Dans le cadre de cette maîtrise, Mélanie Frisoli s’est penchée sur un travail de compositions spatiales qui impliquent des dispositifs de haut-parleurs conséquents (de 16 à 64 haut-parleurs) et qui s’inspirent fortement de l’esthétique du paysage sonore et des théories de l’écologie sonore. Le médium multiphonique en trois dimensions (proche de notre vécu sensoriel quotidien) s’est avéré un support de choix pour expérimenter la sensibilisation aux bruits et à notre environnement sonore via la composition musicale. Mélanie a également tenté de comprendre pourquoi la spatialisation pouvait être intéressante et ce que ce paradigme proposait d’original et de sensible par rapport à la composition stéréophonique. En parallèle, la composition musicale de paysage sonore a été explorée avec tout ce qu’elle implique en tant que posture artistique. L’ensemble de ces questionnements et de ces recherches ont permis d’élaborer des stratégies compositionnelles pour la mise en espace du son sous des dômes de haut-parleurs. Sont ainsi nées trois œuvres acousmatiques (fixes sur support) et une performance en direct qui explorent les thématiques de l’espace, de la pollution sonore, de l’immersion et de la conscientisation de l’écoute. Enfin, différentes technologies pour la spatialisation du son sont présentées dans ce mémoire, avec un intérêt particulier apporté à celle utilisée dans ce travail de recherche-création. Mélanie Frisoli a également développé cinq outils informatiques afin de mieux appréhender le travail de spatialisation et de faciliter l’intégration du paramètre d’espace au processus de composition. / As part of this master’s degree, Mélanie Frisoli worked on spatial compositions that involve substantial loudspeaker devices (16 to 64 loudspeakers) and are strongly inspired by the aesthetics of soundscape composition and the theories of sound ecology. Due to its close connection to our daily sensory experience, the three-dimensional multiphonic medium was ideal for experiencing awareness of noises and our sound environment through musical composition. She also attempted to understand why spatialization could be interesting and what was original and sensitive compared to stereo compositions. In parallel, the musical composition of soundscape was used to study what it implies as an artistic posture. All these questions and research led to the development of compositional strategies for setting sound in space under loudspeaker domes. Three acousmatic works (fixed on support) and a live performance were created, all of which explore themes such as space, sound pollution, immersion, and awareness of listening. Finally, Mélanie presented various existing technologies for sound spatialization in this thesis, but mainly focused on the one used in this research-creation work. She also developed five computer tools to support her work in spatialization and facilitate the integration of the space parameter within the composition process.

Whereas commercial aviation is attempting to achieve the reduction of its substantial carbon footprint, general aviation’s (GA) climate change contribution is negligibly small, which is why the sector is facing other sustainability challenges mainly entailing the operation of dated technology and aircraft, increasing regulatory constraints, rising costs, noise emissions, and popular discontent, as well as remaining the last mobility sector in the world to still use leaded fuels. Throughout recent years, there have been remarkable sustainability trends in GA as well as heightened efforts to improve its emissions profile (noise, pollutants, CO2) and environmental reputation, for instance by the increased use of electric aircraft, especially for private pilot training. From a sociotechnical perspective, this mixed-methods study highlights current sustainability challenges and trends in GA as well as potential pathways towards more sustainable GA and private pilot training. Eight in-depth semi-structured interviews with Swiss and international GA stakeholders were complemented with a bilingual representative quantitative online survey (N=427) among Swiss GA stakeholders, a comparative CO2 analysis showing the emissions advantages and feasibility limits of supplementing private pilot training with lessons using electric aircraft, as well as participant observation. The data show that most Swiss GA stakeholders have increased environmental awareness and are concerned about sustainability and the environment both, in flight and other activities. Although the majority advocates for sustainable development in GA there are not one but many challenges and obstacles to a more sustainable GA. The largest challenges are the abatement of noise emissions and the facilitation of the leaded aviation gasoline (AVGAS 100LL) phaseout. The most pertinent obstacles towards sustainable GA innovation are said to be bureaucracy, overregulation and reluctance in the civil aviation authorities, high costs, averseness to risk and innovation, as well as a trend of decline in GA activity due to continuous demographic change. No single sustainability pathway but rather a mix of immediate and long-term sustainability measures was identified. Despite its current limitations, electric aviation proves to be one of the most feasible pathways to sustainable private pilot training. For more sustainable GA, the use of more fuel-efficient planes and available unleaded fuels, propeller, and muffler retrofits, as well as is feasible short- and midterm measures. In the long run, electric and hybrid aviation as well as bio- and synfuels are likely to become attractive options for GA. The study shows the importance of sustainable development in GA and private pilot training, not because it will majorly contribute to climate change mitigation, but because it will ensure the improvement of its negative environmental reputation and societal acceptance, which will be vital to ensuring the survival of the GA sector.

