The improved automatic control points computation for the acoustic noise
                        level audits

<p class="Abstract">The acoustic noise level in the interior is one of the quantities specified by a standard and is subject to audits to ensure a comfortable living environment. Currently, the noise level audits are performed manually by a skilled operator, who evaluates the floor plan and uses it to calculate the control points location in which the measurement is performed. The computation is proposed to automate the audit by formulating an optimisation problem for which an algorithm was designed. The algorithm computes the solution that satisfies all constraints specified in the standard, for example, the minimum distance among the control points and fixed obstacles (walls or columns). In the proposed optimisation problem, the fitness function was designed based on the measurement purpose, and two typical use-cases were analysed: (i) long-term stationary noise measurement and (ii) recurring short-term noise measurement. Although the set of control points for both use cases complies with the given standard, it is beneficial to distinguish the location of control points based on the measurement purpose. The number of control points is maximised for the stationary noise and for the immediate coverage area for the short-term noise. The proposed algorithms were tested in a simulation for several floor plans of different complexity.</p>

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Characterization of Noise Level Inside a Vehicle under Different Conditions

Sensors ◽

10.3390/s20092471 ◽

2020 ◽

Vol 20 (9) ◽

pp. 2471 ◽

Cited By ~ 3

Author(s):

Daniel Flor ◽

Danilo Pena ◽

Luan Pena ◽

Vicente A. de Sousa ◽

Allan Martins

Keyword(s):

Regression Analysis ◽

Noise Level ◽

Acoustic Noise ◽

Experimental Setup ◽

Strongly Correlated ◽

Noise Levels ◽

Noise Sources ◽

Statistical Tools ◽

Window Position

Vehicular acoustic noise evaluations are a concern of researchers due to health and comfort effects on humans and are fundamental for anyone interested in mitigating audio noise. This paper focuses on the evaluation of the noise level inside a vehicle by using statistical tools. First, an experimental setup was developed with microphones and a microcomputer located strategically on the car’s panel, and measurements were carried out with different conditions such as car window position, rain, traffic, and car speed. Regression analysis was performed to evaluate the similarity of the noise level from those conditions. Thus, we were able to discuss the relevance of the variables that contribute to the noise level inside a car. Finally, our results revealed that the car speed is strongly correlated to interior noise levels, suggesting the most relevant noise sources are in the vehicle itself.

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MODELING OF THE SPREAD OF MOTOR TRANSPORT NOISE IN ŠIAULIAI CITY / AUTOTRANSPORTO TRIUKŠMO SKLAIDOS ŠIAULIUOSE MODELIAVIMAS / МОДЕЛИРОВАНИЕ РАССЕЯНИЯ ТРАНСПОРТНОГО ШУМА В ГОРОДЕ ШЯУЛЯЙ

Journal of Environmental Engineering and Landscape Management ◽

10.3846/16486897.2011.557249 ◽

2011 ◽

Vol 19 (1) ◽

pp. 62-70 ◽

Cited By ~ 8

Author(s):

Leonas Paulauskas ◽

Robertas Klimas

Keyword(s):

