Dissertations / Theses on the topic 'Sound engineers'

Smart tools for audio production have been making its way into modern audio production and is getting more popular in studio and postproduction work. In live sound however, there is few alternatives that exist. In this study live sound engineers experienced in live music sound reinforcement were interviewed about how they use gain and what considerations they make when adjusting gain. The aim of this study was to use their answers to create the foundation of a framework to an algorithm that can adjust gain automatically. The interviews were semi-structured, and the transcriptions were analysed using grounded theory. From the transcripts five categories were created and further divided into subcategories for deeper analysis. The study showed that the data in the study could not easily be proceduralized but instead two alternative ways of implementing this in practice, one that monitors the input signals and passes the information to the engineer. And another that adds a control layer to the monitoring where the parameter can be selected based on mixing strategy and the algorithms control can be switched on or off.

This project is a qualitative study which examines how best practice in multimedia learning can benefit learners using text-and-illustrations-based books. Drawing on data from six undergraduate audio engineering students, instructional design elements which are appropriate for the improvement of critical listening skills are put forward.

Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet AVB. Bandwidth utilisation and parameter groupings are among the factors which need to be considered in these designs. An implementation of an extensible, generic simulation framework would allow audio engineers to easily compare protocols and networking technologies and get near real time responses with regards to bandwidth utilisation. Our hypothesis is that an application-level capability can be developed which uses a network simulation framework to enable this process and enhances the audio engineer’s experience of designing and configuring a network. This thesis presents a new, extensible simulation framework which can be utilised to simulate professional audio networks. This framework is utilised to develop an application - AudioNetSim - based on the requirements of an audio engineer. The thesis describes the AudioNetSim models and implementations for Ethernet AVB, Firewire and the AES- 64 control protocol. AudioNetSim enables bandwidth usage determination for any network configuration and connection scenario and is used to compare Firewire and Ethernet AVB bandwidth utilisation. It also applies graph theory to the circular join problem and provides a solution to detect circular joins.

“How to engineer a mood - A study of sound in audiovisual contexts” is a study on the perception of sound in audiovisual contexts, i.e. sound and the image combined. There seems to be a consensus among researchers in the field on the fact that music influences the interpretation on film. However, there does not seem to be a specific consensus in regards to other sounds than music, such as the human voice or sound effects. Guided by a set of theories, an audiovisual text will be analyzed, in part through results of a quasi-experimental pilot survey and partly by the author herself. This paper would like to contribute in making the relationship of different sounds in conjunction with the image become slightly clearer. The outcome will help to show how a mood can be created with sounds. Although there is a limited number of theoretical models that have been developed in this field of research, the theories that are introduced will hopefully help to create a better understanding of sound in audiovisual texts.  Finally the theories and results will come together in this thesis; this will lead to an analysis and produce ideas for further research on how sound in audiovisual contexts influence our emotions. As mentioned before there has not been much research in this field, hopefully this thesis will be able to provide some clues and could serve as a first step for further research to find more definite answers on how emotions work in a audiovisual context. However, many questions will remain unanswered, and further research is needed to answer them.

Noise control and sound quality analysis are important, since noise has been registered to be a predominant factor in stress and a source of great annoyance. Traffic noise is a problem and a major part of this noise comes from heavy vehicles. The only legislative requirement for heavy-duty trucks regarding noise emissions, is that the noise level does not exceed an Aweighted sound pressure level of 80 dB. The specification of an A-weighted sound pressure level is, however, not an adequate description of psychoacoustic annoyance and therefore work towards defining a better description of loudness is one of the principal fields of acoustics today. Sound radiation from trucks is speed-related. At medium and high speeds, the overall noise level is comprised mainly of the tyre noise, whereas at low speed and during acceleration, exhaust noise and noise from the engine and transmission structure are predominant. In front of the truck, the noise from the engine and especially that from the timing transmission cover, the torsional damper and the oil sump, comprises a greater proportion of the total noise. The aim of sound quality analysis of diesel engines is to find cost-efficient methods of reducing sound radiation and of changing the character of the sound in order to minimise annoyance. This thesis concerns the development of experimental methods for analysing the sound quality of diesel engines, and focuses on measurement of acoustic intensity, multivariate data analysis, structural modification and subjective assessment of engine noise. The applicability of the FFT-based sound intensity method is evaluated. It is found that the intensity measurements may be influenced by high reactivity, interference due to partlycoherent sources, difficulties in performing the spatial average, real-time limitations and engine speed variations. Scanning the intensity probe, preferably by a robot, is necessary when measuring within narrow bands to avoid interference problems. Scanning achieves more reliable estimates of sound power and intensity vectors. Experimental design and the multivariate techniques, principal components analysis (PCA) and partial least squares (PLS) were utilised to facilitate interpretation of intensity measurements. The results show that PCA and PLS enable independent phenomena in the sound field to be extracted and which can thereby be visualised by principal spectra and principal radiating patterns. The characteristics of sound radiation are determined by designed experiments, sound intensity measurements and operational deflection shape estimations. These methods enable the effects on sound radiation of structure modifications to be predicted. An annoyance index for in-line 6-cylinder diesel engines in stationary running conditions was developed using multivariate statistics. The index is based on engine sounds resulting from structure modifications and changes in fuel. The annoyance level was measured during listening tests of sound stimuli recorded in stereo and reproduced by loudspeakers under anechoic conditions. The different sound stimuli were ranked using paired comparisons or the method of successive intervals. It was found that 94% of the variance of annoyance can be explained by a model based on loudness (Sone), sharpness (Acum) and harmonic ratio (rumble). Impulsiveness, roughness and tonality were other important criteria used in the study and which were found to have a relationship with specific speed ranges. The annoyance was minimised by an increase in stiffness in the lower part of the engine achieved by using a ladder frame in combination with a bearing beam.
Godkänd; 1996; 20061214 (biem)

The goal with this project, was to explore the producing of a musicvideo with a synergistic focus in a practical way. Beside the practical work with the recording and editing of music and video, I wanted to explore the sound engineers role in such a project? To my help I had the video producer Hannes Knutsson from the small film- collective Lefvande Bilder and the singer, guitarist and songwriter Conny Flink. The result of my work is a musicvideo published on the internet website YouTube and the report of the making of it along with my work around the question above is published in this report. The name of the recorded and filmed song, written and performed by Conny Flink is ”My Way”.

