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Wyszukujesz frazę "Sound Pressure Level" wg kryterium: Temat


Tytuł:
Effects of Acoustic Treatment on Music Teachers’ Exposure to Sound
Autorzy:
Kozłowski, E.
Młyński, R.
Powiązania:
https://bibliotekanauki.pl/articles/177728.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
music teachers
sound pressure level
acoustic treatment
Opis:
In this study, music teachers’ exposure to sound was tested by measuring the A-weighted equivalent sound pressure level (SPL), the A-weighted maximum SPL and the C-weighted peak SPL. Measurements were taken prior to and after acoustic treatment in four rooms during classes of trumpet, saxophone, French horn, trombone and percussion instruments. Results showed that acoustic treatment affects the exposure of music teachers to sound. Daily noise exposure levels (LEX, 8 h) for all teachers exceeded a limit of 85 dB while teaching music lessons prior to room treatment. It was found that the LEX, 8 h values ranged from 85.8 to 91.6 dB. The highest A-weighted maximum SPL and C-weighted peak SPL that music teachers were exposed to were observed with percussion instruments (LAmax = 110.4 dB and LCpeak = 138.0 dB). After the treatments, daily noise exposure level decreased by an average of 5.8, 3.2, 3.0, 4.2 and 4.5 dB, respectively, for the classes of trumpet, saxophone, French horn, trombone and drums, and did not exceed 85 dB in any case.
Źródło:
Archives of Acoustics; 2014, 39, 2; 159-163
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Musician’s Earplugs on Sound Level and Spectrum During Musical Performances
Autorzy:
Kozłowski, E.
Żera, J.
Młyński, R.
Powiązania:
https://bibliotekanauki.pl/articles/90990.pdf
Data publikacji:
2011
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
earplugs
hearing protection
noise
sound pressure level
musicians
Opis:
In this study, change in A-weighted and 1/3-octave sound pressure levels (SPLs) was used to assess the influence of wearing earplugs by musicians on their musical performances. Seven soloists and 3 music assembles performed 4 pieces of music with musician’s earplugs donned and doffed. They used silicon custom moulded earplugs with acoustic filters designed to attenuate sound by 9, 15 or 25 dB. Results showed that the use of earplugs affected the sound level and the spectrum of played sounds. This effect was the greatest for brass players. The difference between SPLs in high-frequency 1/3-octave bands and A-weighted SPLs with and without earplugs exceeded 5 and 15 dB, respectively. Similar changes for woodwind, percussion and string instruments were less noticeable than for brass instruments; they were more than 5 dB for 1/3-octave spectra and no more than 2 dB for A-weighted SPL.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2011, 17, 3; 249-254
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Construction Changes in the Teeth of a Gear Transmission on Acoustic Properties
Autorzy:
Wieczorek, A.
Powiązania:
https://bibliotekanauki.pl/articles/90168.pdf
Data publikacji:
2012
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
gear
tooth height
gear contact ratio
sound pressure level
Opis:
This paper presents results of experimental research on the acoustic properties of gear wheels with high-profile teeth with differentiated tooth height. Those results showed that gear transmissions with high-profile teeth have the best acoustic properties, with the value of the transverse contact ratio εα ≈ 2.0. They also showed that a reduction in tooth height, and thereby in contact ratio, increased the sound pressure level.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2012, 18, 4; 499-507
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of noise transmission of a machine tool enclosure
Autorzy:
Bleicher, Friedrich
Reichl, Christoph
Linhardt, Felix
Wimberger, Peter
Habersohn, Christoph
Krall, Stephan
Powiązania:
https://bibliotekanauki.pl/articles/99968.pdf
Data publikacji:
2019
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
sound pressure level
machine enclosure
noise transmission
acoustic grid
Opis:
Machine tools are highly integrated mechatronic systems consisting of dedicated mechanic design and integrated electrical equipment – in particular drive systems and the CNC-control – to realize the complex relative motion of tool towards work piece. Beside the process related capabilities, like static and dynamic stiffness as well as accuracy behavior and deviation resistance against thermal influence, safety aspects are of major interest. The machine tool enclosure must fulfill multiple requirements like retention capabilities against the moving parts of broken tools, lose work pieces or clamping components. In regular use, the noise emission have to be inhibited at the greatest possible extent by the machine tool enclosure. Nevertheless, the loading door and the moving parts of the workspace envelope are interfaces where noise transmission is harder to be avoided and therefore local noise emissions increase. The aim of the objective investigation is to analyse the noise emission of machine tools to determine the local noise transmission of a machine tool enclosure by using arrays of microphones. By the use of this measuring method, outer surfaces at the front, the side and on the top of the enclosure have been scanned. The local transient acoustic pressures have been recorded using a standard noise source placed on the machine table. In addition, an exemplary manufacturing process has been performed to analyse the frequency dependent location resolved sound emissions.