Personal Computer ◽

Noise Level ◽

Negative Impact ◽

Noise Measurement ◽

Motor Transport ◽

City Environment ◽

Measurement Results ◽

The Difference ◽

Environment Noise ◽

Level Detector

Rapidly growing urbanization causes the increase of noise level of various sources, that have a negative impact upon people's health. The contribution of noise caused by motor transport in city environment composes up to 80% of general impact of all the sources. The article presents the results of modeling of the spread of motor transport noise of Šiauliai city, maps of motor transport noise, recommendations for management of environment noise. MapNoise programme module, adapted to work in the ArcGIS Desktop 9.1 environment, was used for modeling motor transport noise. Noise measurement researches have been carried out using digital noise isolator Nor121, completed with digital level detector. NorXfar software was used to send the data to personal computer. Having evaluated the validity of modeling results it has been determined that the difference between the night noise modeling and measurement results does not exceed 2.2%, and varies from 0.5dB(A) to 1.1 dB(A). The obtained results indicate that 7.2% of the apartments of all city residents are influenced by the LDEN noise that exceeds the permitted noise level (LDEN >65 dB(A)) and 31.2% of the apartments of the residents are influenced by night noise that exceeds the permitted noise level (LN > 55 dB(A)). Santrauka Sparčiai vykstant urbanizacijos procesui, kinta įvairių šaltinių keliamo triukšmo lygis, didėja neigiama įtaka žmonių sveikatai. Miestų aplinkoje iki 80 % visuminio visų triukšmo šaltinių poveikio tenka autotransporto keliamam triukšmui.Straipsnyje pateikta autotransporto triukšmo sklaidos Šiauliuose modeliavimo rezultatai, autotransporto triukšmo žemėlapiai, aplinkos triukšmo valdymo rekomendacijos. Autotransporto triukšmui modeliuoti naudotas MapNoise programinismodulis, pritaikytas darbui ArcGIS Desktop 9.1 aplinkoje. Iš rezultatų matyti, kad 7,2% visų miesto gyventojų būstų yra veikiami paros triukšmo, viršijančio leidžiamąjį triukšmo lygį (LDVN > 65 dB(A)), ir 31,2% gyventojų būstų veikiami nakties triukšmo, viršijančio leidžiamąjį triukšmo lygį (LN > 55 dB(A)). Įvertinus modeliavimo rezultatų patikimumą nustatyta, kad paros ir nakties triukšmo modeliavimo ir matavimo rezultatų neatitiktis neviršija 2,2 % ir svyruoja nuo 0,5dB(A) iki 1,1dB(A). Резюме При быстром росте урбанизации увеличивается уровень шума, создаваемого разными источниками и отрицательно влияющего на здоровье населения. Шум от автотранспорта в городах составляет около 80% от всех источников шума. В статье представлены результаты моделирования рассеяния шума от автотранспорта в городеШяуляй, карты автотранспортного шума, рекомендации по управлению шумом в окружающей среде. Приизмерении шума был использован числовой анализатор шума № 121, укомплектованный с числовым детекторомуровня RMS. Для передачи данных в персональный компьютер использована программа NorXfer. Для моделирования автотранспортного шума использован программный модуль MapNoise, приспособленный дляработы в среде ArcGIS desktop 9.1. При анализе достоверности результатов моделирования было установлено, чтоих отличие от результатов измерения шума в течение суток и ночное время не превышает 2,2% и колеблется от0,5дБ(A) до 1,1дБ(A). Результаты исследования свидетельствуют о том, что 7,2% жилых помещений городаподвергаются суточному шуму, уровень которого превышает допустимый (LDVN > 65 дБ(A)) и 31,2% жилыхпомещенийгородаподвергаютсяшумувночноевремя,уровень которогопревышаетдопустимый (LN > 55дБ(A)).

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Octave Band Technique for Noise Measurement at the Source, Path, and Receiver of Gas Turbines in Oil and Gas Facilities

Pertanika Journal of Science and Technology ◽

10.47836/pjst.30.1.39 ◽

2022 ◽

Vol 30 (1) ◽

pp. 725-745

Author(s):

Akmal Haziq Mohd Yunos ◽

Nor Azali Azmir

Keyword(s):

Gas Turbine ◽

Noise Level ◽

Gas Turbines ◽

Noise Exposure ◽

Oil And Gas ◽

Noise Pollution ◽

Noise Measurement ◽

Octave Band ◽

High Noise ◽

Safety And Health

Noise measurement is essential for industrial usage. However, further attention to preventing noise pollution is needed, especially when working with equipment generating a high noise level, such as gas turbines. This study aims to determine the best way to perform noise measurement and analyze the octave band frequency generated by noise pollution caused by gas turbine equipment. Data from site measurements show that the gas turbines produce more than 85 dB of noise with a Z-weighted measurement. A noise measuring investigation was conducted to obtain the data for the 1/3 octave band. A frequency-domain was used to comprehend the properties of the noise measurement frequency band. The frequency band was classified into three different zones called low, medium, and high frequency, which is useful in noise measurement analysis to identify a viable solution to reduce the noise. On-site sampling was performed at the source, path, and receiver of three separate gas turbine locations within oil and gas operations. The 1/3 octave band data collection results at the sound source, path, and receiver demonstrate the noise level distribution at the perimeter of gas turbine installations in the low and medium frequency ranges. Most of the high noise frequency range is between 250 Hz and 2 kHz for source, path, and receiver. All acquired values are compared to the Department of Safety and Health (Occupational Safety and Health (Noise Exposure) Regulations 2019 in Malaysia. As a result, oil and gas service operators can monitor and take countermeasures to limit noise exposure at oil and gas facilities.

