scholarly journals An Assessment of the Impact of Helicopter Noise: Case Study of Mgbuoshimini Community Nigeria

Author(s):  
OF Orikpete ◽  
◽  
DRE Ewim ◽  

With the projected growth in demand for commercial aviation, it is anticipated that there will be an increased environmental impact associated with noise, air quality, and climate change. Against this backdrop, the noise levels experienced by the residents of Mgbuoshimini Community due to helicopters takeoff and landing were studied. The study was carried out for 14 days at three different locations using a Class 2 Optimus sound level meter from 7am to 5pm daily. Analysis involved the equivalent noise levels, statistical measures for the background noise, aircraft flyover noise as well as the Noise Gap Index (NGI) . It was found that the equivalent noise levels of the background noise and aircraft flyover noise range from 67.7 dBA to 72.4 dBA and 88.4 dBA to 88.6 dBA respectively. The peak background noise and aircraft flyover noise ranged from 69.17 dBA to 79 dBA and 93.2 dBA to 94.8 dBA respectively. These values exceeded the recommended value of 60 dBA for residential areas. Two models to determine the NGI for both low noise areas and high noise areas were developed. A correlation coefficient of 0.70 and 0.88 were obtained between the actual and predicted values of NGI for both low and high noise areas. Therefore, it is recommended that buildings should be adequately insulated by use of noise-absorbing materials. Furthermore, environmentally friendly (quieter) aircrafts should be used by the airline company operating in that area

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P160-P160
Author(s):  
Angela P Black ◽  
James D Sidman

Objectives To demonstrate that neonatal ventilators produce high noise levels through bone conduction (BC) via endotracheal tubes, as well as air conduction (AC) from ambient noise. Methods A sound level meter was used to measure the noise levels 4 feet from the ventilator and in direct contact at the end of a balloon attached to the ETT to simulate the noise presented to the infant. 3 commonly used neonatal ventilators (Sensormedics 3100A, VIP Bird and Bunnell Jet) were examined. Results Noise levels were significantly higher (6 – 14 dB) at the end of the ETT than 4 ft from the ventilator for all ventilators studied. Conclusions Previous studies have shown high ambient noise levels in NICUs, but have failed to address the actual noise presented to the infant. ETT transmission of noise as a direct bone stimulus through the skull has been overlooked. This study has shown that high noise intensities are being presented not only as AC, but as BC to the infants though the ETT. This study demonstrates, therefore, that ear protection alone will not save these at-risk infants from hearing damage. More must be done to decrease noise exposure and develop quieter machines.


2018 ◽  
Vol 250 ◽  
pp. 02006
Author(s):  
Zaiton Haron ◽  
Darus Nadirah ◽  
Supandi Mohamad Afif ◽  
Yahya Khairulzan ◽  
Nordiana Mashros ◽  
...  

Transverse rumble strips (TRS) are commonly being installed to alert the drivers through sound and vibration effects. The sound produced affects the existing traffic noise level which caused noise annoyance to the nearby residents. This study aims to assess the traffic noise due to TRS at residential areas by determining the roadside noise levels, traffic and road characteristics and evaluating the relationship between these parameters. Middle overlapped (MO), middle layer overlapped (MLO) and raised rumbler (RR) TRS profiles with same thickness were selected. The measurements of roadside noise levels and skid resistance were conducted using sound level meter (SLM) and British pendulum tester (BPT) respectively. Traffic characteristics were evaluated using previous data measured using automatic traffic counter (ATC). In overall, MLO produced highest roadside noise levels with increase of 20.5dBA from baseline. Generally, the increase of roadside noise level due to TRS is strong with speed, weak to medium with skid resistance of TRS and no relationship with traffic volume. Based on three TRS profile types, MLO is not suitable to be installed on the roadways adjacent to the residential areas as the increase of roadside noise level is significant which is more than 5dBA compared to MO and RR.