Thesis (MA)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The noise produced by aircraft during operations around airports represents a senous social, technical, economic and environmental problem which is only going to get worse as air traffic volumes increase. Rapid urbanisation, development encroachment and poor planning in the past have resulted in noisy airport runways being situated too close to residents' living space. Rapid industrial growth and lack of funding exacerbate noise problems in developing countries. Moreover, developing countries and especially South Africa tend to have moderate climates and open-window living, which makes insulation an ineffective solution to the noise problem. This study aims at employing GIS to establish the potential noise exposure of various sensitive land use categories and population groups in the noise-controlled area at Cape Town International Airport. Firstly, options for the demarcation of a noise-controlled area were evaluated. Thereafter, incompatible land uses and priority areas for land use compatibility projects were identified and recommendations made for urban renewal projects for these areas. Lastly, the noise-exposed population were profiled according to vulnerability characteristics and vulnerable groups identified and located. A recommendation was made that Cape Town International Airport set up an interactive map-based website to disseminate information to the public about noise and any other important issues concerning the airport. An Internet GIS application would empower citizens by providing them with a dynamic and interactive tool for improved public participation and a better understanding of the potential environmental and socio-economic effects of the airport. Noise complaints could also be investigated through the website and prompt feedback given to the communities complaining about aircraft noise. At the local community level where people are being annoyed every day and night resulting in negative health effects, the problem of aircraft noise demands urgent attention, and measures should be put in place to reduce vulnerability to noise and improve the overall quality of life of noiseweary residents. Keywords: aircraft noise, noise mapping, noise-controlled area, noise contours, land use compatibility, noise exposure / AFRIKAANSE OPSOMMING: Die geraas veroorsaak deur vliegtuie by lughawens bied ernstige sosiale, tegniese, ekonomiese en omgewingsprobleme, wat net erger gaan raak namate vlugverkeer toeneem. Snelle verstedeliking, ontwikkelings-oorskryding en swak beplanning in die verlede het veroorsaak dat raserige aanloopbane te nabyaan mense se leefruimte gebou is. Vinnige industriële groei en 'n tekort aan befondsing vererger geraasprobleme in ontwikkelende lande. Bowendien het ontwikkelende lande, en veral Suid Afrika, 'n matige klimaat en oop-venster-leefwyse wat isolering 'n oneffektiewe oplossing maak vir die geraasprobleem. Hierdie studie het ten doelom GIS te gebruik om die potensiële geraas blootstelling van sensitiewe grondgebruike en bevolkingsgroepe in die geraas-kontrole area by Kaapstad Internasionale Lughawe vas te stel. Eerstens is opsies vir die afbakening van die geraas-kontrole area geëvalueer. Daaropvolgend IS onversoenbare grondgebruike en prioriteitsareas VIr grondgebruikversoeningsprojekte geïdentifiseer en aanbevelings gemaak vir stedelike vernuwingsprojekte vir hierdie areas. Laastens is 'n profiel daargestel van die geraas-blootgestelde bevolkings volgens kwesbaarheidskenmerke en kwesbare groepe is geïdentifiseer en hulligging aangedui. 'n Voorstel is gemaak dat Kaapstad Internasionale Lughawe 'n interaktiewe kaart-gebaseerde webwerf in werking moet stelom inligting oor geraas- en ander belangrike probleme in verband met die lughawe beskikbaar te stel vir die publiek en ander belanghebbendes. 'n Internet-GIS toepassing sal mense bemagtig deur hulle te voorsien van 'n dinamiese en interaktiewe meganisme wat sal lei tot beter gemeenskapsdeelname en ook 'n beter begrip van die potensiële omgewings- en sosio-ekonomiese uitwerking van die lughawe. Klagte oor geraas kan ook deur die webwerf hanteer en ondersoek word, en verder hulp verleen word deur vinnige terugvoering aan die gemeenskap wat die klagtes gelê het. Op plaaslike gemeenskapsvlak, waar mense elke dag en nag geïrriteerd raak en waar dit dan kan lei tot negatiewe gesondheidsinvloed, sal die probleem van vliegtuiggeraas dringend aangespreek moet word, en stappe geneem word ten einde kwesbaarheid van inwoners teenoor vliegtuiggeraas te verminder. Dit sal dan lei tot die algehele verbetering van die lewensgehalte van geraas-moeë Inwoners. Sleutelwoorde: vliegtuiggeraas, geraaskartering. geraas-kontrole area, geraaskontoere, grondgebruik versoenbaarheid, geraas blootstelling