Źródło:
Journal of Machine Engineering; 2019, 19, 3; 5-16
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Fast Method of Feature Extraction for Lowering Vehicle Pass-By Noise Based on Nonnegative Tucker3 Decomposition
Autorzy:
Wang, H.
Cheng, G.
Deng, G.
Li, X.
Li, H.
Huang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/177883.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vehicle pass-by noise
NTD
feature extraction
sound pressure level
Opis:
Usually, the judgement of one type fault of vehicle pass-by noise is difficult for engineers, especially when some significant features are disturbed by other interference noise, such as the squealing noise is almost simultaneous with the whistle in the exhaust system. In order to cope with this problem, a new method, with the antinoise ability of the algorithm on the condition by which the features are entangled, is developed to extract clear features for the fault analysis. In the proposed method, the nonnegative Tucker3 decomposition (NTD) with fast updating algorithm, signed as NTD_FUP, can find out the natural frequency of the parts/components from the exhaust system. Not only does the NTD_FUP extract clear features from the confused noise, but also it is superior to the traditional methods in practice. Then, an aluminium-foil alloy material, which is used for the heat shield for its lower noise radiation, replaces the aluminium alloy alone. Extensive experiments show that the sound pressure level of the vehicle pass-by noise is reduced 0.9 dB(A) by the improved heat shield, which is also considered as a more lightweight design for the exhaust system of an automobile.
Źródło:
Archives of Acoustics; 2017, 42, 4; 619-629
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Overview of the Noise Levels Measured in Industrial Facilities in Serbia and Implemented Methods of Protection
Autorzy:
Luburić, Uranija Kozmidis
Samardžić, Selena
Lakatoš, Robert
Mihailović, Aleksandra
Veselinović, Milka
Powiązania:
https://bibliotekanauki.pl/articles/176762.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
noise
industry
SPL
sound pressure level
frequency analysis
noise protection
Opis:
Noise is one of the most significant factors which not only disturbs working conditions, but has a large impact on workers’ health. This problem has existed in industries since the beginning and, despite technical and other solutions, it has not been solved. There is a large number of papers, supported with very detailed analyses, that investigate noise levels in industry or contain questionnaires about the impact of noise on workers’ overall health and work abilities. The purpose of this paper is to contribute to the global picture of sustainability and the development of strategies for improving the quality of working environment, with special attention to the generation of noise in different production processes in thirteen different industries in Novi Sad, Serbia. The paper also seeks to examine the advantages and drawbacks of the implemented protective methods and to provide some recommendations for their better implementation in order to contribute to solving this significant problem of today.
Źródło:
Archives of Acoustics; 2020, 45, 3; 499-510
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Urethane Foam Cushioning on Structure-Borne Sound Transfer by a Slab with Panel Flooring
Autorzy:
Mu, R.
Toyoda, M.
Takahashi, D.
