The influence of preconceptions on perceived sound reduction by environmental noise barriers

The paper presents research that answers three main questions: (1) Do preconceptions held about the constituent materials of an environmental noise barrier affect how people perceive the barrier will perform at attenuating noise? (2) Does aesthetic preference influence the perception of how a barrier will perform? (3) Are barriers, which are deemed more aesthetically pleasing, more likely to be perceived as better noise attenuators? In a virtual reality setting with film to improve the contextual realism of the intersensory interaction test, participants were required to compare the perceived effectiveness of five standard 'in-situ' noise barriers, including concrete, timber, metal, transparent acrylic and a vegetative screen. The audio stimulus was held at a constant sound pressure level (SPL), whilst the visual stimulus changed, as the influential factor. As the noise levels projected during the study were held constant, it was possible to attribute the participants' perception of noise attenuation by the barriers, to preconceptions of how the varying barrier material would attenuate noise. There was also an inverse correlation between aesthetics and perception of how a noise barrier would perform. The transparent and deciduous vegetation barriers, judged most aesthetically pleasing, were judged as the least effective at attenuating noise. (c) 2010 Elsevier B.V. All rights reserved

An Assessment of Psychological Noise Reduction by Landscape Plants

The emphasis in the term ‘Green Transportation’ is on the word ‘green’. Green transportation focuses on the construction of a slow transport system with a visually pleasing, easy and secure trip environment composed of urban parks, green roadside spaces and some other space that is full of landscape plants. This trip environment encourages residents to make trip choices that reduce fuel consumption and pollution and is one of the most important ways of popularizing green transportation. To study the psychological benefits provided by urban parks and other landscape environments, we combined a subjective approach (a questionnaire) with an objective quantitative approach (emotional tests using an electroencephalogram; EEG). Using a questionnaire survey, we found that 90% of the subjects believed that landscape plants contribute to noise reduction and that 55% overrated the plants’ actual ability to attenuate noise. Two videos (showing a traffic scene and a plant scene) were shown to 40 participants on video glasses. We detected and recorded EEG values with a portable electroencephalograph, and a comparison between the results of the two groups revealed that there was a highly significant asymmetry between the EEG activity of the vegetation scene and traffic scene groups. The results suggest that the emotions aroused by noise and visual stimuli are manifested in the synchronization of beta frequency band and the desynchronization of alpha frequency band, indicating that landscape plants can moderate or buffer the effects of noise. These findings indicate that landscape plants provide excess noise attenuating effects through subjects’ emotional processing, which we term ‘psychological noise reduction’

Effects of Changed Aircraft Noise Exposure on Experiential Qualities of Outdoor Recreational Areas

The literature indicates that sound and visual stimuli interact in the impression of landscapes. This paper examines the relationship between annoyance with sound from aircraft and annoyance with other area problems (e.g., careless bicycle riding, crowding, etc.), and how changes in noise exposure influence the perceived overall recreational quality of outdoor recreational areas. A panel study (telephone interviews) conducted before and after the relocation of Norway’s main airport in 1998 examined effects of decreased or increased noise exposure in nearby recreational areas (n = 591/455). Sound from aircraft annoyed the largest proportion of recreationists, except near the old airport after the change. The decrease in annoyance with sound from aircraft was accompanied by significant decreases in annoyance with most of the other area problems. Near the new airport annoyance with most factors beside sound from aircraft increased slightly, but not significantly. A relationship between aircraft noise annoyance and perceived overall recreational quality of the areas was found

On the study of the effects of sea views, greenery views and personal characteristics on noise annoyance perception at homes

Noise annoyance has caused significant adverse impacts on human beings and numerous efforts have been spent on mitigating annoyance problems. Natural greenery has been shown to be able to moderate annoyance problems at home but this conclusion was drawn without properly controlling the potential confounding factors. Furthermore, few have explored the moderation effect of a sea view. Accordingly, this study formulated a multivariate model to examine the impacts of natural views as well as personal characteristics on annoyance perception. A housing estate was selected in Hong Kong as the survey site for which some of the residents were exposed to greenery views, sea views, or both from their homes. Eight hundred and sixty-one responses were collected via questionnaire surveys and analyzed using an ordered logit model. The results suggest that both a greenery view and a sea view can moderate annoyance responses. Several individual’s personal characteristics are found to affect individuals’ annoyance perception. The duration of time spent daily at home is shown to have an influence on the moderation impact exerted by a greenery view, while the age of an individual is shown to have an influence on noise moderation effect exerted by a sea view.Department of Building Services Engineerin

