ArticlePDF Available

The Investigation of Noise Attenuation by Plants and the Corresponding Noise-Reducing Spectrum

Authors:

Abstract

As noise pollution is becoming more and more serious, many researchers are studying the noise attenuation effect provided by plants. This article examines six kinds of evergreens as research subjects so as to compare the different arrangements and densities of plants and their effect on noise attenuation. The authors studied the relationship between each of the plant's characteristics (the characteristics include leaf area, leaf fresh weight, leaf tactility, and leaf shape) and their average relative noise attenuation (deltaLAep). The authors then generated the noise-reducing spectrum of the six plants. The results show that there is a notable difference in noise-reducing effects for low frequency and high frequency (p < .05) when the plants are arranged differently. Also, every plant demonstrates a specific noise-reducing spectrum. By quantifying noise attenuation characteristics and abilities of plants, the authors combine noise attenuation species to achieve the mutual benefits of plant varieties and establish an ecotypic sound barrier model with effective density and arrangement.
... Although plant barriers do not have a high value of sound attenuation, they are normally more accepted by the population because they have a less visual impact [6,7]. The effect on noise attenuation of six types of plants (arrowwood, oleander, Chinese photinia, bamboo, red robin photinia, and deodar cedar) was evaluated by Fan et al. [8]. The results showed that the leaf shape, weight, and tactility affect the noise attenuation value, having each plant its own noise attenuation features. ...
... At low frequencies, there is no attenuation because the wavelength of the sound is such that the barrier is acoustically transparent, while at other frequencies the sound components are poorly attenuated. The attenuation of the corn plants as a temporary acoustic barrier is due to the sound scattering of trunks, branches, and by the viscous effect of the foliage, as has been reported in different studies [8,9]. ...
Article
Corn is a cereal imported into Europe from the Americas and is used for human and animal feed, but there are also industrial uses such as the production of ethanol, as a fuel for heating homes or to produce starch. Corn grows in the summer in areas where there is water. Corn is grown in many regions of the world and its production exceeds that of any other cereal in quantity. The corn plant can reach up to three meters in height, with a stem diameter of a few centimeters and with dense leaves longer than 30 cm and 10 cm wide. There are noisy activities where it is necessary to attenuate the noise produced to limit the effects of noise pollution. Some activities use temporary barriers depending on the processing cycle adopted. If noisy work is carried out during the summer season, corn rows of adequate width can be used as an acoustic barrier. In this paper, the possibility of using corn plants as an acoustic barrier is investigated. The acoustic measurements of the noise attenuation of corn rows of adequate width are described. Using a semi-spherical source placed on the ground, the acoustic attenuation due to the corn plants arranged in several rows for different distances from the sound source to the receiver was measured.
... Here, the use of plants is an effective option, as their uneven surface partially absorbs sound, which can significantly reduce noise pollution. However, not all plants are equally suitable for this task.Fan et al.[Fan+10] have investigated the relationship between tree characteristics -especially the properties of their leaves -and their ability to absorb sound.• Erosion Prevention. ...
... This may be because perceived pollution is related to individuals' sensitivity to pollution and acts as a mediator between measured pollution and psychological responses [41,42]. Green space may remove harmful gas and inhalable particles [43], attenuate noise pollution [44], and alter individuals' susceptibility to noise [45]. Green space may reduce both measured and perceived levels of air and noise pollution [46][47][48][49], which may further contribute to mental health [50][51][52]. ...
Article
Full-text available
Residential green space is among the most accessible types of urban green spaces and may help maintain mental health during the COVID-19 pandemic. However, it is insufficiently understood how residents use residential green space for exercise during the epidemic. The pathways between residential green space and mental health also merit further exploration. Therefore, we conducted an online study among Chinese residents in December 2021 to capture data on engagement with urban green space for green exercise, the frequency of green exercise, perceived pollution in green space, perceptions of residential green space, social cohesion, depression, and anxiety. Among the 1208 respondents who engaged in green exercise last month, 967 (80%) reported that green exercise primarily occurred in residential neighborhoods. The rest (20%) reported that green exercise occurred in more distant urban green spaces. The most common reasons that respondents sought green exercise in urban green spaces were better air and environmental qualities. Structural equation modeling (SEM) was then employed to explore the pathways between the perceived greenness of residential neighborhoods and mental health among respondents who used residential green space for exercise. The final model suggested that residential green space was negatively associated with anxiety (β = −0.30, p = 0.001) and depression (β = −0.33, p < 0.001), mainly through indirect pathways. Perceived pollution and social cohesion were the two mediators that contributed to most of the indirect effects. Perceived pollution was also indirectly associated with green exercise through less social cohesion (β = −0.04, p = 0.010). These findings suggest a potential framework to understand the mental health benefits of residential green space and its accompanying pathways during the COVID-19 era.