With the need for stealth in defense applications steadily increasing, noise reduction continues to play an important role in the world of aeronautics. With the ever increasing number of small UAV flight vehicle designs and their stringent weight requirements, acoustic solutions become progressively more complex. This thesis investigates the use of refractory foam, a new class of porous material, for designing effective silencers for small IC engines. The solution must be lightweight, compact, conformable, and capable of handling the rigors of flight. Throughout the course of this research, many silencer designs were fabricated to take advantage of refractory foam technology. These silencer designs were then tested against existing designs using both anechoic and outdoor testing techniques. These results proved refractory foam to be a superior broadband noise absorber that can survive harsh flight environment. Silencer designs using this material showed overall improvements in the areas of noise reduction, weight, size, and backpressure, compared to commercial designs. The final silencer design boasted an Aweighted overall sound pressure level that was 12.1 dBA lower than the reference case. This result was accomplished using nearly half the volume required by other designs to attain similar results.
Master of Science

A bass enhancement technique using the missing fundamental called VBS is presented. There are Several different approaches for using VBS in different applications. The technique is most useful in speakers that has a poor low frequency capability. It is presented in this report how it can be used for mixing purposes. How can a mix engineer use this technique to get a more balanced mix in laptop speakers without sacrificing the balance in large loudspeakers and headphones? To investigate this question an A/B style listening test is conducted, where the subjects get to answer both quantitative and qualitative questions. The answers are then analyzed using simple t-tests and categorizations of the qualitative information. The results of the test indicate that the mix with VBS is preferred in both the headphones and the laptop. There are no information indicating that the VBS has affected the mix in a poor or good way in the Loudspeakers.

Detta examensarbete är en förstudie där väl lyssningsanpassade rum har undersökts både objektivt och subjektivt med syftet att kunna identifiera och tolka allmänna akustiska fenomen som uppstår, och upplevs, samt upplysa läsaren om dessa. Rapporten behandlar ljudfysik så som akustik och våglära, ljudteknikerns roll, psykoakustik, kontrollrum och teknisk utrustning. De mätningar och lyssningstest som utförts har alla utgått ifrån den tänka lyssningspositionen som sedan ställts mot specifika krav och rekommendationer från AMS (Audio Measurement Standards) och EBU (European Brodcasting Union). Lyssningstesten har gjorts efter EBU-standard. Även intervjustudier har genomförts med erfarna ljudtekniker. I Slutsats och Diskussion jämförs objektiva mätdata med lyssningstest, där likheter och slutsatser om lyssningen dras.
This thesis is a preliminary study in which high quality listening environments have been investigated both objectively and subjectively with the purpose to identify and interpret general acoustic phenomenon that occurs, and how they are percieved, as well to enlighten the reader about these. The report deals with sound physics such as acoustics, an audio engineer's role, psychoacoustics, control rooms and technical equipment. The measurements and listening tests performed have all been done from the intended listening position which were then set against specific requirements and recommendations from AMS (Audio Measurement Standards) and EBU (European Broadcasting Union). Listening test have been made according to EBU standards. Also interviews were conducted with experienced audio engineers. In Conclusion and Discussion objectively measured data is compared with the listening tests, where similarities and conclusions about listening are drawn.

As music technology ever develops, so too the creative practices and sonic outcomes of popular music productions evolve in response. This project therefore investigates the ways in which user-led system design informs the author’s practice as a recording studio mix engineer and as co-creator of popular music recordings. The dissertation details a two-year study into the Stairways mixing preparation framework developed by the author. Stairways will be tested for its suitability to design personalised mixing systems with a view to achieving optimum creative results for various musical styles. The study documents the creation of mixes for eight original pieces of music, as written by six artists /bands, and where this development has been traced to provide a number of interpretations as 18 tracks on an accompanying CD portfolio. This compares the original artist ‘rough’ mixes with further insights into the application of digital and hybrid analogue systems. This project is situated within the field of professional practice and therefore draws upon a range of literature including scholarly texts, trade magazines, popular music press, practitioner interviews and weblogs. A mixed method research design employs the author’s multi-decade experience as a mix professional and educator via a practice-based approach to detail the processes involved in the creation of the original music in question. This is situated within three action research cycles that progress the design by detailing the insights gained from each recording session as they progress over time and where various emergent sonic and creative phenomenon are examined. The dissertation is supported by a detailed series of appendices to present technical approaches, reflective journal entries and philosophical considerations for how to approach a given mix.
Thesis (Masters)
Master of Music (MMus)
Queensland Conservatorium
Arts, Education and Law
Full Text

