scholarly journals The Correlation Between the Statistical Pass-By Index Values and the Total Number of Vehicle Passes

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Martin Decký ◽  
Eva Remišová ◽  
Matej Brna ◽  
Marek Drličiak ◽  
Matúš Kováč
Keyword(s):  
Asphalt Concrete ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Concrete Surface ◽  
Sound Level ◽  
Asphalt Pavements ◽  
Degradation Model ◽  
Mastic Asphalt ◽  
Sound Levels ◽  
Vehicle Velocity

Abstract In this study, the traffic noise degradation in asphalt pavements was analysed using the ‘Statistical Pass-By method’. The sound levels of two surfaces were monitored during 9 and 12 years of service, respectively. By comparing the dependencies of the maximum A-weighted sound pressure level on logarithm of vehicle velocity, an increase in the sound level was found at all recorded speeds. Following an analysis of sound levels, as combined with the statistical pass-by index (SPBI) calculated versus age (expressed in vehicles), it was determined that the noise is an increasing power function of SPBI values on vehicle passes, based on an approximation of noise level adjustment to a reference temperature of 20 °C (using a coefficient of 0.06 for asphalt concrete surface AC11 and - 0.03 for mastic asphalt SMA11). The adjusted traffic noise degradation model showed that the SMA11 surface has a higher resistance to acoustic degradation than AC11 surface.

scholarly journals Automotive traffic noise and urban public spaces

2021 ◽  
Vol 9 (72) ◽  
Author(s):  
Greicikelly Gaburro Paneto ◽  
Cristina Engel de Alvarez ◽  
Paulo Henrique Trombetta Zannin
Keyword(s):  
Urban Space ◽  
Sound Pressure ◽  
Traffic Noise ◽  
Motor Vehicles ◽  
Open Spaces ◽  
Sound Levels ◽  
Measurement Results ◽  
Sound Pressure Levels ◽  
High Sound

In contemporary cities, and usually without realizing it, the population has been exposed to high sound pressure levels, which besides causing discomfort, can lead to health problems. Considering that a large part of this noise comes from emission from motor vehicles, this research aims to evaluate the sound behavior in sound environments configured by voids in the urban fabric, in order to identify whether open spaces can act as attenuators of sound levels. To obtain the expected results, the methodology used was structured from a review of the state-of-the-art and computer simulations relating the variables that influence the formation of urban space and sound emission and propagation, taking as a case study an urban portion of the municipality of Vitória/ES. In parallel, questionnaires were applied to evaluate the user's perception of their exposure. The measurement results indicated that the sound pressure levels caused by traffic noise are above the limit tolerated limit by the NBR norm 10151:2000 for the daytime period. In turn, the results obtained from the population indicated that there is little perception of noise by the users of the spaces surveyed.

Statistical Study of the Instantaneous Values of Traffic Noise Sound Pressure Level

2002 ◽  
Vol 33 (8) ◽  
pp. 16-24
Author(s):  
Jesús Alba Fernández ◽  
Marcelino Ferri García ◽  
Jaime Ramis Soriano ◽  
Juan Antonio Martínez Mora
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Road Traffic ◽  
Traffic Noise ◽  
Relevant Information ◽  
Sound Level ◽  
Pressure Level ◽  
Road Traffic Noise ◽  
Statistical Parameters ◽  
Sound Event

In environmental acoustics the knowledge of the time dependency of the sound level provides relevant information about a sound event. In this sense, it may be said that conventional sound level metres have frequently implemented programs to calculate the fractiles (percentiles) of the distribution of instantaneous sound levels; and there are several indexes to evaluate the noise pollution, based on different statistical parameters. For further analysis of sound, and to obtain the commented indexes, it is accepted that this distribution is normal or gaussian. The questions we've tried to solve in this work are the following: First of all, whether the time dependent distribution of the variable sound pressure level should be considered as Gaussian in general cases or only in some particular ones. On the other hand, we have studied how the frequency of the sampling affects the resulting distribution of a given a sound event. To these ends, a set of road traffic noise events has been evaluated. Furthermore, even in gaussian distributions of sound pressure levels, the average of the distribution will not be coincident with the equivalent sound pressure level; that is the level of the average quadratic pressure. The difference between this parameter, and its dependence on the standard deviation, is studied.