O presente trabalho consiste em uma pesquisa em ensino de física, mais específicamente em ensino de acústica. Foi aplicada uma sequência didática em uma turma de primeiro ano do ensino médio, contextualizando os conceitos de acústica na audição de música e na vivência com a poluição sonora e utilizando como marco teórico a teoria da aprendizagem significativa desenvolvida por Ausubel. O objetivo foi aplicar a sequência didática para obter dados relativos à aprendizagem dos conceitos, analisando se foram, ou não, facilitadores significativos. Utilizou-se a gravação de áudio das aulas e um questionário, aplicado no início e no fim da sequência, para que se possa analisar o antes e depois, além do diário de campo, registrado pelo autor. A sequência foi composta por seis aulas de quarenta e cinco minútos. A análise dos dados obtidos aponta para uma facilitação da aprendizagem significativa de Acústica. Entretanto, seria importante dar continuidade à aplicação dos instrumentos de coleta de dados a um público mais numeroso e com perfis de turmas mais diversificados, para que os resultados propiciem resultados mais conclusivos e abrangentes. / The present work consists of a research in physics teaching, more specifically in acoustic teaching. A didactic sequence was applied in a first year high school class, contextualizing the concepts of acoustics in listening to music and living with noise pollution and using as theoretical framework the theory of meaningful learning developed by Ausubel. The objective was to apply the didactic sequence to obtain data regarding the learning of the concepts, analyzing whether or not they were significant facilitators. The audio recording of the classes and a questionnaire, applied at the beginning and at the end of the sequence, were used to analyze the before and after, besides the field diary, recorded by the author. The sequence consisted of six forty-five minute classes. The analysis of the data points to a facilitation of the significant learning of Acoustics. However, it would be important to continue the application of the data collection instruments to a larger audience and with more diverse class profiles, so that the results can lead to more conclusive and comprehensive results.

Les océans sont remplis de sons naturels et sont aujourd’hui de plus en plus envahis par des bruits d'origine humaine (bruits anthropiques). Ce mémoire étaye l’état actuel des connaissances sur les différentes sources de bruits sous-marins et leurs effets négatifs pour les espèces marines, les écosytèmes et les populations côtieres. Bien que le bruit soit un facteur de stress environnemental similaire à d'autres formes de pollution, la gestion du bruit anthropique a été négligée par les États et par le droit international. Cette étude met en lumière les difficultés pour le droit international et les États d’adopter des instruments spécialisés pour contrer le bruit anthropique alors que planent plusieurs incertitudes scientifiques. Le mémoire identifie et analyse les instruments contraignants et de soft law actuellement en vigueur, à l’international et au Canada, pour découvrir s’ils peuvent être mobilisés dans la lutte contre la pollution sonore dans les eaux arctiques canadiennes. L’adoption d’instruments juridiques ciblant spécifiquement les bruits anthropiques sous-marins est prônée mais avec la mise en garde que ce processus nécessitera une coopération inter et intra sectorielle concertée aux niveaux national, régional et international entre les milieux législatifs, scientifiques et décisionnels. / The world oceans are filled with natural sounds, which are being increasingly encroached upon by human sourced noises (anthropogenic noise). This thesis provides an overview of the current state of knowledge on the different sources of underwater noise and their negative effects on marine species, ecosystems and coastal populations. While anthropogenic noise is an environmental stressor similar to other forms of pollution, the management of anthropogenic noise has been neglected by States and by international law. This study highlights how scientific uncertainties and gaps complicate the process of crafting specialized international and domestic instruments to mitigate the impacts of underwater anthropogenic noise. The thesis identifies and analyzes binding and soft law instruments currently in force, internationally and in Canada, to discover whether they can be used to reduce noise pollution in Canadian Arctic waters. The adoption of legal instruments specifically applicable to anthropogenic underwater noise is advocated but with the caveat that it will require concerted inter and intra sectoral cooperation at the national, regional and international levels between legislative, scientific and decision-making circles.