Describing planned acoustic design by single number ratings yields a weak link to the subjective event, especially when the single number ratings are interpreted by others than experienced acousticians. When developing infrastructure, tools for decision making needs to address visual and aural perception. Visual perception can be addressed using game engines and this has enabled the establishment of tools for visualizations of planned constructions in virtual reality. Audio engines accounting for sound propagation in the game engine environment are steadily developing and have recently been made available. The aim of this project is to simulate airborne sound insulation by extending the support of recently developed audio engines directed towards virtual reality applications. The case studied was airborne sound insulation between two adjacent rooms in a building, the sound transmitted to the receiving room through the building structure resulting from sound pressure exciting the structural elements in the adjacent source room into vibration. The receiving room composed modelled space in the game engine Unreal Engine and Steam Audio was the considered audio engine. Sound transmission was modelled by filtering based on calculations of transmission loss via direct and flanking paths using the model included in the standard EN 12354-1. It was verified that the filtering technique for modelling sound transmission reproduced attenuations in correspondence with the predicted transmission loss. Methodology was established to quantify the quality of the audio engine room acoustics simulations. A room acoustics simulation was evaluated by comparing the reverberation time derived from simulation with theoretical predictions and the simulated reverberation time showed fair agreement with Eyring’s formula above its frequency threshold. The quality of the simulation of airborne sound insulation was evaluated relating the sound field in simulation to insulation classification by the standardized level difference. The spectrum of the simulated standardized level difference was compared with the corresponding sound transmission calculation for a modelled scenario. The simulated data displayed noticeable deviations from the transmission calculation, caused by the audio engine room acoustics simulation. However, the simulated data exhibited cancellation of favourable and unfavourable deviations from the transmission calculation resulting in a mean difference across the spectrum below the just noticeable difference of about 1 dB. Single number ratings was compared and the simulated single number rating was within the standard deviation of how the transmission model calculates predictions for a corresponding practical scenario measured in situ. Thus, the simulated data shows potential and comparisons between simulated data, established room acoustics simulation software and in situ measurements should further be made to deduce whether the deviations entails defects in the airborne sound insulation prediction or is an error imposed by the audio engine room acoustics simulation.

The Reduction of engine noise, one of the primary noise sources in trucks and busses, is essential in order to fulfill various noise emission regulations such as ISO 362 [1]. At the same time, it is equally important to meet market demands in order to attract new customers while competing with other brands to lower overall noise levels. Sound power is a convenient descriptor of noise emissions when compared to sound pressure it is not dependent on the distance from the source and the surrounding environment. A number of standards for sound power measurement exist, requiring different methods, tools and environments. In engine development at Scania the sound power level is measured for different engine types for noise level determination and comparison purposes. Additionally, attempts to reduce noise through modifications of engine parts require many iterations in which sound pressures recorded at specific microphone positions are of primary interest. The necessity of running each engine at different speeds and load conditions with various modifications during development (combined with time restrictions) narrows down the choices to ISO 3745 which involves measuring sound power with stationary microphones. Despite ISO3745 apparent ease of use, prerequisites such as the number of microphones, the distance limitation of the microphones and free field conditions often pose a practical challenge. In Scania’s anechoic chamber it is impossible to meet these requirements due to limitations inherent to the room design such as size, poor absorption and limited space on the underside of the engine. This thesis comprises engine acoustic simulations in Nastran together with various measurements. Based on these, guidelines for power calculation have been developed taking into account the level of uncertainty and correction factors.

Denna studie undersöker hur musikproducenter och studiotekniker upplever sina olika roller i studioinspelningssammanhang. Detta utförs genom att studera studioteknikers och musikpro- ducenters skildringar av sig själva samt av vilka färdigheter som ingår i dessa olika roller. Studiens vetenskapsteoretiska ansats är kvalitativ, och bygger på ett hermeneutiskt perspektiv. Den metod som använts för att utföra insamlingen av data är semistrukturerade, kvalitativa intervjuer med tre personer som arbetar, eller har arbetat, som musikproducenter eller studio- tekniker. Ljudupptagningarna från intervjuerna har transkriberats, bearbetats och analyserats med hjälp av tematisk analys utifrån ett hermeneutiskt perspektiv. I resultatkapitlet klarläggs både informanternas syn på de olika rollerna samt deras uppfattning av att dessa roller ibland innehas av en och samma person. I studiens avslutande kapitel diskuteras dessa teman i relat- ion till studiens angivna bakgrundskapitel. Studien visar bland annat att informanterna, delvis tvärtemot den tidigare presenterade forskningen, anser att musikproducenter behöver ett stort mått musikteoretiska kunskaper för att kunna utföra sina uppgifter, att studiotekniker, förutom ljudtekniska kunskaper, även är i behov av konstnärliga kunskaper på ett djupare plan samt att många väljer att ta sig an rollen som både tekniker och producent på grund av ekonomiska och praktiska aspekter. Det fastställs även att gränserna mellan studiotekniker- och musikpro- ducentrollen i viss mån håller på att suddas ut.
This study aims to explore how music producers and recording engineers experience their different roles in a studio-recording context. This is done by examining recording engineer’s and music producer’s depictions of themselves and of the different sets of skills required within these roles. A hermeneutic perspective is the base for the scientific-theoretic approach of this qualitative study. The method for collecting data is semi structured, qualitative interviews and three persons identifying themselves as either music producer or recording engineer have been interviewed. The sound recordings from the interviews have been transcribed, processed and analyzed using thematic analysis and a hermeneutic approach. How both the informants’ perception of the different roles, as well as their understanding of these roles sometimes being held by one and the same person is being explained in the chapter result. The finishing chapter discusses these themes in relation to the previously given background. Among other things, the discussion chapter shows that the informants, partly opposite to what previously given research shows, thinks that music producers need theoretical knowledge in music to be able to carry out their tasks. It is highlighted that recording engineers, besides mastery of audio and technology, need to acquire a deeper level of artistic skills. It is also made clear that the lines between the recording engineer and the music producer are being erased, and that many people, due to economical and practical reasons, choose to take on the role as both music producer and recording engineer.