Author(s):  
Menekse Salar ◽  
M. Fehmi Capanoglu ◽  
Anjaneya Bandekar ◽  
Richard F. Sesek

Excessive noise is a global occupational health hazard with considerable social and physiological impact, including noise-induced hearing loss (NIHL) (Nelson et al., 2005). Noise is one of the most common occupational hazards in American workplaces. This study was performed in the Occupational Safety and Ergonomics Program’s Biomechanics Laboratory at Auburn University. The main purpose of this study was to compare the noise levels made by different air nozzles actually used by a bakery facility to nozzles whose manufacturers purported that they produce significantly less noise. Noise levels were determined using a sound level meter, which was positioned at ear level at distances of 5 and 10 feet. At the factory, air pressure (~100 psi) was used to push product downstream and to speed product cooling. The nozzles used were simple pipes or traditional air nozzles with side venting, but not of a “low noise” design. Two nozzles used by the factory were compared to three quieter nozzles. Nozzles were tested for both noise level and for air pressure (pushing force).


Author(s):  
Donguk Lee ◽  
Woojae Han

This study measures the noise levels in a baseball stadium and analyzes baseball fans’ attitude of effect of recreational noise exposure on their hearing. In the baseball stadium, noise levels were measured in four seating sections using a sound level meter during the games. The LAeq average of the 16 measures produced 91.7 dBA, showing a significantly high noise level in the red and navy sections. As a function of frequency by LZeq analysis, the noise levels were significantly higher in low frequencies than other frequencies. For the survey sample, 688 randomly selected participants completed a 16-question survey on their noise exposure during the game and on the potential risk of hearing loss. Despite the very high noise levels, 70% of the respondents preferred sitting in either the red or the navy section to be closer to the cheerleaders and to obtain a good view. Most respondents reported that they did not consider wearing earplugs, and one-third experienced hearing muffled speech after the game. We conclude that the noise levels in baseball stadiums are high enough to cause hearing damage and/or tinnitus later, but expect these results to improve public education regarding safe noise exposure during popular sports activities.


2021 ◽  
Vol 43 (4) ◽  
pp. 230-240
Author(s):  
Md. Abdul Aziz ◽  
Ahasanul Karim ◽  
Md. Mehedi Hassan Masum ◽  
Kazi Kader Newaz

Objectives : Noise pollution in Chittagong City of Bangladesh is a big concern because of huge population growth and urbanization. The objective of the study was to evaluate and mapping the noise levels in twelve locations of this city at different periods.Methods : Noise level data were collected at various locations by a precision grade sound level meter and the noise pollution parameters (Lmin, LAeq,2h and Lmax) were calculated. Furthermore, the noise pollution maps of Chittagong City were developed using geographical information system to address the locations which are prone to the environmental hazards.Results and discussion : The study revealed that the average noise levels were 64.6, 76.9, and 75.5 dB(A) for residential, commercial and silence zones, respectively. The interpolated noise maps showed that noise environment of this city was unsatisfactory, especially, in the areas of New Market, Nasirabad, and Bawa School & College were exposed to high noise pollutions. The afternoon and evening periods were experiencing higher noise pollution in the commercial and silence zones than the morning period of the day.Conclusions : The study suggests that the noise levels are above the acceptable limit and hence urgent measures should be taken into consideration to control the level of noise pollution in the city.


Author(s):  
Denis G. Karczub ◽  
Fred W. Catron ◽  
Allen C. Fagerlund

In a blow-down situation as might occur at a natural gas processing facility, noise levels are very high and significantly exceed the noise levels one would normally associate with a control valve. As the blow-down operation is an infrequent event, this may be permissible but requires consideration of the duration of these high noise levels to ensure that occupational noise exposure limits and acoustic fatigue limits are not exceeded. Tests of noise levels due to an 8-inch control valve in a 12-inch pipeline under blow-down conditions are compared here with noise level predictions based on the IEC standard. Consideration is also given to the impact of placing an orifice plate downstream of the control valve as is often done to reduce pressure drop across the valve in the expectation that control valve noise levels will be reduced. Simple orifice plates often installed by plant operators to achieve this goal are shown to have an adverse impact, and it is shown that a multi-hole diffuser or low-noise control valve should instead be used.


