Monitoring and Assessing the Environmental Noise along a Busy Traffic Corridor of Ahmedabad City, India

Noise pollution is a growing problem across the world and one which many people may not be aware of the impacts on their health. The environmental noise, and in particular the road traffic noise, remains a major environmental problem affecting the health and well-being of millions of people. With this background, a comprehensive ‘noise pollution assessment study’ was undertaken for a busy traffic corridor of Ahmedabad city of India. The traffic corridor which spans around 22.25 km passes through a mix of different areas like educational, commercials and residential. A two week long field survey was carried out on this corridor during 10-23 May, 2018 at 24 locations spread over the entire corridor. The assessment reveals that the average noise level always exceeded the prescribed guidelines of World Health Organization (WHO) for the daytime noise (75 dB (A) for Industrial area, 65 dB (A) for Commercial area, 55 dB (A) for Residential area and 50 dB (A) for Silence zones), which is quite alarming. For a major portion of the traffic corridor (79.6%), even the minimum noise level was above the permissible average noise level which is a matter of great concern. The highest noise level observed was 86.0 dB (A). Clubbing the ranks of the traffic corridor segments for the noise indicators like LAeq, Lmin, Lmax, L90, L50, L10 and LNP revealed that locations like Akhbarnagar followed by Naranpura were in the nosiest. Looking to implications of the high noise levels on the human health and productivity, it is important to initiate suitable mitigation measures. The present comprehensive study brings forth the spatial and quantitative aspects of noise pollution across the busy corridor of the city which would be of great help to the civic administration in understanding the magnitude of the problem and subsequently initiate suitable mitigative measures.

Underwater Ambient Noise in Kongsfjorden, Spitsbergen, during the Summers of 2015 and 2016

Underwater ambient noise was measured in Kongsfjorden, Svalbard, during the summers of 2015 and 2016 to understand the contribution of iceberg bubbling, iceberg calving, and shipping noise to the acoustic environment of the fjord. Comparison of the ambient noise data for the months of August, September, and October showed that average noise levels were similar, although the average noise level for 2015 was ~9 dB higher than in 2016 because of higher shipping noise. Maximum ambient noise was produced at frequencies less than 10 kHz during both summers. Spectrograms of iceberg calving noise showed that it occurred in the frequency below 500 Hz. Shipping noise was seen in the band below 600 Hz, and iceberg bubbling noise was detected in the band above 400 Hz. Instrument noise was observed in the frequency 400 Hz. It is clear that ice breaking and shipping contribute substantially to ambient noise in Kongsfjorden.

Analysis of frequency spectrum of outboard motor Hangkai 4.0 noise when nosing

The article deals with the results of experiments on measuring the Hangkai 4.0 outboard motor when using various types of noise-insulating hoods. The tests were carried out in accordance with GOST ISO 14509-1-2015 “Small Vessels. Noise measurement of small motor pleasure craft. Part 1. Noise of a passing ship” at full speed with the engine speed 4500 rev/min and motor power 4 HP. Measurements were carried out when the vessel was at a distance of 25 metres both sides with different options covering outboard motor. The average noise level and its frequency spectrum were measured, and the effectiveness of various types of hoods was evaluated. In the course of the experiment there was used a standard plastic hood of the Hangkai 4.0 engine, a noise-insulating hood (plastic hood, glued inside with automotive foil noise insulation) and an author's combined noise-insulating hood Kaponistr. Description and structural elements of Kaponistr are presented; it has been stated that the hood design was patented as a useful model in 2019. In the result of conducted experiments it has been inferred that the external noise level of the Hangkai 4.0 outboard motor (without hood) does not exceed 74.3 dBA, but is at the level of the permissible value of 75 dBA, so, when operating, the motor needs a standard hood. The prevailing frequency range of an outboard boat motor is within 300 - 2500 Hz. It has been inferred that each type of nosing (standard, sound-proof, combined, without hood) reduces the noise level of the outboard motor. The greatest effect of reducing external noise is observed when using a combined hood Kaponistr at a frequency of 800 Hz by 19.4 dBA or by 27%. In the research there were used the control and measuring devices (sound level meter, vibrometer, spectrum analyzer Ekofizika-110 (white); acoustic calibrator AK-1000) and software (Signal+3G Light manufactured by PKF Digital Instruments, LLC).