Assessment of Environmental Noise and Air Quality in Critical Areas at UiTM Engineering Complex

2013 ◽  
Vol 471 ◽  
pp. 125-129
Author(s):  
N.V. David ◽  
K. Ismail
Keyword(s):  
Air Quality ◽  
Sound Pressure ◽  
Quality Measurement ◽  
Environmental Noise ◽  
Sound Level ◽  
Public Parks ◽  
Noise Sources ◽  
Critical Areas ◽  
Sound Levels ◽  
Sound Pressure Levels

Excessive environmental noise and poor air quality can be adverse to human health, living comfort and the environment itself. Measurement of sound pressure levels and air quality in critical areas including libraries, campus areas, public parks and hospitals thus becomes necessary to monitor and mitigate existing noise levels. In a university environment, student activities will be less disrupted if the locations of the activities are sufficiently away from noise sources. The present study is intended to measure sound levels and air quality around the Engineering Complex, Universiti Teknologi Mara, Shah Alam. The measured data is compared with to acceptable sound pressure levels and air quality index specified by the Department of Environment (DOE), Malaysia. Sound pressure levels are measured using the Castle Sound Level Meter Type 6224 and air quality measurement was done by using the BW Gas Alert MicroClip XT device. Both measurements were conducted at five selected stations around the Engineering Complex for three times each weekday for five weeks. Results obtained indicated that sound levels at some locations and time zones are above the thresholds recommended by the DOE. The air quality is acceptable in most locations except the vicinity of a bus stop. With the growing number of students in the university and other factors like construction and redevelopment of existing roads, a continuously increasing noise situations and air pollution proportional to the traffic flow is inevitable.

R-weighting provides better estimation for rat hearing sensitivity

2000 ◽  
Vol 34 (2) ◽  
pp. 136-144 ◽  
Author(s):  
E. Böjrk ◽  
T. Nevalainen ◽  
M. Hakumäki ◽  
H.-M. Voipio
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Sound Studies ◽  
Response Curves ◽  
Acoustic Environment ◽  
High Frequencies ◽  
Hearing Sensitivity ◽  
Sound Levels

Since sounds may induce physiological and behavioural changes in animals, it is necessary to assess and define the acoustic environment in laboratory animal facilities. Sound studies usually express sound levels as unweighted linear sound pressure levels. However, because a linear scale does not take account of hearing sensitivity-which may differ widely both between and within species at various frequencies-the results may be spurious. In this study a novel sound pressure level weighting for rats, R-weighting, was calculated according to a rat's hearing sensitivity. The sound level of a white noise signal was assessed using R-weighting, with H-weighting tailored for humans, A-weighting and linear sound pressure level combined with the response curves of two different loudspeakers. The sound signal resulted in different sound levels depending on the weighting and the type of loudspeaker. With a tweeter speaker reproducing sounds at high frequencies audible to a rat, R- and A-weightings gave similar results, but the H-weighted sound levels were lower. With a middle-range loudspeaker, unable to reproduce high frequencies, R-weighted sound showed the lowest sound levels. In conclusion, without a correct weighting system and proper equipment, the final sound level of an exposure stimulus can differ by several decibels from that intended. To achieve reliable and comparable results, standardization of sound experiments and assessment of the environment in animal facilities is a necessity. Hence, the use of appropriate species-specific sound pressure level weighting is essential. R-weighting for rats in sound studies is recommended.