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Pipe crack early warning for burst prevention by permanent acoustic noise level monitoring in smart water networks

Urban Water Journal ◽

10.1080/1573062x.2020.1828501 ◽

2020 ◽

Vol 17 (9) ◽

pp. 827-837

Author(s):

Chi Zhang ◽

Martin F. Lambert ◽

Mark L. Stephens ◽

Jinzhe Gong ◽

Benjamin S. Cazzolato

Keyword(s):

Early Warning ◽

Noise Level ◽

Acoustic Noise ◽

Water Networks ◽

Smart Water ◽

Level Monitoring

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Development of Technologies for Eliminating High-Level Noise Emitting Vehicles on Japanese Roads

Volume 17: Transportation Systems ◽

10.1115/imece2008-66732 ◽

2008 ◽

Author(s):

Masao Ishihama ◽

Shigehiko Kaneko ◽

Minoru Kamata ◽

Takeharu Tanaka ◽

Ichiro Sakamoto

Keyword(s):

Measurement Technique ◽

Noise Level ◽

Subjective Evaluation ◽

Noise Measurement ◽

Original Position ◽

Operation Condition ◽

Engine Operation ◽

Vehicle Acceleration ◽

Exhaust Noise ◽

High Level

The purpose of the present study is to improve the on-street exhaust noise measurement technique for regulating vehicles that emit unacceptably large exhaust noise. The method under development uses racing operation of engines with a wide-open throttle on a standing vehicle. In contrast, the engine operation condition considered in the conventional on-street measurement technique considers operation at 75% of rated power followed by the throttle valve being released to its original position. The current regulation considers the maximum noise level during this engine operation condition. Accordingly, the engine is not loaded during testing. This loading condition provides unsatisfactory correlation between the exhaust noise level measured by the on-street method and the ISO vehicle acceleration noise under the wide-open throttle condition. The present paper reports the advantages of the proposed method as well as some important factors in the proper application of the newly proposed method. In the present study, we perform noise measurement along highways, a vehicle experiment in an anechoic chassis dynamometer, and computer simulations. The results revealed that the proposed on-street measurement method can be used to approximately determine the exhaust noise level during full acceleration for most vehicle types. In addition, the sensitivities of the measured noise levels for the testing conditions were clarified. The second item in this study is efficient engine speed measurement using exhaust sound signal only without electric wire harnessing. A survey of the measurement systems proposed by three different companies revealed that the measurement principles of two of these systems have potential application to on-street exhaust measurement. The last item investigated herein is better indices of exhaust noise evaluation. Loudness defined by ISO was found to be much better than the conventional dB(A) scale in terms of correlation with subjective evaluation results.

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A Digital Signal Processor Based Acoustic Sensor for Outdoor Noise Monitoring in Smart Cities

Sensors ◽

10.3390/s20030605 ◽

2020 ◽

Vol 20 (3) ◽

pp. 605 ◽

Cited By ~ 4

Author(s):

Juan Manuel López ◽

Jesús Alonso ◽

César Asensio ◽

Ignacio Pavón ◽

Luis Gascó ◽

...

Keyword(s):

