scholarly journals ENVIROMENTAL ASPECTS OF NOISE ASSESSMENT AND REGULATION IN THE DESIGN OF PORT COMPLEXES IN RUSSIA

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 72-78
Author(s):  
Vladimir Zhigulski ◽  
Daria Zhigulskaya ◽  
Vladimir Shuisky ◽  
Ekaterina Chebynina ◽  
Vitaly Panichev
Keyword(s):  
Sound Pressure ◽  
Animal Species ◽  
Riparian Ecosystems ◽  
Frequency Range ◽  
Noise Levels ◽  
Natural Ecosystems ◽  
Physiological Processes ◽  
Sound Pressure Levels ◽  
Noise Assessment ◽  
Natural Test

A comparative analysis of various biological objects sensitivity to acoustic effects is being conducted. For many animal species, the frequency range at which sounds are heard is very different from that for humans and may not even intersect with it. The total frequency range at which various animals can hear covers at least eight orders of magnitude (from hundredths of Hz to hundreds of kHz), while for humans this interval is limited to only four orders of magnitude. Thus, the existing anthropocentric standards for permissible noise levels are unsuitable for regulating their impacts on natural ecosystems and it is necessary to develop standards for sound pressure levels in the entire specified frequency range that are acceptable for the most sensitive recipients. For terrestrial and riparian ecosystems and protected areas, natural test subjects are birds, for which noise levels of 35-40 dBA do not cause pathological changes in behavior and physiological processes. This level can tentatively be considered as maximum permissible for man-made noise and for the noise of ports in particular. More reliable results will be given by regulating the permissible sound pressure levels in the entire frequency range based on reactions of the most sensitive recipients in each octave.

scholarly journals Measurement and Analysis of Infrasound Signals Generated by Operation of High-Power Wind Turbines

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6544
Author(s):  
Tomasz Malec ◽  
Tomasz Boczar ◽  
Daria Wotzka ◽  
Michał Kozioł
Keyword(s):  
Wind Turbines ◽  
High Power ◽  
Sound Pressure ◽  
Operating Time ◽  
Weather Conditions ◽  
Acoustic Energy ◽  
Working Environment ◽  
Frequency Range ◽  
Noise Levels ◽  
Measurement And Analysis

The development of wind energy and the increasing number of installed wind turbines make it necessary to assess them in terms of the nuisance of the emitted infrasound noise generated by such devices. The article presents the results of measurements and analyses of infrasound emitted during the operation of wind turbines installed in various locations in Poland. Comparative analysis of noise levels in the infrasound and audible range has shown that acoustic energy is mainly in the low and infrasound frequency range, and the measured levels depend significantly on the weighting curves used. On the basis of the results, it was confirmed that the sound pressure level of infrasound signals emitted by the operation of high-power wind turbines, regardless of wind velocity, weather conditions, design solutions of turbines, operating time, rated capacity, does not exceed the criteria specified in the applicable legislation dealing with the assessment of infrasound noise on the working environment.

EXPERIMENTAL STUDIES ON THE NOISE AND VIBRATION OF A SPECIAL BORING MACHINE DUE TO FORMATION OF THE OPERATOR´S WORKPLACE SOUND FIELD

Akustika ◽  
2019 ◽  
Vol 34 ◽  
pp. 100-103
Author(s):  
Alexander Shashurin ◽  
Marat Goguadze ◽  
Anna Lubianchenko
Keyword(s):  
Theoretical Analysis ◽  
Sound Pressure ◽  
Experimental Studies ◽  
Sound Radiation ◽  
Sound Field ◽  
Noise Levels ◽  
Noise And Vibration ◽  
Measurement Results ◽  
Sound Pressure Levels ◽  
Excessive Noise

The purpose of this study is to measure the octave sound pressure levels and vibrations of a boring machine. A theoretical analysis of the sound pressure levels near the boring machine is performed. The measurement results are given. It was found that the workplace sound pressure levels exceed the sanitary standards, which suggests that the excessive noise levels are due to the exposure to the cutter sound radiation and the axis being machined.

DEVELOPMENT OF THE METHODOLOGY FOR MEASURING NOISE LEVELS IN THE UNDERGROUND ROLLING STOCK

Akustika ◽  
2021 ◽  
pp. 183
Author(s):  
Aleksandr Shashurin ◽  
Konstantiv Fiev ◽  
Viktoriia Vasilyeva ◽  
Andrey Voronkov
Keyword(s):  
Sound Pressure ◽  
Rolling Stock ◽  
Noise Levels ◽  
Noise And Vibration ◽  
Frequency Bands ◽  
Sound Levels ◽  
Digital Spectrum ◽  
Sound Pressure Levels ◽  
Noise Measurements ◽  
Underground Railway

This document specifies the methodology for measuring equivalent sound pressure levels in octave frequency bands (in dB rel. 20 μPa), equivalent and maximum A-corrected sound levels (in dB rel. to 20 μPa), generated in the rolling stock in the driver’s cabins and in the passenger rooms of the salons, using acoustic meters - multifunctional analyzers Ecophysics, noise and vibration meters, spectrum analyzers Ecophysics 110A, Oktava 110A Eco, Oktava 110A, Oktava 111, B&K 2250, 2250L, 2270, noise and vibration analyzers ASSISTANT, noise and vibration meters, digital spectrum analyzers Algorithm-05, SVAN979. This methodology is applicable for noise measurements in the driver’s cabins and in the passenger rooms of the rolling stock of both new and old models operated by the underground railway.