Powiązania:
https://bibliotekanauki.pl/articles/176817.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
urethane foam
direct pasted flooring
floor impact sound
sound pressure level
sound insulation performance
Opis:
Urethane foam mattresses are commonly used as cushioning when placing panel flooring on the floor slab of a building. Urethane foam consists of elastic fibres with pores. Both elements can affect the performance of the insulation against impact sounds. However, these effects have not yet been detailed, and they may change if the material properties or constitution of the fibres and pores in the cushioning change. In this paper, we propose an analytical model for use in evaluating the performance of insulation against floor impact sound. This model was used to examine the contribution of the pores versus the elastic fibres to wave transmissions from the flooring surface to the slab. The results reveal that the constitution of the foam (either open or closed cells of pores) and the thickness and hardness of the cushion layer strongly affect the sound insulation performance of the floor.
Źródło:
Archives of Acoustics; 2016, 41, 1; 99-106
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research of noise in tractor K700 cabin
Autorzy:
Pobedin, A. V.
Dolotov, A. A.
Iskaliev, A. I.
Potapov, P. V.
Powiązania:
https://bibliotekanauki.pl/articles/242604.pdf
Data publikacji:
2015
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
capital repair
sound pressure level
noise total level
noise spectre
tractor
cabin
measuring
Opis:
This paper briefly describes method of noise-measuring tractor’s K700 cabin, obtained noise spectres were analysed and recommendations based on these results for noise decreasing in cabin K700 are proposed. Air noise penetrates into the tractor’s K700 cabin through panels, enclosures, apertures, chinks etc. Structural noise in the cabin is caused by vibrations transfer from sources along tractor frame through vibration isolators to cabin walls and carcass. At that, the main noise sources are engine case, air system, exhaust system, engine cooling system fan and also transmission case located under cabin floor. Every panel in the cabin has own intensity of sound waves radiation and thus contributes to forming of the sound field on the operator workspace. Therefore, it is important to know the sound pressure level near every panel into the cabin. It was state that at low frequencies, noise from left windshield prevails. In addition, in high frequencies bands the highest sound pressure issues from partition between engine area and cabin. Noise spectres have sound pressure peaks in bands with centre frequencies. Total noise level perceived by operator in tractor cabin is less during tractor motion on dirt road without aggregate than during its work with seeding machine on field prepared for winter grasp. At that, partition between engine area and cabin contributes greatly. Thus, for integrated noisiness, reducing in the tractor cabin sound isolation of partition between engine area and cabin should be increased and also sound isolation of windshields located closely to exhaust pipe has to be improved. To decrease low-frequency noise optimization of tractor cabin vibration isolation system need to be performed.
Źródło:
Journal of KONES; 2015, 22, 1; 261-264
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustic Analysis Using Sound Level Meter to Determine the Period of Usage of the Spindle Bearing of a Radial Drilling Machine
Autorzy:
Charles, S.
Vijaya, Joslin D.
Powiązania:
https://bibliotekanauki.pl/articles/176769.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustical condition monitoring
radial drilling machine
spindle bearing
sound level meter
sound pressure level
sound muting transducer
Opis:
The condition monitoring techniques like acoustic emission, vibration analysis, and infrared thermography, used for the failure diagnosis of bearings, require longer processing time, as they have to per form acoustical measurement followed by signal processing and further analysis using special software. However, for any bearing, its period of usage can be easily determined within an hour, by measuring the bearing sound, using sound level meter (SLM). In this paper the acoustical analysis of the spindle Bering of a radial drilling machine was performed using SLM, by measuring the sound pressure level of the bearing in decibels, for different frequencies, while muting all the other noises. Then using an experimental set up, two database readings were taken, one for new bearing and the other for completely damaged bearing, both are SKF6207, which itself is the spindle bearing. From these three sets of sound pressure level readings, the period of usage of the spindle bearing, was calculated using an interpolation equation, by substituting the life of the bearing from the manufacturer’s catalogue. Therefore, for any machine with a SKF6207 bearing, its usage time can be estimated using the database readings and one measurement on that machine, all with the same speed.
