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The bassoon is a conical woodwind instrument blown with a double-reed mouthpiece. The sound is generated by the periodic oscillation of the mouthpiece which excites the air column. The fundamental frequency of this oscillation is determined to a large extent by the resonances of the air column. These can be varied by opening or closing tone-holes. For any given tone hole setting a fine-tuning in pitch is necessary during playing. Musicians adjust the slit opening of the double-reed by pressing their lips against the opposing reed blades. These so-called embouchure corrections are required to tune the pitch, loudness and sound color of single notes. They may be tedious, especially if successive notes require inverse corrections. However, such corrections are essential: Due to the very high frequency sensitivity of the human ear playing in tune is the paramount requirement when playing music. This implies, that embouchure actions provide an important insight into a subjective quality assessment of reed wind instruments from the viewpoint of the musician: An instrument requiring only small corrections will be comfortable to play. Theoretical investigations of the whole system of resonator, reed, and musician by use of a physical model nowadays still seem insufficient with respect to the required precision. Therefore the path of well-described artificial mouth measurements has been chosen here. For the separate treatment of the resonator and the double-reed, existing classical models have been used. Modifications to these models are suggested and verified experimentally. The influence of the musician is incorporated by the lip force-dependent initial reed slit height. For this investigation a measurement setup has been built that allows precise adjustment of lip force during playing. With measurements of the artificial mouth parameters blowing pressure, mouthpiece pressure, volume-flow rate and axial lip position on reed, the experiment is fully described for a given resonator setting represented by an input impedance curve. By use of the suggested empirical model the adjustment parameters can be turned into model parameters. A large data set from blowing experiments covering the full tonal and dynamical range on five modern German bassoons of different make is given and interpreted. The experimental data presented with this work can be a basis for extending the knowledge and understanding of the interaction of instrument, mouthpiece and player. On the one hand, they provide an objective insight into tuning aspects of the studied bassoons. On the other hand the experiments define working points of the coupled system by means of quasi-static model parameters. These may be useful to validate dynamical physical models in further studies. The experimental data provide an important prerequisite for scientific proposals of optimizations of the bassoon and other reed wind instruments. It can further serve as a fundament for the interdisciplinary communication between musicians, musical instrument makers and scientists.:1 Introduction 1 1.1 Motivation 1 1.2 Scientific Approaches to Woodwind Musical Instruments 3 1.3 Organization of the Thesis 6 2 Acoustical Properties of the Bassoon Air Column 7 2.1 Wave propagation in tubes 7 2.1.1 Theory 7 2.1.2 Transmission Line Modeling 8 2.1.3 Implementation 18 2.1.4 Remarks on Modeling Wall Losses in a Conical Waveguide 19 2.2 Input Impedance Measurement 23 2.2.1 Principle 23 2.2.2 Device 23 2.2.3 Calibration and Correction 24 2.3 Comparison of Theory and Experiment 27 2.3.1 Repeatability and Measurement Uncertainty 27 2.3.2 Comparison of numerical and experimental Impedance Curves 32 2.4 Harmonicity Analysis of the Resonator 35 2.4.1 The Role of the Resonator 35 2.4.2 The reed equivalent Volume 35 2.4.3 Harmonicity Map 36 2.5 Summary 38 3 Characterization of the Double Reed Mouthpiece 41 3.1 Physical Model of the Double-Reed 41 3.1.1 Working Principle 41 3.1.2 Structural Mechanical Characteristics 42 3.1.3 Fluid Mechanical Characteristics 44 3.2 Measurement of Reed Parameters 49 3.2.1 Quasi-stationary Measurement 49 3.2.2 Dynamic Measurement 50 3.3 Construction of an Artificial Mouth 52 3.3.1 Requirements Profile 52 3.3.2 Generic Design 53 3.3.3 The artificial Lip 54 3.3.4 Air Supply 55 3.3.5 Sensors and Data Acquisition 57 3.3.6 Experimental setup 59 3.4 Summary 59 4 Modeling Realistic Embouchures with Reed Parameters 61 4.1 Reed Channel Geometry and Flow Characteristics 61 4.1.1 The Double-Reed as a Flow Duct 61 4.1.2 Bernoulli Flow-Model with Pressure Losses 65 4.1.3 Discussion of the Model 68 4.2 Quasi-static