Influence of vehicle source directivity in Japanese and European outdoor sound prediction models under a semi-finite thick barrier configuration

2021 ◽  
Vol 263 (1) ◽  
pp. 5147-5153
Author(s):  
Takuya Oshima ◽  
Fumiya Takeda ◽  
Yumi Kurosaka
Keyword(s):  
Noise Level ◽  
Prediction Models ◽  
Combined Effect ◽  
Sound Emission ◽  
Sound Levels ◽  
Thick Barrier ◽  
Source Directivity

The Japanese ASJ RTN-Model 2018, European Harmonoise and CNOSSOS-EU outdoor sound prediction models are respectively known to have symmetric, asymmetric and omnidirectional sound emission directivities along front-back direction of the source vehicle. However, the influence of such difference in directivities to final predicted sound levels has not been investigated much. In this study, the influence is investigated using the ASJ Model and the Harmonoise under a configuration of semi-finite thick barrier along a source road. The configuration is an idealization of Japanese roadside buildings that have gaps in between, unlike European buildings that continuously extend over a whole urban block. Under the configuration, distribution of A-weighted sound levels around the end face of the barrier are computed with and without source directivity taken into account by each model. It is found from the results that the source directivity of the ASJ model makes little difference in the noise level distribution. In contrast, the source directivity of Harmonoise is found to make differences of 0.5-0.8 dB at right behind the barrier depending on vehicle running direction. However, a combined effect of source directivity and reflection at the end face is found to be negligible.

Elevated Sound Levels within a Busy NICU

2005 ◽  
Vol 24 (6) ◽  
pp. 33-37 ◽  
Author(s):  
Charlene Krueger ◽  
Susan Wall ◽  
Leslie Parker ◽  
Rose Nealis
Keyword(s):  
Preterm Infants ◽  
Noise Level ◽  
Sound Level ◽  
Behavioral Effects ◽  
Outcome Variable ◽  
Sound Levels ◽  
Main Outcome Variable

Purpose: Elevated sound levels in the NICU may contribute to undesirable physiologic and behavioral effects in preterm infants. This study describes sound levels in a busy NICU in the southeastern U.S. and compares the findings with recommended NICU noise level standards.Design: NICU sound levels were recorded continuously at nine different locations within the NICU. Hourly measurements of loudness equivalent (Leq) sound level, sound level exceeded 10 percent of the time (L10), and maximum sound level (Lmax) were determined.Sample: Sound levels were sampled from nine different locations within the NICU.Main Outcome Variable: Sound levels are described using the hourly, A-weighted Leq, L10, and Lmax.Results: The overall average hourly Leq (M = 60.44 dB, range = 55–68 dB), L10 (M = 59.26 dB, range = 55–66 dB), and Lmax (M = 78.39, range = 69–93 dB) were often above the recommended sound levels (hourly Leq <50 dB, L10 <55 dB, and 1-second Lmax <70 dB). In addition, certain times of day, such as 6–7 AM and 10 AM–12 noon, were noisier than other times of day.

scholarly journals Appraisal of Noise Level Dissemination Surrounding Mining and Industrial Areas of Keonjhar, Odisha: a Comprehensive Approach Using Noise Mapping

2017 ◽  
Vol 42 (3) ◽  
pp. 423-432 ◽  
Author(s):  
Satish K. Lokhande ◽  
Satyajeet A. Dhawale ◽  
Samir S. Pathak ◽  
Rakesh Gautam ◽  
Mohindra C. Jain ◽  
...  
Keyword(s):  
Noise Level ◽  
Sound Level ◽  
Noise Levels ◽  
Night Time ◽  
Noise Mapping ◽  
High Noise ◽  
Sensitive Areas ◽  
Sound Levels ◽  
Directorate General ◽  
Open Cast

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).

Excess noise reduction with ear protector applying mathematical algorithm: A case of medium density fiber industry

2020 ◽  
Vol 51 (7-9) ◽  
pp. 139-157
Author(s):  
Sohail Khan ◽  
Ishrat Noor ◽  
Tufail Habib ◽  
Muhammad Waseem
Keyword(s):  
Noise Reduction ◽  
Noise Level ◽  
Single Point ◽  
Reduction Rate ◽  
Excess Noise ◽  
Medium Density ◽  
Mathematical Algorithm ◽  
Average Value ◽  
Safe Level ◽  
Sound Levels

