ROAD CONSTRUCTION NOISE MEASUREMENT, PREDICTION AND CONTROL.

This study investigates the acoustic conditions of a design studio (Studio 130) in the Department of Interior Architecture and Environmental Design at Afyon Kocatepe University by integrating 14 weeks of continuous noise measurements with perception data collected from 192 students. Noise measurements were conducted in accordance with ISO 3382-3:2022 guidelines at three locations—window front, door side, and studio midpoint—during morning, noon, and evening periods, with 10 min recordings at each session. The results indicate that when students were present, the equivalent continuous noise level (Leq) reached an average of 65.5 dB(A), with peak levels rising to 72.3 dB(A) during jury sessions. These values substantially exceed the recommended 35 dB(A) classroom threshold by the World Health Organization and the 35–45 dB(A) limits specified in national regulations for indoor educational spaces. Survey findings reveal that 88% of students experienced loss of concentration, 72% reported decreased productivity, 60% had difficulty communicating, and 52% reported fatigue due to noise exposure. Pearson correlation analysis demonstrated a strong relationship between measured noise levels and reported negative effects (r = 0.966). Moreover, independent samples t-test results confirmed that student presence significantly increased studio noise levels (t = 4.98, p < 0.001). The novelty of this research lies in its combined use of longitudinal objective measurements and subjective perception data, addressing the unique open-plan, collaborative, and critique-based pedagogical structure of design studios. The findings highlight that acoustic comfort is a critical component of learning quality in studio-based education. Based on the results, the study proposes several design and material interventions—including spatial dividers, acoustic ceiling panels, fabric-wrapped absorbers, and impact-reducing flooring—to enhance auditory comfort. Overall, the study emphasizes the necessity of integrating acoustic design strategies into studio pedagogy to support concentration, communication, and learning performance.

Present work was carried out to collect primary data from the field with the help of noise meter and thus spatial anddiurnal variation of background and aircraft noise level was analyzed. Seventeen sampling sites were chosennearby Tribhuwan International Airport (TIA) and air route of aircraft flyover. Noise measurements were carried outunder normal atmospheric environmental condition at temperature ranges from 25°C-30°C excluding rainy andwindy days. Among the sampling sites, the Equivalent Continuous Noise Level (LAeq) of background noise measuredmaximum at Balkumari (73.2 dBA) and minimum at Datidol (49.2 dBA). Noise meter was allowed to record aircraftnoise level when aircraft produced noise greater than background noise level and recorded until it reduced tobackground noise level. The maximum value of aircraft noise level, (LAeq) measured at Gothatar (101.5 dBA) whichlies north east from the TIA and at the same height as the airport ground and minimum at Datidol (63.5 dBA).Toanalyse the spatial variation of aircraft noise of different sampling sites, contour map was plotted with the help oforigin software. The LAeq of more than 60 percent sampling sites fall under the severe noise exposure class (> 75dBA) which causes substantial hearing loss. Implementation of noise control measurement and public awarenessare recommended to control adverse effect of noise pollution.DOI: http://dx.doi.org/10.3126/njst.v15i1.12031Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 139-144

Environmental noise is a significant public health issue, particularly in rapidly urbanizing cities where commercial activities contribute to elevated noise pollution. Despite its numerous implications, few studies have focused on noise levels in commercial environments in developing countries. This study aims to fill this existing gap by assessing background noise levels in four commercial areas of Freetown, Sierra Leone: Aberdeen Market, Godrich Street, Jui Junction, and Sani Abacha Street. Using a calibrated handheld sound level meter, measurements were taken during daytime, evening, and nighttime periods over one week. Noise levels were analyzed using the day-evening-night equivalent continuous noise level (Lden) and statistical methods to assess compliance with World Health Organization (WHO) guidelines. Results revealed that all areas exhibit average noise levels above the WHO recommended limit of 70 dBA during daytime and evening hours, with Godrich Street and Aberdeen Market exhibiting the highest average daytime noise level (95.35 dBA) and the lowest average nighttime noise level (53.05 dBA) respectively. Godrich Street recorded the highest Lden value and shortest allowed exposure of 93.34 dBA and 1.17 hours respectively, indicating the most significant risk of prolonged exposure. Recommendations include creating designated quiet zones tailored to local commercial layouts, stricter enforcement of noise regulations, public awareness campaigns on hearing protection, and regular noise monitoring to guide urban planning. This study provides crucial insights for mitigating noise pollution and improving urban sustainability in developing nations.