Acoustic Noise ◽

Smart Cities ◽

Monitoring Network ◽

Noise Pollution ◽

Sound Level ◽

Noise Measurement ◽

Acoustic Sensor ◽

Measurement Instruments ◽

Frequency Weighting

Presently, large cities have significant problems with noise pollution due to human activity. Transportation, economic activities, and leisure activities have an important impact on noise pollution. Acoustic noise monitoring must be done with equipment of high quality. Thus, long-term noise monitoring is a high-cost activity for administrations. For this reason, new alternative technological solutions are being used to reduce the costs of measurement instruments. This article presents a design for a versatile electronic device to measure outdoor noise. This device has been designed according to the technical standards for this type of instrument, which impose strict requirements on both the design and the quality of the device’s measurements. This instrument has been designed under the original equipment manufacturer (OEM) concept, so the microphone–electronics set can be used as a sensor that can be connected to any microprocessor-based device, and therefore can be easily attached to a monitoring network. To validate the instrument’s design, the device has been tested following the regulations of the calibration laboratories for sound level meters (SLM). These tests allowed us to evaluate the behavior of the electronics and the microphone, obtaining different results for these two elements. The results show that the electronics and algorithms implemented fully fit within the requirements of type 1 noise measurement instruments. However, the use of an electret microphone reduces the technical features of the designed instrument, which can only fully fit the requirements of type 2 noise measurement instruments. This situation shows that the microphone is a key element in this kind of instrument and an important element in the overall price. To test the instrument’s quality and show how it can be used for monitoring noise in smart wireless acoustic sensor networks, the designed equipment was connected to a commercial microprocessor board and inserted into the infrastructure of an existing outdoor monitoring network. This allowed us to deploy a low-cost sub-network in the city of Málaga (Spain) to analyze the noise of conflict areas due to high levels of leisure noise. The results obtained with this equipment are also shown. It has been verified that this equipment meets the similar requirements to those obtained for type 2 instruments for measuring outdoor noise. The designed equipment is a two-channel instrument, that simultaneously measures, in real time, 86 sound noise parameters for each channel, such as the equivalent continuous sound level (Leq) (with Z, C, and A frequency weighting), the peak level (with Z, C, and A frequency weighting), the maximum and minimum levels (with Z, C, and A frequency weighting), and the impulse, fast, and slow time weighting; seven percentiles (1%, 5%, 10%, 50%, 90%, 95%, and 99%); as well as continuous equivalent sound pressure levels in the one-third octave and octave frequency bands.

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Estimation of the mean power content of summed sinusoids and an application to acoustic noise measurement in shallow water

Journal of Sound and Vibration ◽

10.1016/0022-460x(80)90491-5 ◽

1980 ◽

Vol 73 (1) ◽

pp. 41-59

Author(s):

A.W. Walker

Keyword(s):

Shallow Water ◽

Acoustic Noise ◽

Noise Measurement ◽

Mean Power ◽

Power Content ◽

The Mean ◽

Acoustic Noise Measurement

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Rapid recovery following short-term acoustic disturbance in two fish species

Royal Society Open Science ◽

10.1098/rsos.150686 ◽

2016 ◽

Vol 3 (1) ◽

pp. 150686 ◽

Cited By ~ 17

Author(s):

Rick Bruintjes ◽

Julia Purser ◽

Kirsty A. Everley ◽

Stephanie Mangan ◽

Stephen D. Simpson ◽

...

Keyword(s):

Fish Species ◽

Noise Exposure ◽

Acoustic Noise ◽

Experimental Studies ◽

Ventilation Rate ◽

Rapid Recovery ◽

Ambient Conditions ◽

Short Term ◽

Additional Noise ◽

Startle Latency

Noise from human activities is known to impact organisms in a variety of taxa, but most experimental studies on the behavioural effects of noise have focused on examining responses associated with the period of actual exposure. Unlike most pollutants, acoustic noise is generally short-lived, usually dissipating quickly after the source is turned off or leaves the area. In a series of experiments, we use established experimental paradigms to examine how fish behaviour and physiology are affected, both during short-term (2 min) exposure to playback of recordings of anthropogenic noise sources and in the immediate aftermath of noise exposure. We considered the anti-predator response and ventilation rate of juvenile European eels ( Anguilla anguilla ) and ventilation rate of juvenile European seabass ( Dicentrarchus labrax ). As previously found, additional-noise exposure decreased eel anti-predator responses, increased startle latency and increased ventilation rate relative to ambient-noise-exposed controls. Our results show for the first time that those effects quickly dissipated; eels showed rapid recovery of startle responses and startle latency, and rapid albeit incomplete recovery of ventilation rate in the 2 min after noise cessation. Seabass in both laboratory and open-water conditions showed an increased ventilation rate during playback of additional noise compared with ambient conditions. However, within 2 min of noise cessation, ventilation rate showed complete recovery to levels equivalent to ambient-exposed control individuals. Care should be taken in generalizing these rapid-recovery results, as individuals might have accrued other costs during noise exposure and other species might show different recovery times. Nonetheless, our results from two different fish species provide tentative cause for optimism with respect to recovery following short-duration noise exposure, and suggest that considering periods following noise exposures could be important for mitigation and management decisions.

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