scholarly journals Comparison of Changes of Road Noise Level Over a Century Quarter: A Case Study of Acoustic Environment in the Mountainous City

2021 ◽  
Vol 22 (1) ◽  
pp. 139-150
Author(s):  
Magdalena Vaverková ◽  
Eugeniusz Koda ◽  
Małgorzata Wdowska
Urban Science ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 63
Author(s):  
Kimihiro Sakagami

This communication compares the previously reported results of the acoustic environment, mainly noise levels at a fixed point, in a quiet residential area in Kobe, Japan, under the declaration of the COVID-19 state of emergency in May 2020 with the results of two follow-up studies in the same area: subsequent follow-up noise measurements in June and July–August 2020, and the present results of measurements in September–October 2020. The results of the comparison among the above three measurements suggest that noise levels were lower during September-October 2020 than during the declaration of the state of emergency in May 2020. In the period from May to October 2020, the noise level was significantly higher in July and August of the same year due to the sound of cicadas, which are common in this area. This suggests that it is difficult to set the target values of the acoustic environment planning by referring to the low noise level at lockdown or similar measures in areas with large seasonal variations in acoustic environment. Although many case studies are necessary to obtain appropriate target values, one case study is presented in this communication to illustrate an example and discuss its difficulty.


2021 ◽  
Author(s):  
Kimihiro Sakagami ◽  
Midori Kusaka ◽  
Takeshi Okuzono ◽  
Shigeyuki Kido ◽  
Daichi Yamaguchi

There are various measures currently in place to prevent the spread of COVID-19; however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets, as including a hole-free panel is important to a possible droplet penetration. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings of the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. This time, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.


Author(s):  
Bhalchandra Puranik ◽  
Younes Shabany

The airflow management for multi-board rack-mount equipment has to meet certain requirements including a minimum air velocity over the boards, uniform air velocity from board to board and from front to rear, and fan redundancy. These requirements have to be met within certain size, noise level and reliability constrains. Several configurations are usually considered: “push” or pressurized system, “pull” or vacuum system, and “push-pull” system. The purpose of this article is to demonstrate the airflow management design process for the three system configurations mentioned above, and to compare their optimum designs with each other given a set of geometrical constraints such as the overall dimensions of the equipment chassis, the card cage, and the type and thickness of the air filter. The design process is explained as a case study involving a typical multi-board rack mounted telecommunication chassis.


Noise Mapping ◽  
2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Francesco Aletta ◽  
Jian Kang

AbstractIn the guidelines about the management of areas of good environmental noise quality recently published by the European Environment Agency (EEA) it is suggested to combine different methodologies, like noise mapping, sound level measurements and the soundscape approach. Such a recommendation has started to be recognised by a number of local authorities in Europe that are gradually integrating a holistic concept into their environmental noise policies. This research aimed to explore and demonstrate the possibility to integrate conventional noise mapping methods and soundscape methods in an actual urban redevelopment project. A case study was made using the Valley Gardens project in Brighton & Hove (UK). Different scenarios of sound-pressure level distributionswere simulated for both traffic sound sources (i.e. noise maps) and natural sound sources (i.e. sound maps). Additionally, individual responses about the sound environment of the place collected during an on-site question survey were used to implement soundscape maps.The overall picture revealed that the road traffic noise should be reduced, but also it is feasible that preferred sounds likewater features or birdsong could be introduced to make the sound environment more appropriate for the place. Generally, within the framework of this research, noise maps, sound maps and soundscape maps were used together to "triangulate" different layers of information related to the acoustic environment and the way it is perceived, providing a possible working procedure to consider for planners and policy-makers in the future.


ARCTIC ◽  
2020 ◽  
Vol 73 (3) ◽  
pp. 386-392
Author(s):  
Muthuraj Ashokan ◽  
Ganesan Latha ◽  
Ayyadurai Thirunavukkarasu

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.