The search for quieter internal combustion engines drives the quest for a better understanding of the acoustic properties of engine duct components. Simulations are an important tool for enhanced understanding; they give insight into the flow-acoustic interaction in components where it is difficult to perform measurements. In this work the acoustics is obtained directly from a compressible Large Eddy Simulation (LES). With this method complex flow phenomena can be captured, as well as sound generation and acoustic scattering. The aim of the research is enhanced understanding of the acoustics of engine gas exchange components, such as the turbocharger compressor.In order to investigate methods appropriate for such studies, a simple constriction, in the form of an orifice plate, is considered. The flow through this geometry is expected to have several of the important characteristics that generate and scatter sound in more complex components, such as an unsteady shear layer, vortex generation, strong recirculation zones, pressure fluctuations at the plate, and at higher flow speeds shock waves. The sensitivity of the scattering to numerical parameters, and flow noise suppression methods, is investigated. The most efficient method for reducing noise in the result is averaging, both in time and space. Additionally, non-linear effects were found to appear when the amplitude of the acoustic velocity fluctuations became larger than around 1~\% of the mean velocity, in the orifice. The main goal of the thesis has been to enhance the understanding of the flow and acoustics of a thick orifice plate, with a jet Mach number of 0.4 to 1.2. Additionally, we evaluate different methods for analysis of the data, whereby better insight into the problem is gained. The scattering of incoming waves is compared to measurements with in general good agreement. Dynamic Mode Decomposition (DMD) is used in order to find significant frequencies in the flow and their corresponding flow structures, showing strong axisymmetric flow structures at frequencies where a tonal sound is generated and incoming waves are amplified.The main mechanisms for generating plane wave sound are identified as a fluctuating mass flow at the orifice openings and a fluctuating force at the plate sides, for subsonic jets. This study is to the author's knowledge the first numerical investigation concerning both sound generation and scattering, as well as coupling sound to a detailed study of the flow.With decomposition techniques a deeper insight into the flow is reached. It is shown that a feedback mechanism inside the orifice leads to the generation of strong coherent axisymmetric fluctuations, which in turn generate a tonal sound.

QC 20121113

Detta arbete syftar till att undersöka de relationer som uppstår mellan teaterrekvisita, skådespelare och ljudtekniker genom det posthumanistiska perspektivet agentiell realism. Jag utforskar även vilka fenomen som uppstår ur dessa relationer. Vad händer när sensorer implementeras i rekvisitan så att skådespelarna själva kan trigga vissa ljudeffekter från scenen?  För att undersöka detta har jag tagit fram prototyper av teaterrekvisita med sensorer och på så sätt i viss mening gett föremålen en egen röst. Detta bidrar till att de kan delta i dialogen med människorna i en föreställning, samtidigt som samspelet mellan skådespelare och ljudtekniker förändras.  Genom processens olika iterationer har gränsen mellan subjekt och objekt blivit allt mer otydlig, liksom den mellan de olika rollerna. Skådespelaren blir i viss mening ljudtekniker, liksom både rekvisitan och ljudteknikern i sin tur blir skådespelare.
This thesis aims to investigate the relationships between theatrical props, actors and sound engineers through the posthumanistic perspective of agential realism. I also explore the phenomena that emerge from these relationships. What happens when sensors are implemented in the prop in order for the actors themselves to trigger certain sound effects from the stage? To investigate this, I have developed prototypes of theater props with sensors and thus in some sense given the objects a voice of their own. This contributes to them participating in the dialogue with the people in a performance, while at the same time changing the interplay between actors and the sound engineer. Through the different iterations of the process, the division between subject and object has become increasingly unclear, just like the one between the different roles. In some sense, the actor becomes an audio engineer, as both the prop and the audio engineer in turn become actors.

Undersökningens syfte var att jämföra två implementationsmetoder för ljud i spel. Dessa metoder är en lagerbaserad metod och en förrenderad metod. I den lagerbaserade metoden kombineras de olika ljudlager som ljudeffekten består av i realtid av spelmotorn, där den individuellt för varje lager applicerar volym- och filtreringskurvor över distans. I den förrenderade metoden har dessa ljudlager redan i förväg kombinerats ihop i en enda audiofil, d.v.s. att den enda behandlingen som sker i ljudmotorn är att volymen sänks över distans, på hela ljudeffekten. I bakgrunden beskrivs övergripande teorier kring perceptionen av ljud över distans och olika lyssningssätt. Även den lagerbaserade ljudmotorn Sound-O-Matic (Double Trouble Audio, 2016) beskrivs kort. Frågeställningen utvärderades genom en prototyp och en nätenkät. Prototypen bestod av ett spel med de två implementationsmetoderna, uppdelade i två versioner: Version A = Förrenderad metod Version B = Lagerbaserad metod Respondenterna spelade båda versionerna av ljudimplementationen och skulle i vardera Version gissa på avståndet och riktningen av gevärsskott som avfyrades runt dem. Resultaten tyder på att den förrenderade metoden i Version A med fördel kan användas i spel, då majoriteten av respondenterna föredrog den före Version B.

Résumé:

Cette dissertation s’intéresse aux méthodes numériques dans le domaine de l’acoustique. Les propriétés acoustiques d’un produit sont devenues une part intégrante de la conception. En effet, de nos jours le bruit est perçu comme une nuisance par le consommateur et constitue un critère de vente. Il y a de plus des normes à respecter. Les méthodes numériques permettent de prédire la propagation sonore et constitue dès lors un outil de conception incontournable pour réduire le temps et les coûts de développement d’un produit.

Cette dissertation considère la propagation d’ondes acoustiques dans le domaine fréquentiel en tenant compte de la présence d’un écoulement. Nous pouvons citer comme application industrielle, le rayonnement d’une nacelle de réacteur d’avion. Le but de la thèse est de proposer une nouvelle méthode et démontrer ses performances par rapport aux méthodes actuellement utilisées (i.e. la méthode des éléments finis).

L’originalité du travail consiste à étendre la méthode de partition de l’unité polynomiale dans le cadre de la propagation acoustique convectée, pour des domaines extérieurs. La simulation acoustique dans des domaines de dimensions infinies est réalisée dans ce travail à l’aide d’un couplage entre éléments finis et éléments infinis.