Real Ear to 6-cm 3 Coupler Differences in Young Children

1993 ◽  
Vol 36 (1) ◽  
pp. 204-209 ◽  
Author(s):  
Dawna E. Lewis ◽  
Patricia G. Stelmachowicz
Keyword(s):  
Young Children ◽  
Pure Tone ◽  
Sound Pressure ◽  
Intersubject Variability ◽  
Frequency Range ◽  
Individual Basis ◽  
Sound Pressure Levels ◽  
Adults And Children ◽  
Speech Spectrum

Real-ear sound pressure levels under supra-aural earphones were measured for a group of young children (9 months to 7 years) and adults. Pure-tone signals were presented at nine test frequencies from 250 to 6000 Hz, and real ear to 6-cm 3 coupler differences were computed for each frequency. Results suggest that, by 2 years of age, average real ear to 6-cm 3 coupler differences are similar for adults and children. The intersubject variability for all groups supports the need for real-ear threshold measures on an individual basis in cases where the ability to amplify the speech spectrum to a level that is audible across the frequency range is in question.

scholarly journals Prediction of Turbulent Boundary Layer Induced Noise in the Cabin of a BWB Aircraft

2012 ◽  
Vol 19 (4) ◽  
pp. 693-705 ◽  
Author(s):  
Joana Rocha ◽  
Afzal Suleman ◽  
Fernando Lau
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Sound Pressure ◽  
Pressure Level ◽  
Interior Noise ◽  
Analytical Models ◽  
Frequency Range ◽  
Noise Levels ◽  
Cabin Noise ◽  
Cabin Interior

This paper discusses the development of analytical models for the prediction of aircraft cabin noise induced by the external turbulent boundary layer (TBL). While, in previous works, the contribution of an individual panel to the cabin interior noise was considered, here, the simultaneous contribution of multiple flow-excited panels is analyzed. Analytical predictions are presented for the interior sound pressure level (SPL) at different locations inside the cabin of a Blended Wing Body (BWB) aircraft, for the frequency range 0–1000 Hz. The results show that the number of vibrating panels significantly affects the interior noise levels. It is shown that the average SPL, over the cabin volume, increases with the number of vibrating panels. Additionally, the model is able to predict local SPL values, at specific locations in the cabin, which are also affected with by number of vibrating panels, and are different from the average values.

scholarly journals Modelling of underwater noise emissions by ships in Klaipėda Strait, Lithuania

Baltica ◽  
2021 ◽  
pp. 148-156
Author(s):  
Donatas Bagočius ◽  
Olga Anne ◽  
Aleksas Narščius
Keyword(s):  
Baltic Sea ◽  
Sound Pressure ◽  
Curonian Lagoon ◽  
Underwater Noise ◽  
Noise Levels ◽  
The Baltic Sea ◽  
Area Of Interest ◽  
Sound Pressure Levels ◽  
The Baltic ◽  
Harbour Area

One of the United Nations Sustainable Development Goals regarding “conservation and sustainable use of the oceans, seas, and marine resources” emphasizes the urgency of eliminating harmful effects on the sea and its biota, where the role of anthropogenic activities is crucial. The global trend of merchant shipping is increasing, thus enlarging underwater noise levels. As a result, greater noise can harm aquatic animals in their habitats. In the Baltic Sea, the underwater sound pressure levels are now being evaluated utilizing noise measurement, modelling, and mapping. In areas such as narrow ship passages, namely lagoons, channels, or straits, the ambient underwater noise modelling becomes very complex, even though these EU inland waters are regarded by legislation as part of the marine basin. For instance, the Klaipėda Channel (Klaipėda Strait), connecting the Baltic Sea and the Curonian Lagoon, is regarded by the national Lithuanian legislation as part of marine waters, where the environmental status should be evaluated according to the EU Maritime Strategy Framework Directive. In this narrow channel, an alternative to the modelling of ambient sound pressure levels can be applied to understand the long-term trends of vessel-sourced noise emissions. In this paper, an example of application of ship noise emission modelling for a narrow Klaipėda Harbour area is presented, along with the results obtained throughout 2015–2017. The modelled noise levels in the harbour area reached the median levels of 112.5 dB in 2015 and 102.6 dB re 1 µPa2 in 2017. The maximum emitted instantaneous sound pressure levels by ships reached 173.7 dB in 2015 and 179.4 dB re 1 µPa2 in 2017 in the area of interest.

Acoustic characteristics of wall jets over a rough surface

2020 ◽  
Vol 68 (5) ◽  
pp. 316-327
Author(s):  
Rahul S. Arackal ◽  
T.J.S. Jothi
Keyword(s):  
Surface Roughness ◽  
Rough Surface ◽  
Smooth Surface ◽  
Sound Pressure ◽  
Acoustic Measurements ◽  
Frequency Range ◽  
Noise Levels ◽  
Wall Jets ◽  
Acoustic Characteristics ◽  
Plate Length

The effects of surface roughness on the noise emissions from wall jets with a plate length (L) of 40 cm are presented in this article. The surface roughness of the plate considered for the study is in the range of 5 to 19 mm, and the jet velocity at the nozzle exit is varied from 20 to 56 m/s. Acoustic measurements of the different roughness plate wall jets are carried out at a distance of 60 cm from the jet axis and compared with that of a smooth surface. The spectral results indicate that the noise emissions from rough surface wall jets are lower in the frequency range (0.3â–“3.0 kHz), and the corresponding sound pressure levels are lower by around 5 dB compared to the noise from a smooth surface. Concurrently, the surface roughness is significant in generating higher noise levels by around 5 dB in the frequency range of 3 to 12 kHz compared to its counterpart.

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