The measurement of the absorption coefficient in reverberation chambers according to the international standard ISO-354 shows a poor reproducibility between laboratories. One reason is the non-uniform distribution of absorption due to the placement of the test object. This causes shorter decay times for modes with oblique and perpendicular incidence on the absorber. Modes propagating parallel […]

Over the past few decades, research began to focus increasingly on the use of spherical microphone arrays to study the spatial properties of acoustic wave fields. To estimate the plane wave incidence accurately, the unwanted effects generated by the spherical microphone array itself in the recorded sound pressure should be eliminated by radial filtering. To […]

Bone conduction has a big impact on the perception of the human being. Even though headphones are used by a billion of people around the world, it was yet not analyzed if the headphones excite structure-borne sound. Structure-borne sound they could cause bone conduction or cartilage conduction and interfere with the perception of the user. […]

Progress in the field of computer-based calculation and simulation of sound fields and acoustic propagation effects enable numerous new applications for auralisation, e.g. design of cities and buildings, noise reduction and machine learning. In addition to the consideration of audible propagation effects a realistic synthesis of the source signal is essential for the generation of […]

Listening effort is defined as the use of cognitive resources necessary to complete a task or follow a conversation. The words heard must be consciously received in order to understand, processed and further communicate. Communication is an essential part of everyday social life and is usually connected with background noise. The aim of this work […]

In recent years, the use of virtual reality in research has greatly increased due to its ability to recreate complicated and realistic circumstances in a well-controlled laboratory environment. In this thesis the use of three different auditory cues in a auditory selective attention experiment in virtual reality is studied and validated, examining which of them […]

Over the last few years, virtual reality (VR) has emerged as a new technology that is allowing scientific research to investigate topics from another perspective. This is due to the possibility of creating more realistic scenarios in which all the variables are controlled. Thus, the conclusions taken from such research are more consistent since the […]

This paper describes the results of a subjective evaluation of classroom auralizations with different levels of detail(LOD) by a listening test. Computer Modeling of the classroom with different LOD and the auralizations are realized by using RAVEN, after which the listening test procedure and the analyzed results are presented. The task of listening test is […]

Conventional acoustic simulations are based on CAD models. The creation of the 3D model requires modeling expertise and time. Additionally, the variety of model strategies makes this process difficult to reproduce. In contrast, Photogrammetry techniques can economically achieve valid representations of rooms. However, the models created using Photogrammetry are aimed at visualization purposes. The models […]

Ultrasonic metal welding is a solid-state bonding process in which metal workpieces are exposed to high-frequency vibrations. It is an effective joining technology with a wide range of industrial applications with its unique advantages. The vibrations of mechanical parts in the machine cause fluctuations in the air pressure, thus causing sound waves to radiate. The […]

Ultrasonic Metal Welding (USMW) is a quite important welding technique, because of the relative low heat this welding process generate, it is used in numerous industrial applications. However, this welding technique have a disadvantage, the welding strength have large variance despite the same values of input machine parameters. Thus, to improve this welding technique more […]

The IHTA park is used as a case study for a lot of the institute´s research on auralisation and visualisation of urban scenes. An audio-visual model of the park already exists, which uses synthesised sounds for the dominant technical transportation sounds, while inserting recorded sounds as background sounds. Hence, a database of recorded background sounds […]

Die Hörbarmachung urbaner Lärmszenarien mittels Außenlärm-Auralisationen ist neben geeigneten Modellen zur Simulation von Schallausbreitung- und empfängern angewiesen auf Modelle von bewegten Quellen wie beispielsweise PKW. In dieser Arbeit wird die Unsicherheit der Quellparameterschätzung von Vorbeifahrtgeräuschen der Fahrzeuge untersucht. Dazu werden die realen Richtcharakteristiken des Mikrofons analysiert. Außerdem werden die Auswirkungen unsicherer Parameter bei der Berechnung […]

Auditory selective attention (ASA) is a common phenomenon which describes the ability to intentionally focus on a specific source of sound while ignoring other irrelevant sounds. Since in real life there are usually visual distractors in addition to auditory distractors, the effect of visual stimuli on ASA is also worth investigating. The purpose of this […]

In tropical countries, air conditioning systems are widely used to improve indoor climate. In many cases, natural ventilation can also provide thermal comfort for users with less energy consumption and better air quality as long as the pollution outdoors is not too high. However, openings in the facades for natural ventilation decrease the sound insulation. […]

The simulation of audio-visual performance is despite technological advancements still a challenging task which usually requires researchers to simplify problems in order to reduce computational complexity, sacrificing both auditory and visual fidelity. This raises the question as to what degree a model can be simplified without a noticable loss of quality. In order to analyze […]

Angetrieben durch die Reduzierung von Lärmbelastung und Simulation von Schallausbreitung kann akustische virtuelle Realität (AVR) zur Durchführung von Untersuchungen eingesetzt werden. Zunächst wird bildbasierte photogrammetrische Software verwendet, mit der ein städtisches Küstengebiet nachgebildet wird, um eine visuelle Darstellung der komplexen Umgebung zu generieren. Photogrammetrie erzeugt fotografische Punktwolken, die für immersive Anwendungen oder traditionelle Wiedergabemedien zu […]

The term irrelevant sound effect (ISE) refers to a significant reduction in the immediate serial recall of lists of presented items, usually digits or letters, when irrelevant auditory sound is presented together with the items to be memorized. This study aimed to investigate the impact of signal-to-noise ratio (SNR) and presentation modality on short-term memory […]

Für die möglichst präzise Auralisation von virtuellen Umgebungen ist die Kenntnis des genauen Schallfeldes der akustischen Szene notwendig. Einen Anteil zum diffusen Schall liefert dabei die Streuung an unebenen Oberflächen. In virtuellen Straßenumgebungen stellt daher die Streuung durch die Straßenoberfläche selbst einen möglichen Einfluss auf das Schallfeld dar. In der vorgestellten Arbeit werden die Schallstreuungseigenschaften […]

A previous study showed that background noises and background speech deteriorate children’s listening comprehension, as children lack the ability to neglect irrelevant sounds. A classroomlike atmosphere is required for an investigation of the effect of noise on listening comprehension. As a result, there is a possibility that certain uncontrollable elements will arise throughout the experiment. […]