Consistent exposure to elevated sound levels results in noise health effects. The industrial environment represents a major source of such effects. There is significant variation in noise at different sections of such industries due to which most of the workers are exposed to these sounds at one or another level. In this study, a noise level measuring methodology is used for fixed and moving workers. This article introduces an algorithm for optimum selection of earmuff and earplug for different working places depending upon the exposure to noise. Medium density fiber industry is considered as a case for this study. It considers workers who are busy at a single point and face a consistent amount of noise as well as the workers who move and are exposed to a varying level of the noise. Noise level meters are used to measure the noise level at different points. At each point, the average value of the samples is taken. Based on the data collected, earmuff with high noise reduction rate is assigned to the workers closed to the machines. Implementation of the developed algorithm reduced the effect of noise on workers by 6.9%, 5%, and 16.3% for the chipper machine, pneumatic fan, and sanding machine, respectively, that were identified as the major source of noise at medium density fiber industry. This percentage reduction helped the workers to bring them to the optimum safe level of noise that is 85 dB and protect them from hearing loss severity due to frequency variations.

Assessing the Potential for Noise Complaints due to Backyard Chickens

2021 ◽  
Vol 263 (1) ◽  
pp. 5106-5113
Author(s):  
Charles Moritz
Keyword(s):  
Prediction Models ◽  
The United States ◽  
Sound Level ◽  
Sound Sources ◽  
Technical Literature ◽  
The Past ◽  
Common Complaint ◽  
Sound Levels ◽  
Chicken Breeds ◽  
Backyard Chickens

During the past decade, there has been tremendous growth in the popularity of backyard chickens in urban and suburban locations throughout the United States. While there are many advantages to raising chickens, their introduction has not gone without controversy. Noise has been a common concern during discussions of municipal ordnances and a common complaint against flock owners. There is very little data on the sound levels produced by chickens in the technical literature. What data is published is not appropriate for predicting sound levels at owners' property lines. In addition, the non-technical literature, social media, newspaper stories, etc. abounds with misinformation. To determine the sound power of various chicken breeds, the author has been measuring sound levels from birds in his flock. This data can then be compared to the sound level from other typical back yard sound sources, existing community annoyance prediction models, and records of noise complaints.

scholarly journals The Analysis of Noise Level on Saulkarsti Bypass, Latvia

2009 ◽  
Vol 3 (3) ◽  
pp. 135-141
Author(s):  
A. Zandberga ◽  
L. Lieplapa ◽  
D. Blumberga
Keyword(s):  
Noise Level ◽  
Time Frame ◽  
Experimental Measurements ◽  
Traffic Intensity ◽  
Sound Levels ◽  
Data Gaps ◽  
Sound Barriers ◽  
Permissible Levels ◽  
Short Time ◽  
Total Impact

The Analysis of Noise Level on Saulkarsti Bypass, Latvia The environmental impact assessment (EIA) is an acknowledged method in the world used for estimating the possible changes to the environment caused by proposed development activities, including the development of linear infrastructures. The EIA of planned projects for building or reconstruction of the motorways in Latvia are usually carried out in a short time frame, and therefore the data characterizing current environmental conditions sometimes are not of the best quality. These kind of data gaps cause an inaccurate prognoses on the possible changes to environmental quality after project implementation. Our research demonstrates that this was the case concerning the weak evaluation of sound levels on the Saulkrasti bypass. Within the framework of the EIA, the prognosis of sound levels was elaborated, prooving that, generally, the traffic sound will be within the officially permissible levels, although the problem points are recognized and the erection of sound barriers are proposed. After construction of bypass, however, the noise monitoring has not been carried out in order to verify whether the prognosis are true. In fact, the results of experimental measurements at four points on the Saulkrasti bypass showed the opposite - the noise level in the daytime (Ld) exceeded the acceptable value at all points of the measurements, including the places with installed sound barriers. The task of our experimental measurements on the bypass was also to find a correlation between the noise level and traffic intensity. The results showed that a correlation between these factors is weak, and the noise level is not directly dependant on traffic intensity, but on the total impact of several factors.

scholarly journals Noise risk assessment in a bottling line of a modern Sicilian winery

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Mariangela Vallone ◽  
Felice Pipitone ◽  
Salvatore Amoroso ◽  
Pietro Catania
Keyword(s):  
Noise Level ◽  
Sound Level ◽  
Wine Industry ◽  
Production Cycle ◽  
Working Capacity ◽  
Noise Levels ◽  
Test Conditions ◽  
Sound Levels ◽  
Class 1 ◽  
Plant Area