Źródło:
Archives of Acoustics; 2019, 44, 3; 505-510
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena emisji hałasu maszyn na podstawie poziomów ciśnienia akustycznego emisji
Assessment of noise emission of machines on the basis of emission sound pressure levels
Autorzy:
Pleban, D.
Powiązania:
https://bibliotekanauki.pl/articles/180112.pdf
Data publikacji:
2005
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
hałas maszyn
poziom ciśnienia akustycznego emisji
noise
machine noise
sound pressure level
Opis:
Zgodnie z dyrektywą europejską 98/37/EC dotyczącą maszyn poziomy ciśnienia akustycznego emisji powinny być uwzględnione podczas oceny akustycznej maszyny. Metody wyznaczania tych poziomów są określone w serii norm europejskich EN ISO 11200. W artykule przedstawiono wyniki badań eksperymentalnych dotyczących wyznaczania poziomów ciśnienia akustycznego emisji hałasu maszyn.
According to European Directive 98/37/EC relating to machinery, emission sound pressure levels must be taken into consideration while carrying out an acoustic assessment of machinery. The European Standard series EN ISO 11200 specifies methods for determining emission sound pressure levels. This paper presents the results of experimental tests concerning determination of the emission sound pressure levels of different machines.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2005, 4; 6-9
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hałas maszyn- znormalizowane metody wyznaczania poziomu ciśnienia akustycznego emisji
Autorzy:
Pleban, D.
Augustyńska, D.
Powiązania:
https://bibliotekanauki.pl/articles/180215.pdf
Data publikacji:
2000
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas maszyn
normalizacja
poziom ciśnienia akustycznego emisji
machine noise
normalisation
sound pressure level
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2000, 10; 6-9
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical and Computational Acoustic Modelling of Side Outlet Muffler and Its Extension in the Modelling of Tapered Side Outlet Muffler
Autorzy:
Vishwakarma, Sandeep Kumar
Pawar, Jayappa
Powiązania:
https://bibliotekanauki.pl/articles/31339955.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
1-D analysis
finite element analysis
FEA
sound pressure level
transfer matrix
transmission loss
Opis:
Mufflers are popular in the suppression of noise levels coming from various machinery. The most common parameters for the evaluation of the performance of mufflers are transmission loss, noise level, and insertion loss. The transmission loss is evaluated for tapered side outlet muffler using finite element analysis without considering the fluid-structure interaction. This study includes analytical modelling and acoustic modelling of the side outlet muffler and transmission loss is in excellent agreement with the reference paper. The feasibility of the acoustic model is also verified with the experimental work on simple expansion chamber muffler. The same finite element analysis is extended for the tapered side outlet muffler. The transmission loss of the tapered side outlet muffler in the given frequency range is found 8.96 dB better than the side outlet muffler. The acoustic pressure level and sound pressure level contours for the tapered side outlet muffler give a clear picture of wave propagation inside the muffler. The effect of the cut-off frequency on the transmission loss of the tapered side outlet muffler can be seen from the contours. This study can be helpful in the determination of the performance of the mufflers in terms of transmission loss, the performance of mufflers above cut-off frequency, and design improvements in the muffler to avoid the higher-order modes of the sound wave.