2017 ◽  
Vol 42 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Satish K. Lokhande ◽  
Satyajeet A. Dhawale ◽  
Samir S. Pathak ◽  
Rakesh Gautam ◽  
Mohindra C. Jain ◽  
...  

Abstract Noise mapping is a well-established practice among the European nations, and it has been follow for almost two decades. Recently, as per guidelines of the Directorate General of Mines Safety (DGMS), India, noise mapping has been made mandatory in the mining expanses. This study is an effort to map the noise levels in nearby areas of mines in the northern Keonjhar district. The motive of this study is to quantify the existing A-weighted time-average sound level (LAeq,T ) in the study area to probe its effects on the human dwellings and noise sensitive areas with the probability of future development of the mines, roads, and industrial and commercial zone. The LAeq,T was measured at 39 identified locations, including industrial, commercial, residential, and sensitive zones, 15 open cast mines, 3 major highways, and 3 haulage roads. With the utilisation of Predictor LimA Software and other GIS tools, the worked out data is mapped and noise contours are developed for the visualisation and identification of the extent and distribution of sound levels across the study area. This investigation discloses that the present noise level at 60% of the locations in silence and residential zone exposed to significantly high noise levels surpasses the prescribed limit of Central Pollution Control Board (CPCB), India. The observed day and night time LAeq, T level of both zones ranged between 43.2-62.2 dB(A) and 30.5-53.4 dB(A), respectively, whereas, the average Ldn values vary between 32.7 and 51.2 dB(A). The extensive mobility of heavy vehicles adjoining the sensitive areas and a nearby plethora of open cast mines is the leading cause of exceeded noise levels. The study divulges that the delicate establishments like schools and hospitals are susceptible to high noise levels throughout the day and night. A correlation between observed and software predicted values gives R2 of 0.605 for Ld, 0.217 for Ln, and 0.524 for Ldn. Finally, the mitigation measure is proposed and demonstrated using a contour map showing a significant reduction in the noise levels by 0-5.3 dB(A).


2021 ◽  
Vol 263 (1) ◽  
pp. 5114-5124
Author(s):  
Thulan Nguyen ◽  
Tran Thi Hong Nhung Nguyen ◽  
Bach Lien Trieu ◽  
Makoto Morinaga ◽  
Yasuhiro Hiraguri ◽  
...  

The travel restrictions caused by the epidemic outbreak in early 2020 worldwide have caused many changes in all aspects of life, especially in the acoustic environment. This study examines the impact of this environmental change at Tan Son Nhat International Airport (TSN), the largest airport in Vietnam, by comparing the situations before and after the airport stopped operating all international flights in March 2020. The after-the-change survey was conducted in 2 phases, June and September 2020, three months and six months after the stop decision. The number of flights observed in August 2019 was 728; this number is 413 and 299 for the two surveys in 2020. The range of noise levels estimated for 12 sites around TSN decreased from 63-81 dB in 2019 to 32-67 dB in June 2020 and 33-69 dB in September 2020. At the same aircraft noise level, the percentage of highly annoyed (% HA) and the percentage of insomnia (%ISM) in the 2020 survey are higher than those in the 2019 survey. The comparison results of reaction to noise before and after the TSN's noise change indicated an increase in negative responses to noise might happen in the increased noise and reduced noise situation.


2020 ◽  
Vol 121 ◽  
pp. 580-588 ◽  
Author(s):  
María del Carmen Pardo-Ferreira ◽  
Juan Carlos Rubio-Romero ◽  
Fuensanta Carmen Galindo-Reyes ◽  
Antonio Lopez-Arquillos

Author(s):  
Ravinder Thaper ◽  
Murray Gibson ◽  
Mathew Reed ◽  
Wallace Morris ◽  
Aravind Reddy Putta

This study aims to assess using a smartphone app (DecibelX), as a noise measuring alternative to the more costly traditional use of measuring noise levels with a Sound Level Meter (SLM). The study compares the accuracy of the app to readings taken with a SLM and dosimeter, and also evaluates the app’s performance for pure tone and narrow band noise. And a usability study identifies strengths and weaknesses related to usability of the app.


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