Interaction of Flow and Reed-Channel 72 4.2.1 Pressure-driven Deformation of the Duct Intake 72 4.2.2 Reed-Flow Model including Channel Deformation 75 4.2.3 Influence of Model Parameters 76 4.2.4 Experimental Verification 78 4.3 Effect of the Embouchure on the Reed-Flow 81 4.3.1 Adjustment of the Initial Slit Height 81 4.3.2 Quasi-static Flow in the Deformed Reed-Channel 83 4.3.3 Simplified empirical Model including a Lip Force 85 4.4 Summary 93 5 Survey of Performance Characteristics of the Modern German Bassoon 5.1 Experimental Procedure and Data Analysis 95 5.1.1 Description of the Experiment 95 5.1.2 Time Domain Analysis 97 5.1.3 Spectral Analysis – Period Synchronized Sampling 98 5.1.4 Spectral Centroid and Formants 99 5.1.5 Embouchure parameters 100 5.2 Observations on the Bassoon under Operating Conditions 105 5.2.1 Excitation Parameter Ranges 106 5.2.2 Characteristics of the radiated Sound 110 5.2.3 Reed Pressure Waveform Analysis 115 5.2.4 Summarizing Overview 118 5.3 Performance Control with the Embouchure 120 5.3.1 Register-dependent Embouchure Characteristics 120 5.3.2 Intonation Corrections 123 5.3.3 Sound Color Adjustments 127 5.3.4 Relation to the acoustical Properties of the Resonator 129 5.4 Summary 137 6 Conclusion 139 6.1 Summary 139 6.2 Outlook 141

Knochen und Muskel sind die wichtigsten Gewebe im muskuloskelettalen System welche dem Körper die Bewegungen möglich machen. Beide Gewebetypen sind hochgradig strukturierter Extrazellulärmatrix zugrundegelegt, welche die mechanischen und biologischen Funktionen bestimmen. In dieser Studie wurden die räumliche Verteilung der anisotropen elastischen Eigenschaften und der Gewebemineralisation im humanen kortikalen Femur untersucht mit akustischer Mikroskopie und Synchrotron-µCT. Die homogenisierten elastischen Eigenschaften wurden aus einer Kombination der Porosität und der Gewebeelastizitätsmatrix mit Hilfe eines asymptotischen Homogenisierungsmodells ermittelt. Der Einfluss der Gewebemineralisierung und der Strukturparameter auf die mikroskopischen und mesoskopischen elastischen Koeffizienten wurde unter Berücksichtigung der anatomischen Position des Femurschaftes untersucht. Es wurde ein Modell entwickelt, mit welchem der intramuskuläre Fettgehalt des porcinen musculus longissimus nichtinvasiv mittels quantitativem Ultraschall und dessen spektraler Analyze des Echosignals bestimmt werden kann. Muskelspezifische Parameter wie Dämpfung, spectral slope, midband fit, apparent integrated backscatter und cepstrale Paramter wurden aus den RF-Signalen extrahiert. Die Einflüsse der Muskelkomposition und Strukturparameter auf die spektralen Ultraschallparameter wurden untersucht. Die akustischer Parameter werden durch die Muskelfaserorientierung beeinflusst und weisen höhere Werte parallel zur Faserlängsrichtung als senkrecht zur Faserorientierung auf. Die in dieser Studie gewonnenen detaillierten und lokal bestimmten Knochendaten können möglicherweise als Eingabeparameter für numerische 3D FE-Simulationen. Darüber hinaus kann die Untersuchung von Veränderungen der lokalen Gewebeanisotropie neue Einsichten in Studien über Knochenumbildung geben. Diese auf Gewebeebene bestimmten Daten von Muskelgewebe können in numerischen Simulationen von akustischer Rückstreuung genutzt werden um diagnostische Methoden und Geräte zu verbessern. Bone and muscle are the most important tissues in the musculoskeletal system that gives the ability to move the body. Both tissues have the highly oriented underlying extracellular matrix structure for performing mechanical and biological functions. In this study, the spatial distribution of anisotropic elastic properties and tissue mineralization within a human femoral cortical bone shaft were investigated using scanning acoustic microscopy and synchrotron radiation µCT. The homogenized meoscopic elastic properties were determined by a combination of porosity and tissue elastic matrix using a asymptotic homogenization model. The impact on tissue mineralization and structural parameters of the microscopic and mesocopic elastic coefficients was analyzed with respect to the anatomical location of the femoral shaft. A model was developed to estimate intramuscular fat of porcine musculus longissimus non-invasively using a quantitative ultrasonic device by spectral analysis of ultrasonic echo signals. Muscle specific acoustic parameters, i.e. attenuation, spectral slope, midband fit, apparent integrated backscatter, and cepstral parameters were extracted from the measured RF echoes. The impact of muscle composition and structural properties on ultrasonic spectral parameters was analyzed. The ultrasound propagating parameters were affected by the muscle fiber orientation. The most dominant direction dependency was found for the attenuation. The detailed locally assessed bone data in this study may serve as a real-life input for numerical 3D FE simulation models. Moreover, the assessment of changes of local tissue anisotropy may provide new insights into the bone remodelling studies. The data provided at tissue level and investigated ultrasound backscattering from muscle tissue, can be used in numerical simulation FE models for acoustical backscattering from muscle for the further improvement of diagnostic methods and equipment.