Źródło:
Archives of Acoustics; 2022, 47, 4; 491-499
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pomiary hałasu wytwarzanego przez źródła znajdujące się blisko ucha - na przykładzie zestawów słuchawkowych
Measurement of noise produced by sources close to an ear - on the example of headsets
Autorzy:
Kozłowski, Emil
Młyński, Rafał
Powiązania:
https://bibliotekanauki.pl/articles/31342462.pdf
Data publikacji:
2022
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
zestaw słuchawkowy
poziom dźwięku
manekin akustyczny
noise
headsets
sound pressure level
acoustic manikin
Opis:
W artykule przedstawiono wyniki pomiarów parametrów hałasu wytwarzanego przez zestawy słuchawkowe. Wyniki bezpośredniego pomiaru z zastosowaniem manekina akustycznego zostały skorygowane w taki sposób, aby otrzymane wartości odpowiadały warunkom pola swobodnego i można je było odnieść do obowiązujących w Polsce wartości kryterialnych oceny narażenia na hałas. W przypadku równoważnego poziomu dźwięku A wartości poprawki zostały wyznaczone według znormalizowanej metody, natomiast w przypadku maksymalnego poziomu dźwięku A i szczytowego poziomu dźwięku C zaproponowano własną metodę wyznaczania wartości tej poprawki. Zaprezentowane w artykule wyniki pomiarów potwierdziły, że w odniesieniu do badanych zestawów słuchawkowych, przy określonych ustawieniach układu wzmocnienia, nie wystąpiły przekroczenia wartości NDN oceny narażenia na hałas. Istnieje jednak możliwość przekroczenia progu działania w przypadku poziomu ekspozycji na hałas odniesionego do ośmiogodzinnego dobowego wymiaru czasu pracy. Ponadto pomiary wykazały, że wartości poprawki równoważnego poziomu dźwięku A, maksymalnego poziomu dźwięku A i szczytowego poziomu dźwięku C są do siebie zbliżone niezależnie od metody ich wyznaczania Wartości poprawki zależą zaś od zestawu słuchawkowego, który służy do odtwarzania sygnału testowego.
The article presents the results of measurements of noise parameters generated by headsets. The results of direct measurement carried out using an acoustic manikin were corrected so that the obtained values corresponded to the free-field conditions and could be referred to the criterion values of noise exposure assessment in Poland. In case of A-weighted equivalent sound pressure level, the correction value was determined according to the normalized method. However, in case of A-weighted maximum sound pressure level and C-weighted peak sound pressure level the own method of determination of this correction was proposed. The results of measurements presented in the paper showed that for the tested headsets, at the specific settings of gain level, no exceedance of the noise exposure limit values occurred. However, it is possible that the action value may be exceeded for daily noise exposure level. Moreover, the measurements showed that the correction values for the A-weighted equivalent sound pressure level, A-weighted maximum sound pressure level and C-weighted peak sound pressure, regardless of the method of their determination, are similar to each other. However, the correction values depend on the headset, which was used to play the test signal.
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2022, 7; 21-24
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of sound power level of machine by inverse method
Autorzy:
Piechowicz, Janusz
Powiązania:
https://bibliotekanauki.pl/articles/2146645.pdf
Data publikacji:
2021
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
inverse method
sound power
sound pressure level
sound measurement
metoda odwrotna
moc akustyczna
poziom ciśnienia akustycznego
pomiar dźwięku
Opis:
The paper presents the inverse method to estimate the sound power level of machines operated in industrial environments. Values of the partial sound power sources of machine components could be predicted based on the distribution of sound field parameters measured around the machine. Assigning partial sound power levels of machine components allows for the effective selection of efficient noise protection solutions for this machine. Measurements were carried out in an actual mechanical workshop. The multichannel measurement system for simultaneous recording of sound pressure levels and the angle of phase angle shift was used in measurements. Based on the determined the sound power of partial sources, the A-weighted sound pressure levels at the operator's workplace were determined.
Źródło:
Vibrations in Physical Systems; 2021, 32, 1; art. no. 2021113
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hałas maszyn – znormalizowane metody wyznaczania poziomu ciśnienia akustycznego hałasu
Autorzy:
Pleban, D.
Augustyńska, D.
Powiązania:
https://bibliotekanauki.pl/articles/179687.pdf
Data publikacji:
2000
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
hałas
hałas maszyn
normalizacja
poziom ciśnienia akustycznego emisji
noise
machines noise
normalisation
sound pressure level
Źródło:
Bezpieczeństwo Pracy : nauka i praktyka; 2000, 9; 5-8
0137-7043
Pojawia się w:
Bezpieczeństwo Pracy : nauka i praktyka
Dostawca treści:
Biblioteka Nauki
Artykuł

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