The Noise Levels database has been developed at the Canadian Centre for Occupational Health and Safety for the computerized information system, CCINFO. The database documents measured noise levels from a broad spectrum of industrial settings. Industrial hygienists, noise control engineers, researchers, health and safety committee members, and appropriate government agency personnel are the main intended audience. Noise Levels is a textual‐numeric ‘source’ database of direct measurements, although bibliographic citations are also provided. The data for Noise Levels is gathered from both published and unpublished sources. Each record provides explicit information on the noise source (for example, piece of equipment), the industry, operation associated with the noise production, and the occupational categories. Additional information is provided on the type of noise, exposure duration per day, the presence of engineering controls, and the use of ear protection. Measurement data consists of one or more of the following: Sound Pressure Level (SPL) in dB(A), Time Weighted Average (TWA), Equivalent Continuous Noise Level (ECNL), and the octave band analysis. The primary goals of the database are to encourage sharing of industrial noise data and to promote standardized reporting of noise measurements.

Traffic noise has been recognized as a serious threat to the quality of life in most industrialised nations. Klang valley is rapidly emerging as industrialized and urbanized city and has started facing severe noise pollution problems. Urban noise quality assessment is studied in three residential areas; Desa Tun Razak, Kinrara Court and Taman Sentul Utama. Noise pollution indices of L10, L50, L90, Lmax and Lmin as well as equivalent continuous noise level (Leq) were measured for all dwellings. Noise indices results illustrate that Desa Tun Razak recorded the highest values of noise levels among three studied sites. Results also indicate that the highest Leq of 75.7 dB(A) was observed in Desa Tun Razak followed by 74.3 dB(A) in Kinrara Court, and 72.1 dB(A) in Taman Sentul Utama. The noise assessment study clearly reveals the alarming condition of noise pollution in residential areas of Klang Valley as the noise level measured exceeded permissible limit by WHO and Malaysia Guidelines.

Noise pollution arises as a severe problem to the community and ground transportation has highly impacted noise environment of the neighbourhood. In the present study, six stations were selected from three different locations in order to assess the traffic noise impact among residential area along Jalan Kluang, Batu Pahat. The objectives of this study focused on two main stages: (1) determination of noise indices; and (2) assessment of traffic noise impact. The noise indices such as equivalent continuous noise level (LAeq), noise level exceeded 10% (L10), 90% (L90) and the maximum noise level (LAFmax) of peak hours measurement time were determined using sound level meter (SLM) at all six stations. Besides, traffic noise index (TNI) and noise pollution level (LNP) were calculated based on the measured noise indices to expose the traffic noise impact. Overall, the result of the present study showed that residential area faces traffic noise disturbance partially whereby 50% of the stations exceeded the DOE standard which was 55dBA. Nevertheless, the residents living nearby Jalan Kluang are commonly facing traffic noise nuisance, but stations located further inside residential areas tend to have more residential background noises apart from traffic influence.