Classical room acoustic simulation methods based on the principles of geometrical acoustics (GA) have nowadays become an accepted and highly developed tool for acoustic practitioners and researchers in predicting the acoustic characteristics of large rooms like concert halls, theatres or open-space offices. However, when it comes to small rooms, even the most advanced geometrically based methods appear to be flawed due to the inherent negligence of important low frequency wave effects, such as standing waves, diffraction and interference. In order to overcome this limitation the present thesis investigates the potential benefits of the application of the Finite Element Method (FEM) to the modally dominated part of the sound field. However, despite the fact that the FEM is a well-established tool in engineering sciences, which fully captures all relevant wave effects, its application to room acoustics introduces far-reaching and yet unresolved questions regarding the realistic source, boundary and receiver representation. The present thesis therefore establishes a complete framework for the combination of FE and GA-based room acoustic simulation results and discusses the inherent challenges and limitations including all aspects of sound generation, sound reflection and sound reception. Moreover, the thesis establishes detailed guidelines for the best-possible determination of all necessary input data for both simulation domains. The investigations conducted in the course of this thesis aim at two different goals. On the one hand the thesis investigates the influence of selected isolated aspects regarding their influence on the simulation accuracy. In particular, these topics include a study on the potential of the image source method to predict the modal characteristics of the low frequency Room Transfer Function (RTF), a study on the efficient modelling of porous absorbers in the FE domain and finally a study on the possible low frequency coupling of the excitation velocity of a loudspeaker to the sound field at the loudspeaker membrane. On the other hand the thesis investigates the overall potential of the presented combined approach by conducting extensive objective and subjective comparisons of measurement and simulation results for three types of acoustically relevant small spaces (a scale-model reverberation room, a recording studio and two different car passenger compartments). For each room considerable efforts have been made to obtain a best-possible a-priori assessment of all necessary material and source data for the simulations. However, especially with regard to the determination of the acoustic surface impedances at the room boundaries certain inevitable inaccuracies have to be accepted. While the presented results reveal an overall good agreement regarding the energy distribution in time and frequency domain for all considered rooms, the results clearly show that as expected the simulation accuracy considerably degrades with increasing complexity of the room geometry and boundary conditions. Moreover, it is important to mention that even with the FEM a precise prediction of the fine structure of the RTF appears impossible in the frequency range far above the Schroeder frequency. It can thus be concluded, that possible fields of application of the FE extension in room acoustic simulations lie in the prediction of the modally dominated low frequency part of the RTF of well defined rooms and in the prediction of sound fields that are strongly affected by near-field or diffraction effects as in the car passenger compartment. Thus, despite the general potential of the low frequency FE extension to realistically predict the modal structure of the low frequency part of the RTF, the Achilles’ heel of room acoustic FE simulations appears to be the determination of realistic impedance conditions on the room boundaries. Consequently the application of the finite element method to room acoustic applications calls for improved measurement techniques for the acoustic surface impedance.