Noise pollution is a big health hazard for people living in urban areas, and its effects on humans is a growing field of research. One of the major contributors to urban noise pollution is the noise generated by traffic. Noise simulations can be made in order to build noise maps used for noise management action plans, but in order to test their accuracy real measurements needs to be done, in this case in the form of noise measurements taken adjacent to a road. The aim of this project is to test machine learning based methods in order to develop a robust way of detecting and classifying vehicle noise in sparse traffic conditions. The primary focus is to detect traffic noise events, and the secondary focus is to classify what kind of vehicle is producing the noise. The data used in this project comes from sensors installed on a testbed at a street in southern Stockholm. The sensors include a microphone that is continuously measuring the local noise environment, a radar that detects each time a vehicle is passing by, and a camera that also detects a vehicle by capturing its license plate. Only sparse traffic noises are considered for this thesis, as such the audio recordings used are those where the radar has only detected one vehicle in a 40 second window. This makes the data gathered weakly labeled. The resulting detection method is a two-step process: First, the unsupervised learning method k-means is implemented for the generation of strong labels. Second, the supervised learning method random forest or support vector machine uses the strong labels in order to classify audio features. The detection system of sparse traffic noise achieved satisfactory results. However, the unsupervised vehicle classification method produced inadequate results and the clustering could not differentiate different vehicle classes based on the noise data. / Buller är en stor hälsorisk för människor som bor i stadsområden, och dess effekter på människor är ett växande forskningsfält. En av de största bidragen till stadsbuller är oljud som genereras av trafiken. Man kan utföra simuleringar i syfte att skapa bullerkartor som kan användas till planer för att minska dessa ljud. För att testa deras noggrannhet måste verkliga mätningar tas, i detta fall i formen av ljudmätningar tagna intill en väg. Syftet med detta projekt är att testa maskininlärningsmetoder för att utveckla ett robust sätt att detektera och klassificera fordonsljud i glesa trafikförhållanden. Primärt fokus ligger på att detektera bullerhändelser från trafiken, och sekundärt fokus är att försöka klassificera vilken typ av fordon som producerade ljudet. Datan som används i detta projekt kommer från sensorer installerade på en testbädd på en gata i södra Stockholm. Sensorerna inkluderar en mikrofon som kontinuerligt mäter den lokala ljudmiljön, en radar som detekterar varje gång ett fordon passerar, och en kamera som också detekterar ett fordon genom att ta bild på dess registreringsskylt. Endast ljud från gles trafik kommer att beaktas och användas i detta arbete, och därför används bara de ljudinspelningar där radarn har upptäckt ett enskilt fordon under ett 40 sekunders intervall. Detta gör att den insamlade datan har svaga etiketter. Den resulterande detekteringsmetoden är en tvåstegsprocess: För det första används den oövervakade inlärningsmetoden k-means för att generera starka etiketter. För det andra används de starka etiketterna av den övervakade inlärningsmetoden slumpmässig beslutsskog eller stödvektormaskin i syfte att klassificera ljudegenskaper. Detekteringssystemet av glest trafikljud uppnådde tillfredsställande resultat. Däremot producerade den oövervakade klassificeringsmetoden för fordonsljud otillräckliga resultat, och klustringen kunde inte urskilja mellan olika fordonsklasser baserat på ljuddatan.

[ES] La contaminación acústica se ha convertido en una causa de importantes problemas de salud, como alteraciones del sueño, cardiovasculares o cognitivas. En áreas urbanas, los altos valores del ruido debido al transporte y a otras actividades humanas pueden ser especialmente dañinos. Se trata de un tema de estudio abierto, debido a la amplia naturaleza del ruido y su gama de posibles fuentes (y, por lo tanto, las posibles soluciones para paliar cada una de ellas). Esta tesis se centra en la minimización del (i) ruido del sistema de escape, que puede abordarse mediante el uso de silenciadores (que a su vez tienen otras aplicaciones, como en los sistemas HVAC, es decir, calefacción, ventilación y aire acondicionado), así como del (ii) ruido y las vibraciones generales causados por el transporte, como por ejemplo el ruido de rodadura de los ferrocarriles, y el uso de barreras acústicas para mitigarlo. Por un lado, los silenciadores (que se pueden dividir en configuraciones reactivas, disipativas e híbridas) fueron adoptados hace tiempo en la línea de escape, pero también se ha extendido el uso de convertidores catalíticos y filtros de partículas diésel, los cuales, si bien su uso responde a razones medioambientales más que de reducción del ruido, tienen un impacto en el rendimiento acústico del sistema de escape. En este punto, se revisan diversas técnicas para la simulación numérica de la propagación del sonido dentro de conductos y demás dispositivos mencionados, y se proponen varios esquemas de optimización para la minimización de la transmisión del ruido. Esto incluye (i) la optimización dimensional de los silenciadores (incluidas las cámaras