scholarly journals RESEARCH ON EMERGING AND DESCENDING AIRCRAFT NOISE / KYLANČIŲ IR BESILEIDŽIANČIŲ ORLAIVIŲ KELIAMO TRIUKŠMO TYRIMAI

2013 ◽  
Vol 5 (4) ◽  
pp. 337-342
Author(s):  
Monika Bartkevičiūtė ◽  
Raimondas Grubliauskas
Keyword(s):  
Negative Impact ◽  
Traffic Noise ◽  
Aircraft Engine ◽  
Sound Level ◽  
Aircraft Noise ◽  
Large Radius ◽  
Sound Levels ◽  
Conducting Research ◽  
High Level ◽  
The Impact

Along with an increase in the aircraft engine power and growth in air traffic, noise level at airports and their surrounding environs significantly increases. Aircraft noise is high level noise spreading within large radius and intensively irritating the human body. Air transport is one of the main sources of noise having a particularly strong negative impact on the environment. The article deals with activities and noises taking place in the largest nationwide Vilnius International Airport.The level of noise and its dispersion was evaluated conducting research on the noise generated by emerging and descending aircrafts in National Vilnius Airport. Investigation was carried out at 2 measuring points located in a residential area. There are different types of aircrafts causing different sound levels. It has been estimated the largest exceedances that occur when an aircraft is approaching. In this case, the noisiest types of aircrafts are B733, B738 and AT72. The sound level varies from 70 to 85 dBA. The quietest aircrafts are RJ1H and F70. When taking off, the equivalent of the maximum sound level value of these aircrafts does not exceed the authorized limits. The paper describes the causes of noise in aircrafts, the sources of origin and the impact of noise on humans and the environment. Article in Lithuanian. Santrauka Padidėjus orlaivių variklių galiai ir daugėjant skrydžių, labai padidėjo oro uostuose ir šalia jų esančiose apylinkėse skleidžiamo triukšmo lygis. Lėktuvo keliamas triukšmas išsiskiria aukštu garso slėgio lygiu bei dideliu spinduliu sklindančiu garsu ir yra labiausiai dirginantis žmogaus organizmą. Orlaivių transportas – vienas pagrindinių triukšmo šaltinių, darantis ypač didelę neigiamą įtaką aplinkai. Nagrinėjamas Tarptautiniame Vilniaus oro uoste kylančių ir tupiančių orlaivių keliamas triukšmas. Triukšmo tyrimai atlikti gyvenamojoje aplinkoje greta oro uosto parinktose matavimo vietose. Pateikiami įvairių orlaivių tipų sukeliamo garso stiprumo – garso slėgio lygiai. Didžiausias leistinųjų verčių viršijimas nustatomas orlaiviams leidžiantis. Triukšmingiausi B733, B738 ir AT72 tipo orlaiviai – garso slėgio lygis 70–85 dBA. Vieni tyliausių orlaivių – RJ1H ir F70. Jiems kylant ekvivalentinės ir maksimalios garso slėgio lygio reikšmės neviršija leidžiamųjų. Aprašomos orlaivių keliamo triukšmo priežastys, kilimo šaltiniai. Nagrinėjamas triukšmo poveikis žmogui ir aplinkai.

Tutorial and Guidelines on Measurement of Sound Pressure Level in Voice and Speech

2018 ◽  
Vol 61 (3) ◽  
pp. 441-461 ◽  
Author(s):  
Jan G. Švec ◽  
Svante Granqvist
Keyword(s):  
Sound Pressure Level ◽  
Background Noise ◽  
Sound Pressure ◽  
Signal To Noise Ratio ◽  
Practical Experience ◽  
Sound Level ◽  
Pressure Level ◽  
Sound Levels ◽  
Frequency Weighting ◽  
Voice And Speech

Purpose Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility. Method Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers. Results Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones. Conclusions SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech.