In wine industry, bottling is a phase of the production cycle characterized by high levels of noise mostly due to repeated collisions between the bottles. In Italy the Law Decree 81/2008 defined the requirements for assessing and managing noise risk, identifying a number of procedures to be adopted at different noise levels to limit workers exposure. This study aims at evaluating the equivalent and peak noise level inside the bottling plant area of a modern Sicilian winery. In particular, the influence of the working capacity (number of bottles produced per hour) on noise levels was evaluated. We considered three test conditions: T1 with working capacity of 4,000 bottles per hour, T2 with working capacity of 5,000 bottles per hour and T3 with working capacity of 6,000 bottles per hour. Fifteen measurement points were identified inside the bottling area. The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. The tests were performed in compliance with ISO 9612 and ISO 9432 regulations. The results show that as bottling plant working capacity increases, noise level increases. The measured sound levels exceed the limits allowed by the regulations in all the test conditions; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 95 dB(A) in test T3. In this case, the operator working along the bottling line is obliged to wear the appropriate Personal Protective Equipment.

Evaluation and Modeling of Traffic Noise in Berhampur City, India

2020 ◽  
Vol 19 (04) ◽  
pp. 2050044 ◽  
Author(s):  
A. K. Sahu ◽  
P. K. Pradhan ◽  
S. K. Nayak ◽  
M. Pradhan ◽  
C. R. Mohanty
Keyword(s):  
Noise Level ◽  
Urban Areas ◽  
Prediction Models ◽  
Human Life ◽  
Traffic Noise ◽  
Developed Countries ◽  
Noise Evaluation ◽  
Pressure Headache ◽  
Day By Day ◽  
Developing And Developed Countries

Traffic noise in urban areas is increasing day by day, owing to addition in the number of vehicles on road in developing and developed countries. The increase of noise level reduces the wellbeing of the exposed people. Exposure to high noise results in development of ill health including annoyance, high blood pressure, headache and other physiological and psychological problems. Noise not only affects the human life but also affects animals and birds in the ecosystem. In this experimental study, the evaluation of traffic noise in Berhampur city has been done. Eleven important locations covering the whole city were considered for traffic noise evaluation. Other than the evaluation of traffic noise, the well-known traffic noise prediction models have been tested here. It has been found that, in this situation, such established models do not function well and have a low coefficient of correlation value. A new befitting model has been formulated using multiple regression analysis to predict the traffic noise level and later on, it is also tested as well as validated at different locations.

scholarly journals INVESTIGATION INTO THE DEPENDENCE OF NOISE GENERATED BY STANDING CARS ON THE ENGINE POWER / STOVINČIŲ LENGVŲJŲ AUTOMOBILIŲ KELIAMO TRIUKŠMO PRIKLAUSOMYBĖS NUO VARIKLIO DARBINIO TŪRIO TYRIMAI

2012 ◽  
Vol 5 (4) ◽  
pp. 473-478
Author(s):  
Julius Gineika ◽  
Raimondas Grubliauskas
Keyword(s):  
Noise Level ◽  
Ambient Noise ◽  
Sound Level ◽  
Noise Measurement ◽  
Noise Levels ◽  
Sound Levels ◽  
Local Sources ◽  
Engine Testing ◽  
Engine Capacity ◽  
Engine Power

Ambient noise harms a number of citizens in Europe. The major sources of environmental noise are that generated by cars in streets, parking lots, railway lines and airports as well as noise from local sources (fans, transformers). According to the methodology for noise measurement, engine testing has been carried out. The conducted analysis has been focused on engine capacity and the distance between vehicles and equipment. Equivalent, maximum and minimum sound levels at different frequencies have been measured accepting that errors may range up to 2 %. Maximum sound level has been reached using the engine of 2000 cm3 petrol capacity. At a half-meter distance, the equivalent sound level reaches 89 dB(A), whereas the noise level decreases moving away from the car. The obtained results of tested cars disclose that according to engine capacity, the majority of the investigated cars are technically faulty and therefore significantly exceed noise levels. Santrauka Straipsnyje nagrinėjamas lengvųjų automobilių variklių skleidžiamas triukšmas bei jo poveikis aplinkai. Pateikiama triukšmo matavimo metodika ir eksperimentinis variklio sukelto triukšmo tyrimas. Ištirti penki automobiliai su skirtingais darbinio tūrio skirtingais atstumais varikliais: 1400 cm3 benzininis, 1500 cm3 dyzelinis, 1800 cm3 benzininis, 2000 cm3 benzininis ir 2500 cm3 dyzelinis. Variklio keliamo triukšmo tyrimas buvo atliktas, esant 1000 sūk./min., taip pat įvertinta, kurie automobiliai viršija leistinus triukšmo lygius. Buvo atlikti tyrimai esant 3000 sūk./min. (benzininiams varikliams) ir 3500 sūk./min. (dyzeliniams varikliams). Išmatuoti ekvivalentinis, maksimalus bei minimalus garso lygiai, taip pat garso lygiai, esant skirtingiems dažniams. Priimame prielaidą, kad paklaida gali svyruoti iki 2 %. Didžiausias garso lygis pasiektas 2000 cm3 benzininio variklio. Pusės metro atstumu ekvivalentinis garso lygis siekia 89 dB(A). Tolstant nuo automobilio, triukšmo lygis mažėja. Remiantis gautais rezultatais, galima daryti išvadą, kad vertinant pagal variklių darbinį tūrį daugelis tirtųjų automobilių yra techniškai netvarkingi ir stipriai viršija triukšmo lygius.

