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

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.

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).


2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Mariangela Vallone ◽  
Felice Pipitone ◽  
Salvatore Amoroso ◽  
Pietro Catania

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.


Akustika ◽  
2021 ◽  
pp. 62-67
Author(s):  
Menino Allan S.M. Peter Tavares

Experience of Transcendence’ is acoustically characterized in Pfarrkirche St Michael, Steyr using trained participants’ feedback during live organ rendition of Johann Sebastian Bach’s ‘TOCCATA’. Transcendental experiences of ‘awe’, ‘deeper understanding’ and ‘tranquility’ were acoustically derived and termed as ‘Acoustically Transcendent Awe’ (ATAWE), ‘Acoustically Transcendent Intelligibility’ (ATINT), and ‘Acoustically Transcendent Tranquility’ (ATTRANQ). In this study, ‘Acoustically Transcendent Intelligibility’ (ATINT) and ‘Acoustically Transcendent Tranquility’ (ATTRANQ) showed significant multiregressions with subjective acoustical qualities of the space (R2=0.99; p=0.01) and (R2=0.99; p=0.04) respectively. Instantaneous, statistical and percentile sound levels during ambient noise and during live performances were recorded at different listening zones. Background Noise Levels (LA90) between 76dB-82dB indicated congregational and choir space as optimally loud (without any need for electro-acoustical support) and sanctuary (with LA90 value of 56.8dB) as needing support, for performance and listening. Acoustically ranscendent Intelligibility (ATINT) was found significantly predictable from Subjective Acoustical Quality of Silence from Background Noise (SAQSNOIS) (p=0.05) and from Background Noise Level (LA90) (p=0.05). Perception of optimal Reverberance (SAQREV) in the Choir Loft provides good ambience for choir and musicians. These significant relationships between Acoustical Transcendence Impressions, Subjective Acoustical Qualities and Sound Levels can serve as part of Pfarrkirche St Michael’s unique intangible heritage.


PEDIATRICS ◽  
1975 ◽  
Vol 56 (4) ◽  
pp. 617-617
Author(s):  
Gōsta Blennow ◽  
Nils W. Svenningsen ◽  
Bengt Almquist

Recently we reported results from studies of incubator noise levels.1 It was found that in certain types of incubators the noise was considerable, and attention was called to the sound level in the construction of new incubators. Recently we had the opportunity to study an improved model of Isolette Infant Incubator Model C-86 where the mechanical noise from the electrically powered motor has been partially eliminated. With this modification it has been possible to lower the low-frequency sound levels to a certain degree in comparison to the levels registered in our study.


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.


2005 ◽  
Vol 24 (6) ◽  
pp. 33-37 ◽  
Author(s):  
Charlene Krueger ◽  
Susan Wall ◽  
Leslie Parker ◽  
Rose Nealis

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.


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.


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 ◽  
Vol 29 (3) ◽  
Author(s):  
Ngudi Tjahjono ◽  
Imam Hanafi ◽  
Latipun Latipun ◽  
Suyadi Suyadi

Noise due to motorized vehicles is a major problem in urban areas which can interfere with physiological and psychological health. This study aims to determine the extent of noise levels outside and inside the house around the function of different roads in Malang City, East Java, Indonesia. The study was conducted by measuring the traffic noise level using a sound level meter. Measurements were taken in the afternoon between 16.00-21.00 during the peak of heavy traffic and outside working hours when residents were already at home. Statistical Student’s t-test analysis was used to test differences in the average noise level outside and inside the house on each road function. Variance analysis was used to compare noise levels around primary arterial roads, secondary arteries, primary collectors, secondary collectors, primary local, and secondary local. From the measurement results, it is known that the noise due to motorized vehicles is 84.28 dB on average. This exceeds the threshold based on the Decree of the State Minister for the Environment Number 48 of 1996. There was a significant difference in noise level between outside and inside the house on each road function. There was no significant difference in noise level between the functions of the road segments both outside and inside the house. The results of the study concluded that the traffic noise level at 16:00 to 21:00 hours on all roads that were targeted for research exceeds the national threshold. It is recommended that the level of traffic noise around roads in the city of Malang can be reduced to minimize the negative impact on physiological and psychological health.


2004 ◽  
Vol 31 (4) ◽  
pp. 533-538 ◽  
Author(s):  
Saad Abo-Qudais ◽  
Arwa Alhiary

The main objective of this study was to evaluate the variation in traffic equivalent noise levels as distance from the road intersection increases. To achieve this objective, traffic volume and equivalent noise level were monitored at 40 signalized intersections in Amman, the capital of Jordan. An integrated sound level meter (ISLM) was used to measure 1 min equivalent noise level along all approaches of the evaluated intersections. A total of 3326 noise measurements were performed. The collected data were analyzed to evaluate the variation of noise levels as distance from the intersection increases. The results indicated that equivalent noise levels were significantly affected by distance from the signal stop line. The equivalent noise levels at distances 50 and 100 m from the intersection were found to be 1.5 to 2.0 dB less than those at 0 m. While at 200, 250, and 300 m from the intersection, the monitored equivalent noise levels were found to be 3.8 to 4 dB higher than that at 0 m. At distances farther than 250 m, the measured equivalent noise levels tend to keep constant value of equivalent noise level as distance increased.Key words: noise, traffic, intersection, environment, pollution.


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