2021 ◽  
Author(s):  
Kimihiro Sakagami ◽  
Midori Kussaka ◽  
Takeshi Okuzono ◽  
Shigeyuki Kido ◽  
Daichi Yamaguchi

There are various measures currently in place to prevent the spread of COVID-19; however, in some cases, these can have an adverse effect on the acoustic environment in buildings. For example, transparent acrylic partitions are often used in eating establishments, meeting rooms, offices, etc., to prevent droplet infection. However, acrylic partitions are acoustically reflective; therefore, reflected sounds may cause acoustic problems such as difficulties in conversation or the leakage of conversation. In this study, we performed a prototyping of transparent acrylic partitions to which a microperforated panel (MPP) was applied for sound absorption while maintaining transparency. The proposed partition is a triple-leaf acrylic partition with a single acrylic sheet without holes between two MPP sheets. The sound absorption characteristics were investigated by measuring the sound absorption in a reverberation room. As the original prototype showed sound absorption characteristics with a gentle peak and low values due to the openings on the periphery, it was modified by closing the openings of the top and sides. The sound absorption performance was improved to some extent when the top and sides were closed, although there remains the possibility of further improvement. This time, only the sound absorption characteristics were examined in the prototype experiments. The effects during actual use will be the subject of future study.


2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Jelena Božić ◽  
Predrag Ilić ◽  
Ljiljana Stojanović Bjelić

Noise pollution is one of the main environmental problems today.The main source of environmental noise is traffic noise, especially the noise of road vehicles. The continuing expansion of motorized transport in Europe and Republic of Srpska today, and especially the sharp increase in the use of private cars raises concerns about the health risks.The aim of the case study was to determine the noise level at the location „Borik“ in Banja Luka. The measured values indicate that the noise level in this street is alarming. This paper discusses health and well-being related impacts of traffic noise pollution as well as the economic and social benefits associated with its reduction. It summarizes the latest scientific evidence on the impact of road traffic-induced noise on physical and mental health as a reaction to the high level of traffic noise risks. According to the scientific evidence, road traffic is the main source of noise pollution in Europe that cause harmful health such as impaired communication and disturbed sleep, as well as adverse after effects such as fatigue and decreased performance, annoyance, hearing impairment, ischemic heart disease and hypertension. The effects of unhealthy noise level are reflected on living and working conditions, consequently affecting the economy.This paper highlights economic implications and health benefits linked to cross-functionalities in the process of noise reduction in urbanism, architecture and vehicle design and methods for its evaluation. Cost-benefit analysis would be a pivotal decision-making tool for the city road traffic and land-use decisions. Economic valuation is about identifying all preferences and translating them into a money measure, to create a common denominator for comparing the pros and cons. Any decision implicitly include a money value into health effects. A holistic approach is crucial, considering the various health and economic consequences together.


2021 ◽  
Vol 7 (3) ◽  
pp. 560-574
Author(s):  
Mohamed N. Younes ◽  
Ali Z. Heikal ◽  
Akram S. Kotb ◽  
Haytham N. Zohny

The noise levels inside metro units are considered a significant problem that makes passengers suffer from severe damage, especially for those who use the metro periodically. This research evaluates the acoustic environment inside the metro car and studies factors affecting the noise levels inside metro units and developing models for estimate noise in the metro unit while moving between stations. Greater Cairo Metro (GCM) Line 1 has been selected as a case study. A sound level meter was used to measure the equivalent sound level in dBA and evaluate the noise inside metro units. The results indicate that the noise levels are unacceptable compared with the international noise exposure standards. The highest measured noise level inside metro units is 91.2 dBA. These unacceptable noise levels led to more investigation of factors that may affect noise levels inside metro units. Other data have been collected, such as the speed of the train and the track alignment details. The results showed that the noise increases with the increase of the train speed until the speed reaches a specific value, then it decreases depending on the maintenance status and the train type. In addition, the noise levels through curved underground tracks are higher than the levels along straight surface tracks by 18 dB(A). Doi: 10.28991/cej-2021-03091674 Full Text: PDF


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