Noise pollution is one of the environmental factors that severely threaten humans’ mental, emotional, and physical health. One of the most significant sources of this pollution is the noise generated by traffic and urban transportation, mainly the urban railway. This paper assessed noise pollution at stations, passenger cars, and the train operator’s cabin. Four consecutive Baghdad subway stations were used to collect information. There were three modes of measurement: entering the station, stopping at the station, and leaving the station. Leq(equivalent continuous noise level) at station 3 is more significant than at three other stations, confirming that the initial hypothesis regarding the noise pollution rate was correct. Among the studied stations, Station 1 was the quietest. The stations with the highest and lowest Leqvalues are 3 and 2, respectively. The Leqvalues recorded in the cabin are within the permissible range. The highest Leqvalue measured at station 3 is 81.87 dB(A), and the lowest Leqvalue measured at station 2 is 61.24 dB(A). The operator’s cabin at station 3 has the highest measured Leqof 70.26 dB(A), and station 1 has the lowest measured Leqof 61.5 dB(A). While the measured value in the operator’s cabin was within the acceptable range, the noise levels in the wagons were above standard.

Chapter 9 Noise Pollution

This paper presents the research of noise level monitoring at the Zagreb Airport Ltd. The purpose of this paper is to show how the aircraft noise sources can be used as a tool for aircraft detection and for increasing flight safety. The noise measurement was made at the Zagreb Airport by using its professional noise monitoring system. The research has led to new findings, such as determining the aircraft model by measuring the noise level generated by an aircraft during final approach based on its frequency spectrum, as the connectivity from the airport’s side to the radar data was unavailable (only ATC). In addition, it is possible to determine the aircraft altitude and, perhaps most significantly, the increase of flight safety through the detection of potential failures on the aircraft structure and/or engine during the overflight of a noise monitoring terminal.

Continuous underwater noise has been monitored in the Slovenian sea near the lighthouse foundation at Debeli Rtič since February 2015, according to the EU Marine Strategy Framework Directive (MSFD). Anthropogenic noise sources (e.g. seawater densities, dredging activities and cleaning of the seafloor) and meteorological noise sources (e.g. wind speed and precipitation) were analysed in relation to the measured underwater noise levels using several graphical and statistical methods. The results of this study showed that average equivalent continuous underwater noise levels were, by 11 dB (L eq,63 Hz) and 5 dB (L eq,125 Hz), higher in the intervals when dredging activities took place than in the intervals when these activities were absent. Variation in underwater noise levels was partly related to the variation of the ship densities, which could be explained by the relatively small acoustic propagation in the shallow seawater. Precipitation level did not indicate any significant association with the variations in continuous underwater noise levels, though some larger deviations in the wind speed were found to be associated with the larger fluctuations in continuous underwater noise levels.

In order to investigate the physiological effects of airport noise exposure on organisms, in this study, we exposed Sprague-Dawley rats in soundproof chambers to previously recorded aircraft-related noise for 36 days. For comparison, we also used unexposed control rats. Noise was arranged according to aircraft flight schedules and was adjusted to its weighted equivalent continuous perceive noise level (LWECPN) of 75 dB and 80 dB for the two experimental groups. We examined rat behavior through open field experiments and measured the concentrations of serum neurotransmitters (norepinephrine (NE) and 5-hydroxytryptamine (5-HT)) by high performance liquid chromatography-fluorimetric detection (HPLC-FLD). Our results showed that rats that were exposed to airport noise of 80 dB spent more time in the central part of the open field, the number of cross-lattices they crossed reduced significantly (P<;0.05), and their frequency of grooming and defecation increased significantly (P<;0.05), compared to control animals. The concentrations of serum NE of experimental groups were higher than that of the control group, and a dose-effect relationship was seen between NE concentration and the intensity of noise exposure. On the contrary, serum 5-HT concentrations of the experimental groups were always lower than that of the control group.

