Noise generated by low-altitude aircraft movements reaches levels higher than many other anthropogenic noise sources. How birds respond to these acute noise levels is, to date, poorly understood. This thesis provides some of the first data on how noise generated by aircraft affects avian communities and communication. Firstly, point counts conducted around Manchester airport show there is no effect of increasing noise levels on beta diversity. In addition, results show the density and abundance of the two most abundant species and the number of detections for the five most common species was also unaffected. Secondly, comparisons of the songs of the abundant chiffchaff reveal that airport birds use lower frequency songs than control birds. This finding was replicated in two countries. Additionally, the songs of airport birds in the UK are longer and slower than control birds. These findings may be explained by birds that are found close to airports are suffering from Noise Induced Hearing Loss (NIHL). This was supported when comparing the responses of airport and control chiffchaffs to territorial songs; airport chiffchaffs were more aggressive, attacking the speaker 5 times more than control birds. An explanation for this is that as an artefact of NIHL, airport birds perceive songs differently to those in the control site. Finally, physiological stress induced by aircraft noise was investigated. There were no differences in corticosterone levels, a proxy for measuring stress levels, between 11-day old blue tit chicks exposed to noise treatments and control chicks. These findings suggest that pre-fledging blue tit chicks do not perceive anthropogenic noise as an environmental stressor. Whilst the work in this thesis does not detect an effect of aircraft noise on the species community or corticosterone levels, it does provide evidence consistent with the loss of hearing in birds as a consequence of anthropogenic noise exposure.

Acoustic noise problems are encountered in many fields and are very often undesirable. The localisation of sound sources is the first step 10 reducing noise problems. In this thesis, the ability and feasibility of an acoustic camera in this regard is demonstrated The acoustic camera deals with the problem of sound sources coming from different directions by estimating the sound contributions incident to the acoustic camera. One example of an aero-acoustic noise problem is an air plane with its air foil. These cause unwanted noise due 10 the flowed air. Or another example is the current collector on trains which causes unwanted noise as well as affecting driving. Another problem, dealt with later in this thesis, is a cylinder flowed by air in a wind tunnel. A practical case 0/ this problem is a car antenna in the form of a cylinder; this causes noise due to the driving wind Fans can be optimised for aero-acoustics as well - an example is a cooling fan in a computer, or larger fans for air conditioners that can transport the noise over the whole tunnel in which they are built. Some processing techniques are used and implemented in the acoustic camera. The first technique is the "classical" Delay-and-Sum Beam/arming technique and the improved orthogonal beamforming, with the ability to separate non-correlated sound sources in a Single measurement. The second technique is based on the decomposition of the Eigenvalues of the cross spectral matrix. In addition to the experimental section of this thesis, the results are compared to a simulation, where a flowed object measured with the acoustic camera is compared to a suitable simulation with the same parameters like dimensions and velocity. Here f/owed means that a suitable object, a cylinder for example, is placed in the wind tunnel and flowed by air. The outcome of this thesis is the analysing of a flow induced problem, a fan for example. First steps were done with 2D flow simulations of a cylinder to become familiar with the topic program and implementing MATLAB® code to process the points of interest. This analysing could be done with a simulation or with the acoustic camera. The aim of this work is concerned with sound sources and the mechanism behind it. Suitable aero-acoustic experiments were chosen that can be analysed with the acoustic camera and with numerical simulation as well. With the acoustic camera, these sound sources can be visualised using the beamforming method A similar procedure should be done to the numerical simulations. These simulations are done and the sound sources are visualised there as well by rebuilt an array of microphones, which acts as acoustic camera, in the numerical simulations.