... Open pit plants, especially in proximity to residential areas, constitute a significant nuisance mostly, but not only, in terms of noise and dust emissions [4]. Operational practice shows that activities aiming at limitation of dust pollutants are more effective when performed closer to the source of pollution, while sound protective screens and natural barriers can be built along the mine boundaries [41]. ...
Article
Full-text available
This paper concerns investigations on dust particles and noise emission in mineral aggregate production. Two technological circuits of aggregate production were under investigation. The first circuit was based on a two-stage screening system, while the other was designed on a basis of a patented solution of regular aggregate production. Results of investigations show that an innovative circuit allows for reduction of screening stages which results in shortening the entire circuit. The quality of obtained products is better, while the environmental footprint of the latter circuit is lower. Results of investigations showed that reduction both in terms of dust particle emission and in noise generation was achieved.
... Nevertheless, maximum noise level had a significant negative influence on assemblage parameters and overall species composition in the sweepnet dataset, as shown by GLMMs and variation partitioning/ RDA. At distances larger than 10 m from the motorway, plantdwelling orthopterans may be more affected by traffic noise than geobiont and geo-chortobiont species, which could benefit from direct noise attenuation by overlaying vegetation (Fan et al., 2010;Ow & Ghosh, 2017). Conflicting effects of vegetation height and traffic noise, in addition to specific assemblage composition (see previous paragraph), may at least partly explain the lack of significant spatial differences in orthopteran assemblages sampled by sweep-net in the current study. ...
Article
• Major roads have become significant components of environmental change but their impacts on invertebrate assemblages are insufficiently understood, and therefore rarely considered in road-planning and management. • In the current study, we test (i) whether and how orthopteran assemblages change with distance from a motorway, and (ii) how road-induced changes in noise level, vegetation height and microclimate affect assemblage metrics and spatial distribution of orthopteran species. • In 2018, we sampled orthopterans at five distances from a motorway: 10, 25, 50, 100 and 500 m, in eight locations within homogeneous portions of a grassland habitat in Lika region, Croatia, using two sampling methods: pitfall trapping and sweep-netting. • Orthopteran abundance, species richness, true diversity and conservation value decreased at the sites closest to the motorway in the pitfall dataset, primarily due to negative responses of species with low-frequency acoustic signals. • Road-influenced vegetation height had a stronger overall impact on orthopteran assemblages than traffic noise and/or microclimate; increased diversity and conservation value at 25 m from the motorway suggest an effect similar to early stages of vegetation succession. • This study shows, for the first time, that a major road can induce changes in adjacent orthopteran assemblages, but negative impacts are confined to a narrow zone. • Our results indicate that road-induced changes in orthopteran assemblages could be more efficiently assessed using pitfall trapping than sweep-netting. • Increasing heterogeneity of roadside habitats by appropriate vegetation management could help mitigating negative road impacts on Orthoptera in the study area, while contributing to higher diversity of their assemblages.
... Although plant barriers do not have a high value of sound attenuation, they are normally more accepted by the population because they have a less visual impact [12,13]. The effect on noise attenuation of six types of plants (arrowwood, oleander, Chinese photinia, bamboo, red robin photinia, and deodar cedar) was evaluated by Fan et al. [14]. The results showed that the leaf shape, weight, and tactility affect the noise attenuation value, having each plant its own noise attenuation features. ...