Noise exposure is a distinct hazard during hand-held concrete grinding activities, and its assessment is challenging because of the many variables involved. Noise dosimeters were used to examine the extent of personal noise exposure while concrete grinding was performed with a variety of grinder sizes, types, accessories, and available dust control methods. Noise monitoring was conducted in an enclosed area covering 52 task-specific grinding sessions lasting from 6 to 72 minutes. Noise levels, either in minute average noise level (Lavg, dBA) or in minute peak (dBC), during concrete grinding were significantly (P < 0.01) correlated with general ventilation (GV: on, off), dust control methods (uncontrolled, wet, Shop-Vac, HEPA, HEPA-Cyclone), grinding cup wheel (blade) sizes of 4-inch (100 mm), 5-inch (125 mm) and 6-inch (150 mm), and surface orientation (horizontal, inclined). Overall, minute Lavg during grinding was 97.0 ± 3.3 (mean ± SD), ranging from 87.9 to 113. The levels of minute Lavg during uncontrolled grinding (98.9 ± 5.2) or wet-grinding (98.5 ± 2.7) were significantly higher than those during local exhaust ventilation (LEV) grinding (96.2 ± 2.8). A 6-inch grinding cup wheel generated significantly higher noise levels (98.7 ± 2.8) than 5-inch (96.3 ± 3.2) or 4-inch (95.3 ± 3.5) cup wheels. The minute peak noise levels (dBC) during grinding was 113 ± 5.2 ranging from 104 to 153. The minute peak noise levels during uncontrolled grinding (119 ± 10.2) were significantly higher than those during wet-grinding (115 ± 4.5) and LEV-grinding (112 ± 3.4). A 6-inch grinding cup wheel generated significantly higher minute peak noise levels (115 ± 5.3) than 5-inch (112 ± 4.5) or 4-inch (111 ± 5.4) cup wheels. Assuming an 8-hour work shift, the results indicated that noise exposure levels during concrete grinding in enclosed areas exceeded the recommended permissible exposure limits and workers should be protected by engineering control methods, safe work practices, and/or personal protective devices.

The acoustic radiation caused by periodic axial impacts on a cylindrical pipe pile of finite length is calculated. The axial velocity at all points on the pile surface is specified in terms of the excitation, the pile properties, and the ground impedance. It is assumed that the reflection of the structural wave at the pile-ground interface is a linear process, and that the radial pile velocity is simply related to the axial velocity through Poisson coupling. The pile motion is then used as a boundary condition for the acoustical space and the total acoustical power radiation and its spectral decomposition are predicted. Possible methods of noise control are discussed.

The invention of the telephone about 150 years ago extended the range of verbal communication between humans beyond the bounds given by the power of their voices. Using this technology, however, was – and still is – inherently connected with some inconveniences. The talkers have to hold a handset such that the loudspeaker is close to their ear and the microphone is adjacent to their mouth. Even then, speech quality is reduced and ambient noise may be picked up. Replacing the handset by a microphone and a loudspeaker now positioned a – short – distance from the talker increases the loss of the transmission loop by say 20 dB [6]. Furthermore, the level of ambient noise collected by the microphone is increased and the echo from the loudspeaker signal is picked up. Methods of acoustic echo and noise control aimed to remedy these disadvantages exhibit a long history. Originally, efforts were focussed on the development of hands-free telephone systems. In the following section we will highlight some of the important steps toward today’s systems. We will also point out that the developments were always linked to the technology available at the time of their proposal. This introductory chapter will close with an overview of important current developments reported in the following chapters of this book in detail by international experts in the field of acoustic echo and noise control.

For Gaussian noise with random or periodic impulsive interference, the conventional active noise control (ANC) methods with finite second-order moments may fail to converge. Furthermore, the intensity of impulsive noise typically varies over time in the actual application, which also decreases the performance of conventional active impulsive noise control methods. To address these problems, a novel adaptive state detector based post-filtering active control algorithm is proposed. In this work, information entropy with adaptive kernel size is first introduced into the cost function of a post-filtering algorithm to improve its tracking. To enhance the robust performance of adaptive filters when impulsive interference happens, a recursive optimal threshold selecting method is also developed and analyzed by statistical theories. Simulations show that the new method has fast tracking ability in non-impulsive noise environment and keeps robust when impulsive interference happens. It also works well for the impulsive noise of different degrees. Experiment results confirm the effectiveness of the proposed algorithm.