reactivas y disipativas), (ii) la optimización topológica del material disipativo (su distribución de densidad) dentro de la cámara disipativa y (iii) la optimización dimensional de los dispositivos de postratamiento de escape (convertidores catalíticos y filtros de partículas diésel). Por otro lado, el apantallamiento acústico tiene una amplia gama de aplicaciones, como las barreras acústicas de tráfico, carenados de ruedas de trenes o incluso revestimientos de conductos HVAC. En este punto, se requiere acoplar los problemas acústico y elástico en el contorno aire-estructura para obtener el problema vibroacústico. Aquí se plantea una formulación híbrida en desplazamiento-presión y se aplica a varios casos prácticos, con el fin de obtener diseños elásticos acústicamente optimizados. / [CA] La contaminació acústica s'ha convertit en una causa d'importants problemes de salut, com ara alteracions del son, cardiovasculars o cognitives. En àrees urbanes, els alts valors del soroll degut al transport i a altres activitats humanes poden ser especialment nocius. Es tracta d'un tema d'estudi obert, a causa de l'àmplia naturalesa del soroll i la gamma de possibles fonts (i, per tant, les possibles solucions per pal·liar cadascuna). Aquesta tesi se centra en la minimització del (i) soroll del sistema d'escapament, que es pot abordar mitjançant l'ús de silenciadors (que alhora tenen altres aplicacions, com en els sistemes HVAC, és a dir, calefacció, ventilació i aire condicionat), així com del (ii) soroll i les vibracions generals causats pel transport, com ara el soroll de rodament dels ferrocarrils, i l'ús de barreres acústiques per mitigar-lo. D'una banda, els silenciadors (que es poden dividir en configuracions reactives, dissipatives i híbrides) van ser adoptats fa temps a la línia d'escapament, però també s'ha estès l'ús de convertidors catalítics i filtres de partícules dièsel, els quals, si bé el seu ús respon a raons mediambientals més que de reducció del soroll, tenen un impacte en el rendiment acústic del sistema d'escapament. En aquest punt, es revisen diverses tècniques per a la simulació numèrica de la propagació del so dins de conductes i altres dispositius esmentats, i es proposen diversos esquemes d'optimització per minimitzar la transmissió del soroll. Això inclou (i) l'optimització dimensional dels silenciadors (incloses les càmeres reactives i dissipatives), (ii) l'optimització topològica del material disipatiu (la distribució de densitat) dins de la càmera disipativa i (iii) l'optimització dimensional dels dispositius de posttractament d'escapament (convertidors catalítics i filtres de partícules dièsel). D'altra banda, l'apantallament acústic té una àmplia gamma d'aplicacions, com ara les barreres acústiques de trànsit, carenats de rodes de trens o fins i tot revestiments de conductes HVAC. En aquest punt, cal acoblar els problemes acústic i elàstic al contorn aire-estructura per obtenir el problema vibroacústic. Aquí es planteja una formulació híbrida en desplaçament-pressió i s'aplica a diversos casos pràctics per obtenir dissenys elàstics acústicament optimitzats. / [EN] Noise pollution has become a cause of major health problems, such as sleep, cardiovascular or cognitive alterations. In urban areas, the high values of transport and other human-activity-related noise can be especially harmful. This issue is a large subject of study, due to the broad nature of noise and its range of possible sources (and therefore the potential solutions to alleviate each of them). This Thesis focuses on the minimization of (i) exhaust system noise, which can be addressed by the use of mufflers (which in turn have other applications, such as in HVAC systems, i.e., heating, ventilation, and air conditioning), and (ii) general noise and vibration caused by transport, such as railway rolling noise, and the use of sound barriers to alleviate it. On the one hand, mufflers (which can be divided into reactive, dissipative, and hybrid configurations) were long ago adopted in the exhaust line, but also the use of catalytic converters and diesel particulate filters has become spread, and, while their use responds to environmental rather than noise reduction reasons, they have an impact in the acoustic performance of the exhaust system. Diverse techniques for the modelling of sound propagation within ducts and the other aforementioned devices are reviewed, and several optimization schemes are proposed for the minimization of noise transmission. This includes (i) the sizing optimization of mufflers (including reactive and dissipative chambers), (ii) the topology optimization of the dissipative material (its density layout) within the dissipative chamber, and (iii) the sizing optimization of exhaust aftertreatment devices (catalytic converters and diesel particulate filters). On the other hand, sound barriers have a wide range of applications, such as traffic noise barriers, train wheel fairings or even HVAC duct coatings. At this point, it is required to pair the acoustic and the elastic problems at the air-structure boundary to obtain the vibroacoustic problem. A hybrid displacement-pressure formulation is recalled here and applied to several case studies, in order to obtain acoustically-optimized elastic designs. / Ferrándiz Catalá, B. (2023). Development of topology optimization techniques for noise pollution minimization in acoustic and fluid-structure problems [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/197985