Conference Paper
Corn is a cereal imported into Europe from the Americas. It is used for human and animal feed, but there are also industrial uses such as the production of ethanol, of fuel for heating homes, or the production of starch. Corn grows in the summer in areas where there is water. It is grown in many regions of the world and its production exceeds that of any other cereal in quantity. The corn plant can reach up to three meters in height, with a stem diameter of a few centimeters and with dense leaves longer than 30 cm and 10 cm wide. There are noisy activities where it is necessary to attenuate the noise produced to limit the effects of noise pollution. Some activities use temporary barriers depending on the processing cycle adopted. If noisy work is carried out during the summer season, corn rows of adequate width can be used as an acoustic barrier. In this paper, the possibility of using corn plants as an acoustic barrier is investigated. Acoustic measurements of the noise attenuation of corn rows of adequate width are described. Using a semi-spherical source placed on the ground, the acoustic attenuation due to the corn plants arranged in several rows for different distances from the sound source to the receiver was measured.
... In turn, acoustic research shows how structural components of vegetation buffers noise, and demonstrates that dense and diverse planting schemes provide particularly effective noise barriers [43,44]. Although urban populations may not always report strong satisfaction rates with environmental noise (reduction) in areas with greater land cover diversity [45], the physical processes through which vegetation attributes modify acoustics are nonetheless clear [43,46]. People's perceptions of the soundscapes of cities are thus important to consider, as the soundscape pleasantness of birds buffers the negative effects of traffic noise [47]. ...
Article
Full-text available
Purpose of review Biodiversity underpins urban ecosystem functions that are essential for human health and well-being. Understanding how biodiversity relates to human health is a developing frontier for science, policy and practice. This article describes the beneficial, as well as harmful, aspects of biodiversity to human health in urban environments. Recent findings Recent research shows that contact with biodiversity of natural environments within towns and cities can be both positive and negative to human physical, mental and social health and well-being. For example, while viruses or pollen can be seriously harmful to human health, biodiverse ecosystems can promote positive health and well-being. On balance, these influences are positive. As biodiversity is declining at an unprecedented rate, research suggests that its loss could threaten the quality of life of all humans. Summary A key research gap is to understand—and evidence—the specific causal pathways through which biodiversity affects human health. A mechanistic understanding of pathways linking biodiversity to human health can facilitate the application of nature-based solutions in public health and influence policy. Research integration as well as cross-sector urban policy and planning development should harness opportunities to better identify linkages between biodiversity, climate and human health. Given its importance for human health, urban biodiversity conservation should be considered as public health investment.
Article
Full-text available
Noise pollution is becoming more and more acute, and hence many researchers are studying the noise attenuation effect and prevention of noise. In this study an attempt has been made to find the reduction in noise levels at National Highway 45 near peerkankaranai in Chennai. Two sensitive places were selected along NH 45 by examining attenuation of noise by providing noise barriers in the form of concrete structures. The primary goal of this project was to identify innovative design of noise barrier that has the potential to be implemented in NH 45, Chennai. Based on the research and evaluation conducted for this study, it was recommended that two innovative barrier designs be implemented in Chennai. First, a noise prediction is made at the specified location on the highway under certain traffic conditions in order to determine the noise level by measurement and decide on the barrier requirement. The installation of sound barriers is feasible enough to cause a significant decrease in noise pollution at the roads. Considerable noise attenuation is achieved by providing concrete noise barrier. The paper provides Leq at the time of traffic data recorded was 105.1 dBA at NH45 and 91.108 dBA at NH5 during the time of observation at installation of barrier the values are 70.09 dBA 79.11 dBA, respectively. Noise reduction is possible and noise reduction is predominantly reduced by providing barrier.
Article
Full-text available
In this paper, we demonstrate that it is possible to improve the sound attenuation obtained from a mass of trees by arranging them in a periodic lattice. The outdoor experimental results have shown that the largest sound attenuation, within a certain range of frequencies, was obtained for a range of frequencies related to the array periodicity. This behaviour induces us to believe that these arrays of trees work like sonic crystals. The sound attenuation values obtained in outdoor experiments for some periodic tree configurations, especially at low frequencies (f500Hz), were far higher than those obtained from a typical green belt or forest. Therefore, these periodic arrays could be used as green acoustic screens.