This study explores the effects of natural and sustainable materials including vegetation, green roof systems and green walls on outdoor noise control in urban areas. The concept of this study starts with a hypothesis that well-planned use of the natural materials on building and urban surfaces can achieve useful reductions in noise levels and reverberation in urban spaces. Firstly, this study examines random-incidence absorption and scattering coefficients of vegetation through a series of measurements in a reverberation chamber in order to characterise the effects of various designable factors such as soil depths, soil water content and vegetation densities. This data is used later in acoustic computer simulations. To quantify the scattering effect of trees and to allow including it in numerical predictions, a series of measurements are carried out for individual trees in an open field. Green roof systems are placed on a low profiled structure to examine sound transmission through the vegetated low barrier. To suggest noise abatement schemes in relatively small urban spaces, the acoustic effects of landscape designs using vegetation in a courtyard are studied through a case study. As a preliminary study on the noise reduction effect of vegetation in relatively large urban spaces, field measurements are carried out at outdoor spaces in high-rise apartment complexes. Based on the measurement results, the noise reduction effect of vegetation in apartment complexes is also predicted. The overall results for each research topic can be summarised as follows: It is shown that low-growing vegetation can be an effective measure for absorbing/scattering sound energy, especially at high frequencies. Results of field measurements show that tree reverberation exerts an influence only on frequencies above 1 kHz. At 4 kHz, RT (reverberation time) can be as long as 0.28 sec. Measurements made near the same deciduous tree with and without leaves indicate that leaves increase reverberation at 4 kHz by 0.08 sec. The results on sound transmission over the low barrier with green roof systems suggest that SPL attenuation increases with the increasing green roof areas. The extra SPL (sound pressure level) attenuation caused by green roof systems could be up to 9.5 dB at certain frequencies. With well-planned application of landscape designs in a courtyard, speech levels and RT at 500 Hz are decreased by 9.3 dBA and 81 %, respectively. In outdoor spaces of apartment complexes, RT is generally rather long, over 4 sec at 500 Hz, influenced by many factors such as openness, source-receiver distance and building height. In terms of SPL distribution, the measured SPL is up to 8 dB higher compared to the semi-free field situation. It is also found that vegetation at the apartment complex can be effective in reducing RT by 0.95 sec (46 % decrease).

The valuation of environmental impacts through Choice Experiments (CE) has been increasing applied in order to estimate the cost of environmental externalities. While this valuation technique offers several advantages over other methods, a crucial problem lies in representing the attributes in a manner that can be easily understood by the respondents. Another problem associated with this valuation technique is the assumption that respondents have known and consistent preferences. This thesis relaxes the restraint by allowing respondents to indicate their level of preference certainty. The effect of different attribute representation techniques especially in context of traffic noise is also examined in relation to the level of preference certainty, while the effect of preference elicitation methods on certainty levels is also scrutinised. Several CE surveys were conducted to evaluate the impact of traffic noise under a residential setting. In order to examine the effects of attribute representation method on the respondents, two different surveys were undertaken using the location and the linguistic representation techniques. This has been carried out in conjunction with three different methods of preference elicitation: the binary choice, one stage Likert and two stage Likert methods. Thus for each of the attribute representation methods, different preference elicitation techniques have been employed. The main purpose of the analyses has been to examine the variation in error structure and the need for error flexibility due to the different preference elicitation and representation techniques. The results reveal that these components of choice design significantly affect respondents’ decision making and subsequent valuation. Moreover, different methods of representation also influence the level and cause of preference uncertainty as well the decision process.

No description available.

Noise is considered to be a physical form of environmental pollution which can influence the health of exposed persons. Excessive exposure to noise can interfere with performance at work and with the ability to relax or sleep. Also it may impair hearing and it can evoke other physiological and pathological symptoms to the detriment of health. The sources of noise may be local or general. Industrial processes are an important source of indoor or localised noise. Persons exposed to noise as a consequence of their employment are legally protected to some extent by European Directives and National Regulations which limit the maximum permissible noise levels to 85-90dB. A research project was launched with the full co-operation of the Don and Low Group of Companies, Forfar and Perth, Scotland. Study indicates that the proportion of employees who have noise-induced hearing loss is higher amongst those who work in higher than 85dB, (e.g. Group 1 < 85dB-11%; Group 2 85<90dB-44%; Group 3 90<95dB-44%; Group 4≥95dB-39% = 138% in total). In all groups social and economic status, sex, age and average number of years' service are almost identical. In general, the study indicates a higher number of employees suffered from ear problems between groups exposed to 85dB and more, (e.g. perforated eardrum, noise tinnitus, vertigo, wax in ears). The danger of noise has been studied in detail regarding the general health of employees as follows: 1. Sleep disturbance It appeared that most of the cases who suffered from sleep disturbance were found amongst employees exposed to greater than 85dB, averaging about 33%. On the other hand, only 8% of the employees in category <85dB complained of sleep disturbance. 2. Blood Pressure According to job categories 10% of employees had heart problems in job category higher than 85dB, but only one case reported heart problems in job categories less than 85dB. 3. Stress Smoking was one of the subjects studied in detail in this project and the results were significant. An average of 40% of employees were smokers among groups exposed to higher than 85dB compared to 10% of smokers among employees exposed to less than 85dB. Industrial accidents occur at a higher rate among employees who worked in noisy environments (~85dB) with regard to reported or unreported accidents. From the result of the research, industrial noise should be studied in a more comprehensive way to measure all effects of noise regarding employees health by using the statistical data and always noise should be controlled at source. Industrial noise is still a major danger to employees. From the results in this study it appears there is a need for more co-operation between employer and employee and not just depend on the health and safety regulations and try to solve the problem.