La dissertation présente la formulation de la méthode pour des applications axisymétriques et tridimensionnelles et vérifie la méthode en comparant les résultats numériques obtenus avec des solutions analytiques pour des applications académiques (i.e. propagation dans un conduit, rayonnement d’un multipole, bruit émis par la vibration d’un piston rigide, etc.). Les performances de la méthode sont ensuite analysées. Des courbes de convergences illustrent à une fréquence donnée, la précision de la méthode en fonction du nombre d’inconnues. Tandis que des courbes de performances présentent le temps de calcul nécessaire pour obtenir une solution d’une précision donnée en fonction de la fréquence d’excitation. Ces études de performances montrent l’intérêt de la méthode présentée.

Le rayonnement d’un réacteur d’avion a été abordé dans le but de vérifier la méthode sur une application de type industriel. Les résultats illustrent la propagation pour une nacelle axisymétrique en tenant compte de l’écoulement et la présence de matériau absorbant dans la nacelle et compare les résultats obtenus avec la méthode proposée et ceux obtenus avec la méthode des éléments finis.

Les performances de la méthode de la partition de l’unité dans le cadre de la propagation convectée en domaines infinis sont présentées pour des applications académiques et de type industriel. Le travail effectué illustre l’intérêt d’utiliser des fonctions polynomiales d’ordre élevé ainsi que les avantages à enrichir l’approximation localement afin d’améliorer la solution sans devoir créer un maillage plus fin.

Summary:

Environmental considerations are important in the design of many engineering systems and components. In particular, the environmental impact of noise is important over a very broad range of engineering applications and is increasingly perceived and regulated as an issue of occupational safety or health, or more simply as a public nuisance. The acoustic quality is then considered as a criterion in the product design process. Numerical prediction techniques allow to simulate vibro-acoustic responses. The use of such techniques reduces the development time and cost.

This dissertation focuses on acoustic convected radiation in outer domains such as it is the case for turbofan radiation. In the current thesis the mapped infinite partition of unity method is implemented within a coupled finite and infinite element model. This method allows to enrich the approximation with polynomial functions.

We present axisymmetric and three-dimensional formulations, verify and analyse the performance of the method. The verification compares computed results with the proposed method and analytical solutions for academic applications (i.e. duct propagation, multipole radiation, noise radiated by a vibrating rigid piston, etc.) .Performance analyses are performed with convergence curves plotting, for a given frequency, the accuracy of the computed solution with respect to the number of degrees of freedom or with performance curves, plotting the CPU time required to solve the application within a given accuracy, with respect to the excitation frequency. These performance analyses illustrate the interest of the mapped infinite partition of unity method.

We compute the radiation of an axisymmetric turbofan (convected radiation and acoustic treatments). The aim is to verify the method on an industrial application. We illustrate the radiation and compare the mapped infinite partition of unity results with finite element computations.

The dissertation presents the mapped partition of unity method as a computationally efficient method and illustrates its performances for academic as well as industrial applications. We suggest to use the method with high order polynomials and take the advantage of the method which allows to locally enrich the approximation. This last point improves the accuracy of the solution and prevent from creating a finer mesh.

Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

Dans le cadre de la lutte pour la réduction des émissions de gaz à effet de serre, les biocarburants présentent un potentiel intéressant, en raison notamment de leur bilan CO2 "du puits à la roue" souvent très bon. Ainsi de nombreux programmes sont mis en œuvre, notamment en Europe, pour le développement de nouveaux carburants, et de moteurs automobiles adaptés à ces derniers. La conception de ces derniers nécessite une bonne maîtrise du système d’injection qui doit être aussi parfait que possible. Une meilleure connaissance du comportement et des propriétés sous haute pression de ces biocarburants revêt un caractère important. Le projet français NADIABIO rentre dans ce cadre et a pour principal objectif une meilleure maîtrise de l'injection (de la propagation d'onde dans la ligne HP à l'auto inflammation et la combustion) et de l'impact des biodiesels via une analyse fine à la fois numérique et expérimentale. En effet, dans le domaine des hautes pressions, la détermination des propriétés thermophysiques comme la densité ou les coefficients de compressibilité, présente souvent des difficultés contrairement à la vitesse du son qui peut se mesurer d’une manière simple et directe. Des dispositifs expérimentaux permettant d’effectuer des mesures de vitesses ultrasonores et de densité ont été mis au point pendant ce travail de thèse. Ils ont permis de fournir des données expérimentales de vitesses ultrasonores (pour des pressions et températures allant respectivement de 0,1 à 250 MPa et de 263,15 à 423,15K) et de densité (pour des pressions et températures allant respectivement de 0,1 - 100 MPa et de 283,15 à 393,15K). La campagne de mesure a été effectuée sur 12 biodiesels et sur un ensemble de 7 corps purs (EMHV, EEHV) représentatifs des mélanges étudiés. Cependant, pour des raisons de confidentialité, seuls les résultats relatifs aux corps purs et au Normafluid sont accessibles dans ce mémoire. Parallèlement, dans le but de proposer des méthodes de calcul prédictifs, nous nous somme intéressés à une procédure de type « predictor corrector », à une méthode de contribution de groupes moléculaires ainsi qu’à la théorie des états correspondants. Ces techniques de modélisation ont permis de déduire d’autres propriétés thermophysiques comme les coefficients de compressibilité, sous le même domaine de pression et de température
Within the politic changes for the reduction of greenhouse gas emissions, biofuels present an interesting potential because of their very well CO2 balance sheet. Numerous projects were engaged in Europe, for the development of new fuels and for the design of automobile engines adapted to these carburant. The conception of new engine requires specific systems of injection which must be perfectly designed. With this aim in mind thermophysical properties such as density and compressibility must be known with accuracy. The French project “NADIABIO” goes into this industrial issue and its main objective consist in a better control of the injection (wave distribution in the High Pressure line, during the automobile inflammation and combustion process) and the impact of biodiesels (FAME and synthetic materials) on the environment through fine numerical and experimental analyses. The direct measurement of the density or the coefficients of compressibility often presents difficulties under high pressure. It is therefore easier to determine it indirectly from the velocity of sound, which can be measured in a simple and direct way with a good accuracy. Therefore, experimental devices allowing to make measurements of ultrasound speeds and density were finalized during this work. Experimental data of ultrasound speeds (from 0,1 to 250 MPa and from 263,15 to 423,15 K) and of density (0,1 to 100 MPa and 283,15 to 403,15K) have been determined with good precision on 19 biodiesels (mixtures and synthetic products (FAME, FAEE)). However, for reasons of confidentiality, only the results relative to the synthetic products and to Normafluid appear in this report. At the same time, with the aim of proposing predictive methods, we are interested in the procedure like “predictor-corrector”, in the method contribution of molecular groups and to the theory of the corresponding states which allowed deducting the other thermophysical properties like the coefficients of compressibility as a function of temperature and pressure