Article
Full-text available
The biologic plausibility for noise stress-related cardiovascular responses is well established. Epidemiologic studies on the relationship between transportation noise and ischemic heart disease suggest a higher risk of myocardial infarction in subjects exposed to high levels of traffic noise. To determine the risk of road traffic noise for the incidence of myocardial infarction (MI), we carried out a hospital-based case-control study in the city of Berlin. We enrolled consecutive patients (n=1881), age 20-69 years, with confirmed diagnosis of MI from 1998 through 2001. Controls (n=2234) were matched according to sex, age, and hospital. Outdoor traffic noise level was determined for each study subject based on noise maps of the city. Standardized interviews were conducted to assess possible confounding factors and the annoyance from various noise sources. The adjusted odds ratio for men exposed to sound levels of more than 70 dB(A) during the day was 1.3 (95% confidence interval=0.88-1.8) compared with those where the sound level did not exceed 60 dBA. In the subsample of men who lived for at least 10 years at their present address, the odds ratio was 1.8 (1.0-3.2). Noise-exposed women were not at higher risk. The results support the hypothesis that chronic exposure to high levels of traffic noise increases the risk for cardiovascular diseases.
Article
Full-text available
It has been suggested that noise exposure increases the risk of hypertension. Road traffic is the dominant source of community noise exposure. To study the association between exposure to residential road traffic noise and hypertension in an urban municipality. The study population comprised randomly selected subjects aged 19-80 years. A postal questionnaire provided information on individual characteristics, including diagnosis of hypertension. The response rate was 77%, resulting in a study population of 667 subjects. The outdoor equivalent traffic noise level (Leq 24 h) at the residence of each individual was determined using noise-dispersion models and manual noise assessments. The individual noise exposure was classified in units of 5 dB(A), from <45 dB(A) to >65 dB(A). The odds ratio (OR) for hypertension adjusted for age, smoking, occupational status and house type was 1.38 (95% confidence interval (CI) 1.06 to 1.80) per 5 dB(A) increase in noise exposure. The association seemed stronger among women (OR 1.71; 95% CI 1.17 to 2.50) and among those who had lived at the address for >10 years (OR 1.93; 95% CI 1.29 to 2.83). Analyses of categorical exposure variables suggested an exposure-response relationship. The strongest association between exposure to traffic noise and hypertension was found among those with the least expected misclassification of true individual exposure, as indicated by not having triple-glazed windows, living in an old house and having the bedroom window facing a street (OR 2.47; 95% CI 1.38 to 4.43). The results of our study suggest an association between exposure to residential road traffic noise and hypertension.
Article
Transmission of random noise through dense corn, a dense hemlock plantation, an open pine stand, dense hardwood brush, and over cultivated soil was measured. The relation between attenuation and frequency in these diverse cases suggested models that permit the prediction of attenuation in any configuration of vegetation and soil. The corn crop had an excess attenuation of 6 dB/100 ft for each doubling of frequency between 500 and 4000 Hz. On the other hand, the stems of the hemlock, pine, and brush all reduced noise by only about 5 dB/100 ft at 4000 Hz. Bare ground attenuates frequencies of 200–1000 Hz, and the frequency of maximum attenuation depends on the soil permeability to air. Thus, tilling the soil reduced the frequency of peak attenuation from 700 to 350 Hz and increased maximum attenuation at 52 m from the source by nearly 80%. Furthermore, earlier conflicting reports of noise attenuation by vegetation appear reconciled if ground attenuation is taken into account. Scattering and ground attenuation are the principal factors in sound attenuation by vegetation. Both factors attenuate relatively less sound as distance from the sound source increases. Hence measurements far from the source can underestimate the effect of a narrow band of vegetation or soil.
Article
Many measurements of sound attenuation rates in forests have been made but there is little in common in the measuring procedures used or the results obtained. Consequently there is a considerable divergence of opinion on the effectiveness of vegetation as a noise control measure. In this paper the factors controlling the transmission of sound through vegetation are examined and the attenuation rates achieved in pine plantations are presented.