In der Broschüre werden ausgewählte Praxisbeispiele von Lärmminderungsmaßnahmen aus der kommunalen Lärmaktionsplanung oder damit eng verzahnter Planungen vorgestellt. Damit erhalten Gemeinden Impulse für ihre eigene Lärmaktionsplanung. Die Projekte werden in Kurzform beschrieben, zahlreiche Querverweise ermöglichen weitergehende Information.

Durch die Vorstellung ausgewählter Beispiele, deren Realisierung aus kommunalen Lärmaktionsplänen oder damit eng verzahnten Planungen resultiert, werden mit dieser Broschüre Anregungen und Impulse für den Prozess der Lärmaktionsplanung aufgezeigt. Das breite Spektrum und die Vielfalt möglicher Maßnahmen sollen dazu anregen, bei der Lärmaktionsplanung auch neue Wege zu beschreiten. Soweit möglich wurde auf Beispiele aus Sachsen oder den angrenzenden Bundesländern zurückgegriffen. Bewusst werden die vorgestellten Maßnahmen nur knapp skizziert. Über die Literatur- und Internetquellen am Ende der Broschüre können Interessenten weitergehende Informationen zu den vorgestellten Maßnahmen und Strategien beziehen.

Aircraft noise, for the first time in Thailand, has gained public attention as a significant environmental issue since Bangkok s Suvarnabhumi Airport opened in 2006. Residential areas around the airport are expanding rapidly while local residents are protesting about the noise from the new airport which suggests a tension between economic benefits and environmental problems at the airport. This thesis sets out to obtain valuation of aviation externalities at Suvarnabhumi airport using the stated choice method. It is the first study to obtain and compare valuations from perspectives of the polluters (Thai air passengers) and the polluted (residents) at the same airport. Furthermore, this is the first study to obtain a valuation of local impacts from aircraft operations and from air passengers. It starts by investigating perceptions and awareness of the benefits and costs of aviation activities among Suvarnabhumi s residents and passengers using focus groups and questionnaires. It then employs the stated choice method to elicit willingness-to-pay (WTP) and willingness-to-accept (WTA) values of aviation externalities. The results found that the perceived environmental problems at Suvarnabhumi airport are in line with the literature mainly involving aircraft noise and its effects. This study also found that the development of the airport and surrounding area, while creating business and employment opportunities, has also created traffic and flooding problems. In terms of air pollution from aircraft, residents concerns are confined to local impacts from aircraft. Thai air passengers were found to be more concerned with engine pollution than noise. These findings were reflected in the values obtained. Two stated choice designs were used to elicit values. The first rerouted the aircraft flight path away from residents homes thus reducing aircraft noise and pollution in the area. This design also included travel time to place of work or to the shops. The rerouting attribute was not statistically significant. However, the travel time attribute reveals that residents were willing to accept 14.23 baht a month to have their travel time to work or shopping increased by 1%. The second design was used to obtain and compare values between Suvarnabhumi s residents and air passengers. In this design, attributes for aircraft noise, local air pollution and carbon emissions were included. Residents willingness to pay to reduce aircraft noise by 1% is 104.76 baht/year whereas passengers are willing to pay less, at 70.63 baht per year. Air passengers place a higher value on local air pollution than the residents. Passengers are willing to pay 97.72 baht to reduce local pollution by 1% per year, whereas residents willingness to pay is 45.36 baht. Lastly, passengers WTP to offset carbon is 473.26 baht per flight, whereas residents carbon offset coefficient is not statistically significant. The obtained values are well within the range of existing studies on aircraft noise and carbon emission valuations. Findings from this study suggest that current mitigation measures at Suvarnabhumi airport are still inadequate. There are areas where the situation is likely to get worse given the rapid growth in aviation activities and urban development at the airport. The values from this study may be used to help form the basis of fairer and more transparent compensation system alongside an operational mitigation policy to address aviation impacts. On the passenger side, the stated willingness-to-pay to reduce the impact gives an opportunity for the Thai aviation industry to promote an environmentally friendly behaviour among the travelling public.

In der Broschüre werden ausgewählte Praxisbeispiele von Lärmminderungsmaßnahmen aus der kommunalen Lärmaktionsplanung oder damit eng verzahnter Planungen vorgestellt. Damit erhalten Gemeinden Impulse für ihre eigene Lärmaktionsplanung. Die Projekte werden in Kurzform beschrieben, zahlreiche Querverweise ermöglichen weitergehende Information.