Ett ljudfenomen som uppstår i samband med luftkomprimeringen i den nya D7 motorn har uppmärksammats som ett problem av kunderna. Ljudfenomenet som resonerar i hytten bidrar till en obehaglig arbetsmiljö. Uppdraget har i sin tur varit att utveckla en luftkompressormonterad ljuddämpare mot en kravspecifikation som eliminerar detta fenomen. Med hjälp av diverse verktyg och en spiral produktutvecklingsprocess utfördes ett flertal iterationer av dem koncept som kan tänkas lösa problemet. Dessa iterationer konstruerades i mjukvaran CATIA V5 för att sedan beställas in som fysiska prototyper i materialet Pa12. För att bekräfta prototypernas funktionalitet utfördes simuleringar samt fysiska tester. Det resulterande arbetet blev ett konceptförslag till Scania CV AB som uppfyller kravspecifikationerna. Lösningens ljuddämpningsförmågan reducerade ljudfenomenet med 73% i genomsnitt. Med hjälp av observationer och analyser under de fysiska testgenomförandet uppmärksammades komplikationer som bör åtgärdas. Det mest kritiska med det nuvarande konceptet är dem vibrationer som uppstår. För att åtgärda detta problem kommer det krävas ytterligare infästningspunkter på motsvarande sida till de nuvarande. All mätdata i denna rapport är modifierat. Detta för att skydda känslig information.
A noise phenomenon that arises in connection with air compression in the new D7 engine has been noted as a problem by the customers. The sound phenomenon resonates in the cabin contributes to an unpleasant work environment. The mission, in turn, has been to develop an air compressor-mounted silencer against a requirement specification to eliminate this phenomenon. Using various tools and a spiral product development process, a number of iterations were made of those concepts that could solve the problem. These iterations were engineered in the CATIA V5 software, then ordered as physical prototypes in the material Pa12. To confirm the prototypes' functionality, simulations and physical tests were performed. The resulting work became a concept proposal for Scania CV AB that meets the requirements specifications. The solution managed to reduce the sound phenomenon by 73% on average. With the help of observations and analyzes during the physical test implementation, complications were noted that should be addressed. The most critical on the current concept is the vibration that occurs. To fix this problem additional attachment points will be required on the corresponding side to the current ones. All data in this report have been modified. This is to protect sensitive information.

This dissertation ethnographically represents the work of three live sound engineers and the profession of live sound reinforcement engineering in the New York City metropolitan area. In addition to amplifying music to intelligible sound levels, these engineers also amplify music in ways that engage the sonic norms associated with the pertinent musical genres of jazz, rock and music theater. These sonic norms often overdetermine audience members' expectations for sound quality at concerts. In particular, these engineers also work to sonically and visually mask themselves and their equipment. Engineers use the term “transparency” to describe this mode of labor and the relative success of sound reproduction technologies. As a concept within the realm of sound reproduction technologies, transparency describes methods of reproducing sounds without coloring or obscuring the original quality. Transparency closely relates to “fidelity,” a concept that became prominent throughout the late nineteenth, twentieth, and twenty-first centuries to describe the success of sound reproduction equipment in making the quality of reproduced sound faithful to its original. The ethnography opens by framing the creative labor of live sound engineering through a process of “fidelity.” I argue that fidelity dynamically oscillates as struggle and satisfaction in live sound engineers’ theory of labor and resonates with their phenomenological encounters with sounds and social positions as laborers at concerts. In the first chapter, I describe my own live sound engineering at Jazzmobile in Harlem. The following chapter analyzes the freelance engineering of Randy Taber, who engineers rock and music theater concerts throughout New York City. The third chapter investigates Justin Rathbun’s engineering at Broadway’s Richard Rodgers theater production of “Porgy and Bess.” Much of engineering scholarship privileges the recording studio as the primary site of technological mediation in the production of music. However, this dissertation ethnographically asserts that similar politics and facilities of technological mediation shape live performances of music. In addition, I argue that the shifting temporal conditions of live music production reveal the dynamism of the sound engineers’ personhood on the shop floors of the live music stage.