Perception of urban park soundscape

A number of studies have been initiated to explore how to improve the soundscape quality in urban parks. However, good soundscape quality in parks cannot be provided without a thorough understanding of the complex relationships among sound, environment, and individuals. As acoustic comfort is considered to be an important outcome of soundscape quality, this study investigates the relative impacts of the factors influencing acoustic comfort evaluation by formulating a multivariate ordered logit model. This study also explores the inter-relationships among acoustic comfort evaluation, acceptability of the environment, and preference to stay in a park using a path model. A total of 595 valid responses were obtained from interview surveys administered in four parks in Hong Kong while objective sound measurements were carried out at the survey spots concurrently. The findings unveil that acoustic comfort evaluation, besides visual comfort evaluation of landscape, also plays an important role on users’ acceptability of the urban park environment. Compared with all the studied acoustic related factors, acoustic comfort evaluation serves as a better proxy for park users’ preference to stay in urban parks. Hearing the breeze will significantly increase the likelihood of individuals in giving high acoustic comfort evaluation. Conversely, hearing the sounds from heavy vehicles or sounds from bikes will significantly reduce the likelihood in giving a high acoustic evaluation.Department of Building Services EngineeringDepartment of Mechanical Engineerin

Percepção sonora e conforto acústico em espaços urbanos do município de Belo Horizonte, MG

Resumo O presente artigo tem como objetivo apresentar e analisar as respostas dos usuários de espaços urbanos abertos com relação à percepção do volume sonoro e à avaliação de conforto acústico, com base em dados coletados em campo durante o ano de 2013, em duas praças do município de Belo Horizonte, MG. Durante os levantamentos, dados acústicos foram medidos simultaneamente à aplicação de questionários, utilizados para coleta de variáveis subjetivas e individuais. O LAeq,T foi o índice utilizado para caracterização dos ambientes sonoros. Os resultados demonstram que, sob as mesmas condições acústicas, tanto no que diz respeito à percepção do volume sonoro quanto à avaliação de conforto acústico, os indivíduos tendem a ser mais tolerantes na praça que possui a melhor ambiência e as melhores condições de conforto térmico. As faixas de percepção do volume sonoro definidas neste estudo foram: Baixo, LAeq < 35 dB(A); Normal, 36 < LAeq < 67 dB(A); Alto, LAeq > 68 dB(A). Com relação à avaliação do conforto acústico, as faixas definidas foram: Confortável, LAeq < 67 dB(A); e Desconfortável, LAeq > 68 dB(A). Espera-se que esses resultados contribuam para um maior entendimento das questões relativas ao conforto acústico urbano

Perceived integrated impact of visual intrusion and noise of motorways: Influential factors and impact indicators

Motorways are often seen as intrusive to both landscape and soundscape, and recent studies on multisensory perception suggest that an integrated assessment of the environmental impacts is necessary. This paper investigates the effects of traffic condition, distance to road and background landscape on the perceived integrated impact of noise and visual intrusion of motorways, and explores if noise exposure can be a powerful indicator for the perceived integrated impact. Six traffic conditions, consisting of three levels of noise emission × two levels of heavy good vehicle percentage in traffic composition, two types of background landscape and three distances to road, were designed as experimental scenarios, and created using computer visualisation and edited audio recordings. A laboratory experiment was carried out to obtain ratings of perceived environmental quality of each experimental scenario. The results show that traffic volume as expressed by noise emission level strongly influenced the perceived integrated impact, whereas traffic composition did not make noticeable differences. Distance to road was the second most influential factor, followed by background landscape. A regression model using noise level at receiver position and type of background landscape as independent variables was developed and can explain about a quarter of the variation in the perceived integrated impact

Influence des informations visuelles sur la caractérisation de la qualité acoustique de l'environnement urbain

CERGY PONTOISE-BU Neuville (951272102) / SudocCLERMONT FD-IFMA (630142301) / SudocSudocFranceF