Article
The propagation of sound through a large number of scatterers (i.e., trees) is treated in a similar way to a classical diffusion problem. A general differential equation governing the sound intensity is derived which is valid under certain conditions, notably that the depth of the belt of vegetation is large, and absorption small. The predictions of this theory are compared with results derived from a small scale model study, and with some field measurements. They are also compared with published field data. The implications of some of the conclusions reached for the practical achievement of effective sound attenuation are pointed out. In general, it would appear that significant noise reductions may be achieved for a predominantly high frequency source if the existing ground cover is acoustically hard, or if there is no ``ground effect'' attenuation between source and receiver for some other reason. In other cases, the noise reduction will be much lower and may be negative.
Article
The effects of noise reduction of six tree belts were examined. An amplifier was placed in front of each tree belt, while a noise meter was placed at various heights and distances behind the tree belt. Net noise reduction effect termed as “relative attenuation” was obtained by subtracting the sound pressure level at each measurement site behind the tree belt from the sound pressure level at equal distances over open ground. Five parameters, including visibility, height, and width of the tree belt, height of receiver and noise source, and the distance between noise source and receiver, were studied. A multiple regression model demonstrating the order of importance of the five parameters in relation to relative attenuation was developed. The five parameters were then transformed into three-dimensionless parameters, i.e., h′: receiver and noise source height/tree height, d′: distance between noise source and receiver/tree height, and m′: belt width/visibility. By plotting the relative attenuation on the coordinate axis of h′, d′ and m′ and curve fitting, a three-dimensionless map of noise reduction by tree belts was formed. The map can be used as guidance in designing three belts for noise reduction in environmental planning.
Article
Measurements were made at a number of sites of road traffic noise propagating through belts of trees and bushes and above grass-covered ground, respectively. The belt widths were between 3 and 25 m. The distance from the road to the front of the belts also varied from site to site. The microphones were placed 1·5 m above the ground. A comparison between attenuations obtained, expressed as differences in equivalent constant A-weighted sound pressure levels, LAeq, showed no significantly higher attenuation values for propagation through belts of trees than for propagation above grass-covered ground. Only in the frequency range above 2 kHz were attenuations significantly higher through the belts of trees and bushes. The belts of trees selected consisted mainly of deciduous trees and bushes between 5 and 10 years of age. Such types and widths are representative of what could often be used in normal urban situations in an attempt to provide practical noise reduction. According to the results of this investigation, however, these do not significantly reduce LAeq 1·5 m above the ground. Planting of belts of trees and bushes between roads and dwellings might influence the environmental quality of residential areas due to nonacoustic factors or reduce nuisance due to spectral changes not affecting LAeq. This has not been investigated.
Article
This study investigates the noise reduction effect of 35 evergreen-tree belts. A point source of noise was positioned in front of the tree belts and the noise level at various points in the belts was measured with a noise meter. Factors important for noise reduction include visibility, width, height and length of the tree belts. Stepwise regression was employed to examine the factors associated with noise reduction. A negative logarithmic relationship between the visibility and relative attenuation was found. A positive logarithmic relationship between relative attenuation and the width, length or height of the tee belts was also found. A map showing the relationship between visibility together with width was plotted. The map provides some practical suggestions concerning design of tree belts for noise reduction.
Article
The adverse effects of long-term exposure to a high volume of road traffic were studied in socio-acoustic surveys in 1997 and in 1999 after a substantial reduction in road traffic. The results obtained in 1997 showed a similar response pattern as in previously performed studies in the area in 1986 [Ohrström, J. Sound Vib. 122, 277-290 (1989)]. In 1999, road traffic had been reduced from 25000 to 2400 vehicles per day, and this resulted not only in a large decrease in annoyance and activity disturbances, but also in a better general well-being. The results suggest that a reduction in both noise and other pollutants from road traffic contribute to these effects. To be able to use the outdoor environment and to have the possibility to keep windows open is essential for general well-being and daily behavior, which implies that access both to quiet indoor and outdoor sections of the residency is of importance for achievement of a healthy sound environment. More knowledge of long-term health consequences of exposure to noise and simultaneous pollutants from road traffic is needed. Studies should focus more on "softer" health outcomes and well-being than hitherto and preferably be performed in connection with traffic abatement measures.