issues raised in this article. The presented results and their analysis show that it is possible to bring the acoustic conditions in the studied space to the state required for public or cultural meeting spaces. In comparison with earlier findings, the research undertaken appears to be pioneering and the results can be used as valuable input for further research on this topic.

Impact of COVID-19 lockdown on ambient noise levels in seven metropolitan cities of India

The paper analyzed the impact of lockdown on the ambient noise levels in the seventy sites in the seven major cities of India and ascertained the noise scenario in lockdown period, and on the Janta Curfew day in comparison to the pre-lock down period and year 2019 annual average values. It was observed that the majority of the noise monitoring sites exhibited a decrement in ambient day and night equivalent noise levels on the national Janta Curfew day and Lockdown period as compared with the normal working days attributed to the restricted social, economical, industrial, urbanization activity and reduced human mobility. A mixed pattern was observed at a few sites, wherein the ambient day and night equivalent noise levels during Janta curfew day and Lockdown period had been reported to be higher than that on the normal working days. The study depicts the noise scenario during the lockdown and pre-lockdown period for seventy sites in India and shall be instrumental in analyzing the consequences and implications of imposing lockdowns in future on the environmental noise pollution in Indian cities.

Prediction of occupational exposure limits for noise-induced non-auditory effects

There is a recent trend to place more emphasis on noise non-auditory effects. Despite its implications on health, there is a lack of recommendations for noise in occupational settings. This study aimed to present occupational exposure limits for noise-induced non-auditory effects in healthy males using empirical exposure-response regression models based on the data of laboratory and field considering the effective variables. To this end, the equivalent noise level was measured and recorded in four working settings including closed offices, open-plan offices, control rooms, and industrial workplaces during a normal working day. They were 65, 68, 73, and 80dB(A), respectively. In the laboratory, 31 healthy males were exposed to five noise conditions (four noisy conditions and one quiet) during 8 h and they were asked to perform the cognitive tests. In the field phase, 124 healthy males were also examined from four working settings in their workstations for 8 h. The psychophysiological parameters of the participants were recorded in both lab and field. The results indicated variations in mental responses at levels above 55dBA, and psychophysiological variations at levels above 70dB(A) in both phases. The findings also showed that the developed regression models could plausibly predict the noise-induced psychophysiological responses during exposure to noise levels; thus, they can be presented the likely exposure limits. Based on the results of the models, the levels <55dB(A) are likelihood of the acoustic comfort limit, and the levels ranged from 55 to 65dB(A) are the acoustic safe limits. The acoustic caution limit is the likelihood of the levels ranged from 65 to 75dB(A). The levels ranged from 75 to 80dB(A) are likely the action levels or control limits, and the occupational exposure limit are the probability of levels> 80dB(A).

Sanitary and hygienic assessment of working conditions of civil aviation pilots

Introduction. The analysis of working conditions of pilots of civil aviation aircraft has been carried out according to the data of sanitary and hygienic characteristics (SHC). The non-compliances with hygiene standards for several factors have been established at the same time in all SHC. Materials and methods. The 220 SHC of pilots, who had been examined in the clinic of FSBSI RIOH due to suspicion of occupation disease from 2015 to 2019, conducting flights by plane (49%) and helicopter (51%) were analyzed. The methods of account of acoustic load, hygiene assessment and classification of working conditions, peer review methods, and statistical treatment methods have been used. Results. The working conditions, according to the criteria of the Guide R 2.2.2006-05, are assigned to the following classes: 3.2 - in 26%; 3.3 - in 41%; 3.4 - in 33%. Exceeding the permissible equivalent noise levels was recorded at 92% of workplaces. According to SHC, the exceedances were from 1.2 dB to 34.5 dB (class 3.1-3.4). In assessing the work intensity in 83% of cases from 5 to 11 indicators of class 3.2 were recorded. It has determined class 3.3 of work intensity. The levels of general vibration exceeded hygiene standards in 48% of cases (class 3.1- 3.2), local vibration - in 8% (class 3.1-3.2), microclimate parameters - in 67% (class 3.1-3.2), labour severity - in 22% (class 3.1-3.3), less often there were discrepancies in light (6%) and chemical factor (2%). Conclusion. According to a combination of factors, the overall assessment of working conditions of the pilots of civil aviation aircraft in 74% of cases is assigned to classes 3.3-3.4. However, the disadvantages and errors in filling out the SHC can underestimate the degree of harmfulness of the work. To improve the procedure of establishing the connection between the disease, and the profession it is necessary to amend the legislative framework to obtain objective information about the levels of factors affecting pilots, develop a separate form of SHC of working conditions of pilots, detailed instructions about the rules of filling out SHC.

Prediction of Road Traffic Noise by CRTN Model in a Sub-Urban Town of India

Present study was undertaken for assessment of spatial characteristics of road traffic noise at varying intervals viz early morning (8-9 am), late morning (11-12 pm), afternoon (2-3 pm) and evening (6-7 pm) time at ten important locations (near school building) of G. T. Road which is passing through the Burdwan town. Digital noise meter was used for recording the traffic noise and noise contour map was constructed by using Geographical Information System (GIS). The recorded data revealed that the highest and lowest average noise 67.1 dB (A) and 86.9 dB (A), respectively. The results revealed that the performance of the CRTN model in both afternoon and evening time for predicting noise level near school building with a coefficient of determination (R2) are 0.536 and 0.544 and a mean difference of - 1.19 dB (A) and - 0.48 dB (A) between the measured and predicted values respectively. Similarly, Pearson statistics also revealed the strong correlation between measured and predicted noise level at afternoon (r = 0.732, p &lt; 0.016) and evening time (r = 0.744, p &lt; 0.014). However, the predicted traffic noise during early morning and late morning hour are less than 0.5. These low values are due to irregular traffic speed, traffic density and irregular building height are the appropriate reasons for low accuracy in predicting model. Finally, it may be suggested that CRTN model can be a decision tool for predicting equivalent noise level in the city like Burdwan.

An Evaluation of Urban Environmental Noise Pollution in Durres Municipality

Durres is the second most populous place on the Republic of Albania. This paper was focused in the evaluation of noise level at different areas of Durres Municipality which were categorized based on their activities like industrial, commercial and residential. The main purpose of environmental noise monitoring was to assess the situation in Durres Municipality, to value the degree of impact on citizens and to create a database to better address the problems, in order to build an effective action plan to improve the situation in problem areas. Monitoring has two basic objectives, such as: to protect us from noise that hinders and disrupts our daily activity and to protect us in the future from increasing noise levels that would bring concerns to people and quality of the environment. To realize this study was used TESTO 816-1 supply that measures noise intensity level of a certain area. Measurements were carried out in different conditions of humidity and wind velocity, during morning and night time, from February 2019 to December 2020. Duration of each measurement was 15 min. The results of this study revealed that the average equivalent noise level was: i) in the commercial area (during morning time 51.92 dB, during night time 46.8 dB), in the industrial area (during morning time 57.69 dB, during night time 45.31 dB) and in the residential area (during morning time 53.59 dB, during night time 44.46 dB). As a conclusion it was evidenced that the noise levels for all the areas were over the permissible levels of 50 dB (during morning) and for commercial and industrial area were over 45 dB (during night). Also it was concluded that the consequences of these high levels cause moderate and serious annoyance for residents during the day and sleep disturbances (if windows are open) during the night. This paper suggests some improvements to decrease side effects of noise pollution.