Mesa Verde National Park: Acoustic monitoring report

2021 ◽  
Author(s):  
Jacob Job
Keyword(s):  
Sound Pressure Level ◽  
National Park ◽  
Sound Pressure ◽  
Sound Level ◽  
Pressure Level ◽  
Logarithmic Scale ◽  
Noise Sources ◽  
Mesa Verde ◽  
Sound Levels ◽  
Human Ear

In 2015, the Natural Sounds and Night Skies Division (NSNSD) received a request to collect baseline acoustical data at Mesa Verde National Park (MEVE). Between July and August 2015, as well as February and March 2016, three acoustical monitoring systems were deployed throughout the park, however one site (MEVE002) stopped recording after a couple days during the summer due to wildlife interference. The goal of the study was to establish a baseline soundscape inventory of backcountry and frontcountry sites within the park. This inventory will be used to establish indicators and thresholds of soundscape quality that will support the park and NSNSD in developing a comprehensive approach to protecting the acoustic environment through soundscape management planning. Additionally, results of this study will help the park identify major sources of noise within the park, as well as provide a baseline understanding of the acoustical environment as a whole for use in potential future comparative studies. In this deployment, sound pressure level (SPL) was measured continuously every second by a calibrated sound level meter. Other equipment included an anemometer to collect wind speed and a digital audio recorder collecting continuous recordings to document sound sources. In this document, “sound pressure level” refers to broadband (12.5 Hz–20 kHz), A-weighted, 1-second time averaged sound level (LAeq, 1s), and hereafter referred to as “sound level.” Sound levels are measured on a logarithmic scale relative to the reference sound pressure for atmospheric sources, 20 μPa. The logarithmic scale is a useful way to express the wide range of sound pressures perceived by the human ear. Sound levels are reported in decibels (dB). A-weighting is applied to sound levels in order to account for the response of the human ear (Harris, 1998). To approximate human hearing sensitivity, A-weighting discounts sounds below 1 kHz and above 6 kHz. Trained technicians calculated time audible metrics after monitoring was complete. See Methods section for protocol details, equipment specifications, and metric calculations. Median existing (LA50) and natural ambient (LAnat) metrics are also reported for daytime (7:00–19:00) and nighttime (19:00–7:00). Prominent noise sources at the two backcountry sites (MEVE001 and MEVE002) included vehicles and aircraft, while building and vehicle predominated at the frontcountry site (MEVE003). Table 1 displays time audible values for each of these noise sources during the monitoring period, as well as ambient sound levels. In determining the current conditions of an acoustical environment, it is informative to examine how often sound levels exceed certain values. Table 2 reports the percent of time that measured levels at the three monitoring locations were above four key values.

scholarly journals Noise levels of a track-laying tractor during field operations in the vineyard

2013 ◽  
Vol 44 (2s) ◽  
Author(s):  
Pietro Catania ◽  
Mariangela Vallone
Keyword(s):  
Sound Pressure ◽  
Health And Safety ◽  
Sound Level ◽  
Noise Levels ◽  
Test Conditions ◽  
Maximum Value ◽  
Sound Levels ◽  
Class 1 ◽  
Level Meter ◽  
Almost All

Noise in agriculture is one of the risk factors to be taken into account in the assessment of the health and safety of workers; in particular, it is known that the tractor is a source of high noise. The Italian Low 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 paper concerns the analysis of the noise risk arising from the use of a tracklaying tractor during field operations carried out in the vineyard. The objective of this study was to evaluate the noise level that comes close to the ear of the operator driving the tractor measuring the values of equivalent sound level (Leq(A)) and peak sound pressure (LCpk). We considered four options related to the same tractor coupled with the following tools to perform some farming operations: rototilling, chisel plough, flail mowers and vibro farmer. We considered three test conditions: T1 in flat (slope 0%), T2 uphill and T3 downhill (both 30% slope). The instrument used for the measurements is a precision integrating portable sound level meter, class 1, model HD2110L by Delta OHM, Italy. Each survey lasted 2 minutes, with an interval of measurement equal to 0.5 s. The tests were performed in compliance with the standards ISO 9612 and ISO 9432. The results show that the measured sound levels exceed the limits allowed by the regulations in almost all the test conditions; values exceeding the threshold limit of 80 dB(A) were recorded coming up to a maximum value of 92.8 dB(A) for flail mowers in test T1. When limits imposed by the regulations are exceeded, the operator is obliged to wear the appropriate Personal Protective Equipment.