scholarly journals Noise exposure during orthopaedic surgery

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Ailin Razali ◽  
Hendy Putra Herman ◽  
Ahmad Hafiz Zulkifly
Keyword(s):  
Hearing Loss ◽  
Noise Level ◽  
Noise Exposure ◽  
Peak Level ◽  
Operating Theatre ◽  
Healthcare Personnel ◽  
Local Data ◽  
Screw Insertion ◽  
Sound Levels ◽  
Many Instruments

Introduction: There is serious concern on noise hazard in the operating theatre, especially in the orthopaedics field that requires usage of many instruments. However, local data on this noise exposure is rather limited. This study was conducted as a pilot study to investigate the noise exposure in orthopaedics theatre in a hospital in Kuantan, Pahang in June 2011. Methods: Several different orthopaedics theatres involving procedures that use powered instruments were investigated. Time recorded noise exposures were taken using a noise dosimeter throughout the surgeries worn by the surgeons. The peak noise level and the average noise exposure within 8 hours were determined, and compared with available health guidelines, namely the Factories and Machinery (Noise Exposure) Regulations 1989. Results: Six out of seven surgeries which include interlocking nail and plating of femur, Ilizarof insertion, total knee replacement and dynamic hip screw insertion of the femoral head were found to exceed 140 dB(A) for peak sound levels. The average noise exposure within 8 hours was below 85 dB(A) in all cases. Although the average noise level did not surpass the health guidelines, the peak level exceeding 140 dB(A) still carries risk for hearing loss. Conclusions: In conclusion, healthcare personnel in operating theatre were exposed to noise hazard for certain orthopaedics surgical procedures. Hence, proper noise management should be implemented to protect them from noise-induced hearing loss while maintaining the success and efficiency of the surgeries.

scholarly journals Noise Effects of Generator Sets at Construction Sites

2014 ◽  
Vol 3 (2) ◽  
pp. 12-17
Author(s):  
Elancheliyan Sellappan
Keyword(s):  
Noise Level ◽  
Noise Exposure ◽  
Work Group ◽  
Diesel Generator ◽  
Construction Sites ◽  
Noise And Vibration ◽  
Power Generators ◽  
Sound Levels ◽  
Work Area ◽  
Shift Length

Noise and vibration can be the cause of serious disturbance and inconvenience to anyone exposed to them and in certain circumstances noise and vibration can be a serious hazard to health, causing        permanent damage to hearing system. Noise exposure levels of construction workers are difficult to determine due to the day to-day variation in occupation and shift length of each worker and the itinerant and seasonal nature of the job. Nevertheless, it is clear that the construction worker is exposed to very high sound levels for considerable lengths of time. Different types and sizes of equipment's, machineries and tools are used by construction industries. Diesel Generator for power is a very important one among the equipment used in the construction industries, used in large numbers and as clusters and also located very near to the work area. The noise level produced by these generators is much higher than the permissible limit. But the construction work group took very little effort to avoid or minimize this noise level to permissible level. Many people even though they may not need electricity for their work got in and exposed in this zone of danger. At this site eight generators have been used by various working groups. This paper assesses the potential noise impacts associated with power generators used in construction activities of the DCT project site and the effective steps to control this noise. A 12-hour noise survey was conducted to establish background noise levels in the project area. DOI: http://dx.doi.org/10.3126/ijosh.v3i2.6145 

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