Many structural acoustic and vibration designs rely extensively on materials that are light-weight, stiff, and highly damped. Advanced materials such as metallic foams can be engineered to achieve these properties in order to control sound and vibration for a variety of aerospace, maritime, and ground transportation applications. In this work, the structural and acoustic properties of commercially available and digitally designed metallic foams are analyzed through numerical and experimental methods. Furthermore as a post-manufacturing process, metallic foams can be engineered in order to preferentially alter the microstructure and achieve material property enhancements. In this work, the following engineering methods are proposed and investigated: plastic deformation and material saturation. When a metallic foam is plastically deformed, the foam's porosity and pore shape are dramatically altered. This transformation in microstructure can lead directly to changes in bulk properties. In this work, a method for triaxial hydrostatic compression of metallic foams is proposed and demonstrated experimentally. The structural properties of transformed foams are tested using a load cell with digital image correlation. Transformed foams exhibit higher compliance, higher toughness, and a reduced Poisson ratio. Measurement and analysis of acoustic properties indicate that the transformed foams can absorb significantly more sound than the conventional samples of equal thickness in the test range of 0.25 - 4.50 kHz. Due to their open-cell microstructure, metallic foams can be filled with saturating materials. In this work, metallic foams saturated with viscous liquids are investigated for reducing vibration transmissibility in a structure. For the best performing saturated foam subject to a transient excitation, an order of magnitude increase in damping ratio is measured. Additionally, a composite foam (consisting of metallic foam saturated with polyurethane foam) is fabricated to enhance acoustic properties. For the best performing composite foam at normal incidence, the sound absorption coefficient is improved by a factor of 6 near 0.60 kHz and by a factor of 2 up to 4.5 kHz. Lastly, two methods for estimating acoustic absorption in metallic foams are presented which utilize finite element analysis and boundary layer theory. The proposed methods are discussed for commercially available foams as well as for representative digital designs. Limitations and assumptions of the methods pertaining to size scales and boundary layer features are addressed.

碩士
銘傳大學
新媒體暨傳播管理學系碩士在職專班
105
Abstract With the advancement in technology and the various media for information available, the use of computers has become a common practice in the stage lighting and sound/video industry. Eventhough the youth of today has an increasingly solid foundation in technology and foreign languages, they lack the interest in this industry since it requires a large amount of manual labor. As a result, the industry is facing an aging problem among its engineers as well as a reduction in computer literacy. Therefore, one should focus on the importance of engineers. So, how does one find an engineer worth investing and managing long term? In the past, criteria for evaluation of engineers is often based on personal opinions and experiences. Needless to say, such method lacks objectivity. Using fuzzy theory, the current study aims to develop objective criteria of evaluation to be used in the stage lighting and sound/video industry. First, by utilizing literature review and interviewing conducted to managers within the industry, this study obtains 2 criteria and 9 sub-criteria for selecting candidates. Two criteria are potential and explicit, nine sub-criteria are active, resilience, attitude, problem, teamwork, service, coordination degree, professional knowledge, and professional competency. Pairwise comparison is used to determine the weight of the criteria. Scores are given to evaluate the importance of the sub-criteria and the satisfaction rating for candidate in regards to the sub-criteria. A comprehensive evaluation can then be obtained through the integration of all levels. Lastly, Chen’s ranking method is applied to determine the most suitable candidate. Keywords: personnel selection, engineer, stage lighting and sound/video industry, fuzzy multi-criteria decision making, competency.

This legal policy thesis asks: Is sampling so inconsistent with copyright that it warrants a unique system? Sampling is the musical practice of arranging new recordings from existing recordings. Often, it conflicts with copyright, a legal system that aims to encourage progress and innovation, primarily by granting exclusive rights as incentives to create and distribute original works. Two countervailing positions in existing literature articulate the conflict between sampling and copyright. The first views sampling as an appropriative practice that subverts copyright safeguards against unauthorised copying and adaptation. If this is true, then appropriation art cannot be reconciled with copyright law in any stable, lasting or meaningful manner. The second views copyright as an excessive restraint on creativity, a leash on artists. Scholars holding this position point to copyright's longstanding discrimination against sampling, evident from US copyright cases restricting 1990s hip-hop artists and admonishing one sampling artist with biblical commandment: 'Thou shalt not steal'. This thesis argues that sampling can align with the purpose of copyright to encourage progress and innovation. It shows how sampling is consistent with originality, the core concept that separates the copyright wheat from the unprotected chaff. Originality calls not for the conjuring of material from thin air, but rather the rearrangement of prior works, genres and conventions. By locating rearrangement at the heart of originality, we can see that sampling can contribute to the body of original works and therefore the purpose of copyright. In doing so, this thesis shows that sampling conflicts with the operation of copyright, as expressed in international treaty, national laws and industry conventions. While amending the operation of copyright is difficult, it is possible and indeed desirable to reform copyright to encourage rearrangement, not because it enables sampling, but because it promotes originality. Building on the concept that the rearrangement of past material is the foundation of originality, this thesis explains two potential policy responses to promote originality. Encouraging transformative use, as a conceptual foundation for fair use exceptions, can promote the rearrangement of existing original works into new original works. Likewise, ex post monitoring, as an alternative to ex ante licensing, can enable tolerated uses, incremental originality and distributed innovation at the scale of digital platforms.

A criação e disseminação da música é um dos fenómenos mais intrigantes da história da humanidade, e a gravação e impressão da mesma em formato físico na transição entre o século XIX e XX representa uma revolução, não só tecnológica, mas também cultural. Por trás das ondas sonoras emitidas pelo altifalante moderno, encontra-se mais do que apenas o músico e o compositor - revela-se o engenheiro de som, permitindo que dada obra chegue aos nossos ouvidos tal como a ouvimos num disco de vinil, CD ou cassete. Será (ou deverá) ser o papel do engenheiro de som apenas o de um simples catalisador técnico? Que impactos quantitativo e qualitativo tem o mesmo na obra final audível? E fará sentido categorizar tão estritamente os rótulos de “produtor”, “técnico” e “artista” num século XXI de revoluções tecnológicas? Esta tese e relatório de estágio procuram aprofundar estas questões, obtendo conclusões com base em experiências práticas e reais do dia-a-dia num estúdio de gravação profissional.
The creation and dissemination of music is one of the most intriguing phenomena in human history, and the recording and printing of music in physical format in the transition between the 19th and 20th centuries represents a revolution, not only technological but also cultural. Behind the sound waves emitted by the modern loudspeaker, there is more than just the musician and the composer - the sound engineer is revealed, allowing a given work to reach our ears as we hear it on a vinyl record, CD or cassette. Is (or should) it be the role of the sound engineer just that of a simple technical catalyst? What quantitative and qualitative impacts do they have on the final audible work? And does it make sense to categorize so strictly the labels of “producer”, “technician” and “artist” in a 21st century of technological revolutions? This thesis and internship report seek to deepen these issues, drawing conclusions based on practical and real-life experiences in a professional recording studio.