Noise metrics analysis in schools near airports: A Brazilian case study

This study compares metrics for environmental noise diagnosis in schools at airport vicinity. The goal is to analyze and identify the most suitable criteria for scaling aircraft noise impact over schools, during landing and take-off operations. A Brazilian case study is conducted, based on the noise mapping and sound level verification. The day-night average noise level (DNL) and the time above limit (TA) are investigated using acoustic simulation and noise mapping and in order to identify the critical receivers. Results of DNL and TA for two schools at airport surroundings show that the criteria adopted by the municipal and airport authorities to describe the airport noise are unsatisfactory and do not reflect the intermittent behavior of this type of noise. It was verified that individual receiver analysis, based on noise interruptions thought TA parameter is more suitable for evaluation of noise impact over schools at airport vicinity.

Vowels and Prosody Contribution in Neural Network Based Voice Conversion Algorithm with Noisy Training Data

This research presents a neural network based voice conversion model. While it is a known fact that voiced sounds and prosody are the most important component of the voice conversion framework, what is not known is their objective contributions particularly in a noisy and uncontrolled environment. This model uses a 3 layer feedforward neural network to map the Linear prediction analysis coefficients of a source speaker to the acoustic vector space of the target speaker with a view to objectively determine the contributions of the voiced, unvoiced and supra-segmental components of sounds to the voice conversion model. Results showed that vowels “a”, “i”, “o” have the most significant contribution in the conversion success. The voiceless sounds were also found to be most affected by the noisy training data. An average noise level of 40 dB above the noise floor were found to degrade the voice conversion success by 55.14 percent relative to the voiced sounds. The result also show that for cross-gender voice conversion, prosody conversion is more significant in scenarios where a female is the target speaker.

Prevalence of Noise-Induced Hearing Loss Among Tanzanian Iron and Steel Workers: A Cross-Sectional Study

Iron and steel factory workers in Tanzania are likely to develop noise-induced hearing loss (NIHL) due to exposure to high sound levels. Studies on hearing status in this population are lacking. The aims of this study were to determine prevalence of NIHL among iron and steel workers and compare hearing thresholds at different frequencies with a control group. We conducted a cross-sectional study among 221 iron and steel workers exposed to average noise level of 92 dB(A), compared with 107 primary school teachers recruited as controls and exposed to average noise level of 79.7 dB(A). We used a questionnaire-based interview to collect information on socio demographic characteristics and other confounding variables. Hearing loss was defined as hearing threshold levels ≥25 dB hearing loss in either ear at 3000, 4000 or 6000 Hz. The prevalence of hearing loss was significantly higher among the exposed group than among the controls, i.e. 48% and 31%, respectively. There were significant differences in hearing thresholds between the exposed and control groups at 3000, 4000, 6000, and 8000 Hz. Hearing loss was more frequent among workers exposed to higher noise levels than among the controls suggesting that iron and steel workers run a higher risk of developing hearing loss.

Effects of Occupational Noise on Blood Pressure

BACKGROUND: Noise has been found to have non auditory effects. One of the possible non auditory effects of noise is its effect on blood pressure. Available data on the effect of noise on blood pressure has been found to vary. Hence, the aim of this study was to find if there is a predictive effect of noise on blood pressure. METHOD: Study was done among sawmill workers in Ile-Ife. The noise in each sawmill was measured with a sound meter and blood pressure of each participants were recorded. A regression analysis was done using systolic and diastolic blood pressures as dependent variables and noise as the predictor. RESULTS: A total of 420 sawmill workers were recruited into the study with an average age of 33.53±8.59 years. The average noise level in the sawmill was 88±1.87 dB and the average systolic and diastolic blood pressures were 132 ± 21mmHg and 85 ± 13mmHg respectively. There was no significant effect of noise on systolic blood pressure {F (1, 419) = 0.958, P>0.05} but there was a significant effect of noise on diastolic pressure {F (1, 419) = 7.543, P<0.05}. CONCLUSION: This study found that exposure to noise is a predisposing factor to increase in blood pressure.