Florida Noise Barrier Evaluation and Computer Model Validation

2003 ◽  
Vol 1859 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Roger Wayson ◽  
John MacDonald ◽  
Ahmed EI-Assar ◽  
Win Lindeman ◽  
Mariano Berrios
Keyword(s):  
Insertion Loss ◽  
Traffic Noise ◽  
Sound Level ◽  
Noise Model ◽  
Barrier Method ◽  
Noise Barriers ◽  
Zone Length ◽  
Sound Levels ◽  
Noise Barrier ◽  
Source Level

The results of a project that investigated the effectiveness of in situ noise barriers in Florida are presented. The prediction accuracy of the FHWA Traffic Noise Model (TNM) is compared with STAMINA 2.0 and 2.1 (Florida-specific). A total of 20 barrier sites were visited during a 3-year period that resulted in 844 discrete 20-min equivalent sound level (Leq) measurements behind the barriers. Barrier insertion loss was determined using the ANSI indirect barrier method. A methodology was developed to estimate shadow zone length created behind highway noise barriers. All of the barriers tested were effective (>5 dB:LAeq insertion loss at distances equivalent to the first row of homes, where LAeq is the A-weighted Leq) except one site because of marginal additional shielding from a berm–barrier combination. Only three sites had an insertion loss of less than 5 dB at distances representative of the second row of homes. Overall, measurements indicate that the barriers provide substantial sound level reduction for residents along the highway. TNM was the best prediction model when considering all test sites; however, the STAMINA models were more accurate at predicting source level. TNM predictions using the Average pavement input overpredicted the reference sound levels measured at these sites. TNM predictions using the OGAC (open-graded asphalt concrete) input were improved (under 2 dB:LAeq of error) over those using the Average pavement type input. This result is expected because Florida uses an open-graded asphalt friction mix.

Low-Noise Asphalt Pavements in Urban Areas

2016 ◽  
Vol 858 ◽  
pp. 282-286
Author(s):  
Petr Kozak ◽  
Ondrej Dasek ◽  
Radka Matuszkova ◽  
Michal Radimsky
Keyword(s):  
Asphalt Concrete ◽  
Urban Areas ◽  
Road Traffic ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Low Noise ◽  
Thin Layers ◽  
Asphalt Pavements ◽  
Road Traffic Noise ◽  
Vehicle Speed

Current requirements for the reduction of the noise pollution in inhabited areas are constantly increasing. Acoustic wearing courses represent the real measures how to directly mitigate sources of road traffic noise created by a tire/road contact. Directly reduced noise emissions created by a tire/road contact don't need further mitigation by expensive noise barriers. Noise emissions on two different types of wearing courses of asphalt mixtures (Asphalt concrete for very thin layers and Low-noise stone mastic asphalt) were measured using the specialized device operating on the basis of CPX (Close Proximity method) and compared with the standard mixture of Asphalt concrete. Differences were between 1 dB and 5 dB depending on the wearing course and the vehicle speed. The efficiency of the low-noise asphalt pavements was also compared with the initial costs of the pavements. The economical evaluation confirmed that the initial costs of the acoustic wearing courses are higher than the costs of the standard asphalt concrete mixture. However the noise reduction by 1 dB using the asphalt concrete for very thin layers increases the costs just by 350 USD (considering the same length and width of the road segment), which makes acoustic wearing courses the economically efficient noise reducing measure.

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