Desde o final da década de 1950, a edição fonográfica de música erudita em Portugal teve um grande desenvolvimento, ocupando um lugar relevante na nossa história da música. Nesse sentido, geraram-se mercados específicos, à imagem do que aconteceu no contexto internacional, entre os quais se destaca a produção discográfica de música antiga. O trabalho de investigação musicológica apresentado nesta tese ocupa-se desse contexto, o qual carece, até ao momento, de um tratamento historiográfico aprofundado, que este trabalho procura concretizar. O estudo da produção discográfica de música antiga em Portugal obriga a uma investigação alargada em três perspectivas: a indústria fonográfica de música erudita e os modelos de produção específicos; o movimento da música antiga em Portugal; a conjugação destas duas áreas, que é o principal campo de fundo desta investigação. Este trabalho procurou, pela primeira vez, realizar uma historiografia desse contexto de produção artística e editorial através da compilação das fontes discográficas comerciais, com repertório pré-romântico, produzidas em Portugal (a mais antiga surge em 1957) e do seu estudo aprofundado sob diferentes domínios: modelos de produção, dinâmicas editoriais, principais intervenientes e circulação de repertórios em gravação. A principal ferramenta que serve de pano de fundo para este estudo consiste numa base de dados que reúne toda a informação recolhida ao longo da investigação em torno das fontes discográficas - até 2015, ano em que teve início o processo de inventariação. O desenvolvimento de uma dinâmica de produção discográfica de música antiga em Portugal a partir da segunda metade do século XX estruturou-se em diferentes fases de evolução entre os anos de 1957 e 2015, condicionadas por factores de ordem política e social, formação de intérpretes e o desenvolvimento do movimento da música antiga em Portugal, bem como através de diferentes modelos de produção e edição. Neste último domínio, o mercado discográfico nacional estruturou-se através de dinâmicas próprias, locais (com editoras e etiquetas nacionais de diferente natureza), ao mesmo tempo que não se alheou ao panorama internacional, sobretudo com a implementação de representantes ou departamentos das majors internacionais. O estudo discológico e historiográfico destas fontes, na perspectiva da sua produção, permite conhecer de forma aprofundada diferentes gerações e tipologias de intérpretes que tomaram parte nesse contexto e a sua produtividade. Não menos relevante é a acção dos produtores e técnicos de som envolvidos neste contexto, com uma preponderância e impacte muito relevante para o desenvolvimento desse mesmo mercado de produção artística. Por outro lado, estas fontes traduzem dinâmicas da circulação de repertórios em diferentes momentos, mediante diferentes tipologias de intérpretes e abordagens performativas, ao mesmo tempo que se torna evidente uma grande ligação entre a investigação musicológica e o campo específico da edição discográfica de música antiga. A riqueza de informação reunida e as conclusões que resultam da análise e estudo levado a cabo ao longo desta investigação, permitem alargar o conhecimento em torno do contexto da música erudita em Portugal na segunda metade do século XX e início do XXI, de figuras preponderantes cujos contributos são menos conhecidos, dinâmicas relevantes da produção e prática musical de música antiga nesse período, bem como um legado de enorme valor material e imaterial para a nossa história da música.
Since the end of the 1950s, the phonographic edition of classical music in Portugal had a great development with a relevant place in music’s history of recent times. It generated specialized markets, as it also happened in the international context, among which stands out the record production of early music. The musicological research presented in this thesis focus in this context, which lacks a solid and deep historiographic study, which this work seeks to materialize. The study of early music record production in Portugal requires a broad research in three perspectives: the classical music industry and its specific models of production; the early music movement in Portugal; the combination of these two areas, which is the main field of this research. This study aims to carry out a historiography of this context of artistic and editorial production through the compilation of commercial recordings with pre-romantic repertoire produced in Portugal (the oldest was released in 1957) and its study under different fields: production models, editorial dynamics, key figures and the circulation of repertoire in recordings. The main tool for this analysis is a database that gathers together all the information collected during the research of the discographic sources - until 2015, the year in which the inventory process of the record sources began. The development of early music record production in Portugal in the second half of the twentieth century can be structured in different periods of evolution between the years 1957 and 2015, conditioned by political and social circumstances, by the development of specialized performers and the early music movement in Portugal, as well as through different models of production and publishing. In this last area, the Portuguese record market developed through its own dynamics, locally (with national companies and labels of different nature), at the same time that it maintained links with the international market, especially with the implementation of representatives or departments of the international majors in Portugal. From the perspective of record production, the discographic and historiographic study of these sources allows us to know different generations and profiles of performers who took part in this context and their productivity. No less relevant is the action of the producers and sound engineers involved, with a preponderance and very relevant impact for the development of that same market of artistic production. On the other hand, these sources translate dynamics about the circulation of repertoire at different moments, through different types of interpreters and performative approaches, while at the same time it becomes evident that there is a great connection between the musicological research and the specific field of early music production and edition. The richness of information gathered and the conclusions that result from the analysis and study carried throughout this research allow to widen the knowledge about the context of classical music in Portugal since the second half of the 20th century, as well as about preponderant figures whose contributions are less well known, relevant dynamics of the production and practice of early music in this period and a legacy of enormous material and immaterial value to our history of music.