Application of the Bionic Concept in Reducing the Complexity Noise and Drag of the Mega High-Speed Train Based on Computer Simulation Technologies

Regarding the continuous development of high-speed trains and the increase of running speeds, the aerodynamic design of high-speed trains has become significantly important, while reduction of drag and noise comprises a significant challenge in order to optimize aerodynamic design of high-speed trains. The design form factor of a high-speed train is highly influenced by aerodynamic aspects including aerodynamic drag, lift force, and noise. With the high-speed train as the object, the paper aims to take bionic concept as the entry point, selecting the hummingbird as the bionic prototype and extracting bionic elements to establish a bionic train model. Then, the finite volume method was used for numerical simulation and analysis of the aerodynamic performance and aerodynamic noise of the bionic high-speed train. Computational results prove that drag and noise of the bionic head type were lower than those of the original train; drag of the head train of the bionic model was reduced by 2.21% in comparison with the original model, while the whole-train drag was reduced by 3.53%, indicating that drag reduction effects are available and implying that the bionic head type could reduce drag and noise. Noise sources of the bionic train are mainly located at positions with easy airflow separation and violent turbulence motion. Large turbulence energy is in bogie areas and mainly exists at the leeward side of the bogie area. Obviously, the bogie area is the major noise source of the train. Aerodynamic noise of the bionic train in far-field comprises a wide-frequency range. Noises were concentrated within 613 Hz~3150 Hz. When the bionic high-speed train ran at 350 km/h, through comparative analysis of total noise levels at observed points of the high-speed train, it is found that this position with the maximum noise level was 25 m away from the head train nose tip, with the maximum value of 88.4 dB (A). When the bionic train ran at 600 km/h, the maximum sound pressure level at the longitudinal point was 99.7 dB (A) and the average noise level was 96.6 dB (A). When the running speed increased from 350 km/h to 600 km/h, the maximum noise level increased by 11.3 dB (A) and the average noise level increased by 11.6 dB (A). Computation results of aerodynamic noise at the point which is 7.5 m away from the rail center show that the maximum aerodynamic noise level existed at the first-end bogie of the head train, while the noise level was larger at the position closer to the ground.

A comprehensive evaluation of the level of noise pollution in hospitals of Kermanshah University of Medical Sciences

Noise pollution higher than the standard values intensifies the patients' disease and also has negative effects on hospital staff. This study aimed to determine the level of noise pollution in the Kermanshah hospitals and also to compare obtained data with national and international standards. Multifunctional sound level meter (Model CEL – 450), has been applied for determining the sound level in different parts of a hospital in 3 different time of day (morning, visiting hours (evening), and night) for working day and holiday. The highest level was on working days and it was 60.24±5.76 dB. The average noise level on holiday was 58.15±5.44 dB. Generally, the average noise level in all studied hospitals was higher than the standard levels. The results of the analyses showed that when the P=0.003, there’s a significant difference between the average noise levels on different days. According to the results of the studies, it is necessary to plan and take managerial and technical – engineering measures to reduce the noise levels to standard levels.

TINGKAT KEBISINGAN LALU LINTAS DI LINGKUNGAN PERUMAHAN DALUNG PERMAI KABUPATEN BADUNG

Dalung Permai housing is that has a fairly high trip generation, many had access road leading to the workplace, both working in government, private as well as to schools and shopping centers and entertainment. Ahousingshouldprovideatranquility awayfrom the noisein accordancewith the Decree of the Governor of Bali No.8 Year 2007 on Environmental Quality Standards and Criteria Raw Environmental Damage that thres hold noise level forresidential areasandsettlementsamounted to55dB.The purpose of this study was to determine the characteristics of the traffic, the noise level of traffic, the perception of the population in Dalung Permai housing. Data collected by way of interviews with respondents and direct measurements in the field. Based on the data analysis it is known that the highest traffic volume during rush hour occurred in the morning (07.00 to 09.00) in the segment Jl. Tegal Luwih with volume vehicle as much as 21.599 vehicles, the segment Jl. Dalung Permai and segments Jl. Tegal Permai occurred in the afternoon (05.00 to 07.00) with a total volume of 22.450 and 17.587 vehicles. Instantaneous speed of the average of each type of vehicle ranges between 33-40 km per hour. The main sources of traffic noise is a four-stroke motorcycles with prosenatse average reached 91.61% of the total number of vehicles. The average noise level measured has exceeded the threshold setandar quality standard that ranged from 73.71 to 76.77 dB. In the segment Jl. Tegal Luwih, segments Jl. Tegal Permai and segments Jl. Dalung Permai give the perception that the level of traffic noise in a residential area is disturbing level of comfort.