Michael Vorlaender

Michael Vorlaender
RWTH Aachen University · Institute for Hearing Technology and Acoustics

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About

535
Publications
137,802
Reads
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5,518
Citations
Citations since 2017
174 Research Items
2856 Citations
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500

Publications

Publications (535)
Conference Paper
Full-text available
This work presents the procedure to create a model of the iconic scenery at Copacabana in Rio de Janeiro, Brazil, for auralization-based noise assessment in virtual urban environments with the aid of photogrammetry. The proposed procedure, firstly, delivers a description of the investigated space and of the photographic data acquisition. Secondly,...
Conference Paper
Full-text available
Virtual reality offers attractive tools to assess the urban design and its consequences for the quality of life in cities, especially in complex acoustic scenarios. However, the evaluation with regard to the level of realism of such scenarios still is a challenge. In this study, individuals are assessing with their own words the realism of such ren...
Conference Paper
Full-text available
Spatial fluctuations of room acoustic quantities in auditoria cast doubt on the validity of measurement results: when the measurement position is uncertain, the variation of the sound field over space can be understood as an influence factor affecting the overall (combined) uncertainty. This study presents a discussion consistent with the "Guide to...
Conference Paper
Ultrasonic Metal Welding is a friction welding process that relies on transmitting horizontal vibrations from a piezoelectric transducer to the workpieces that should be welded. The last part of this transmission chain, and the main component that transmits vibrations to the workpieces, is the horn. Although widely used, ultrasonic metal welding st...
Poster
Full-text available
This poster presents the IHTApark lab, a real environment monitorized with acoustic and visual recordings, as well as with weather indicators, together with a virtual reproduction of the same environment for real-time, realistic and physically-based renderings of such scenarios. The description in detail of how the virtual model has been designed a...
Conference Paper
Full-text available
This work presents the design and implementation of a perceptionally plausible vehicle pass-by noise synthesis model for environmental noise auralization. The source model consists of two separate components for engine noise and road-tyre noise synthesis. Additionally, the model accounts for spatial radiation characteristics by including higher-ord...
Conference Paper
When auralizing scenarios in the context of environmental noise, the simulation of sound propagation is an important aspect. Typically, the respective simulation models base on the concept of geometrical acoustics which enables processing a huge number of simulations even for complex scenes and higher frequencies in a reasonable time. However, the...
Article
No PDF available ABSTRACT Recent comparisons of room-acoustic simulations and auralizations demonstrated that a high degree of realism can be achieved under certain conditions. How close the simulation can get to reality depends on the definition of the objective in general terms (authenticity or plausibility). The question is also what is the appl...
Conference Paper
Full-text available
Automated capturing of room models for acoustic simulation might reduce time when acquiring room geometries for acoustic simulations. Additionally, ecologically valid representations of rooms in terms of both modalities, audio and visuals, are required for a qualitative evaluation of sound in architectural contexts. Those requirements might be achi...
Preprint
p>Analysis of sound source directivity uncertainty for room acoustics simulations and auralizations. </p
Preprint
p>Analysis of sound source directivity uncertainty for room acoustics simulations and auralizations. </p
Article
The ACOUCOU platform is a web-based, interactive, acoustics training platform that includes a set of free educational materials in various technical fields of acoustics. Educational materials are designed to serve as a modern self-development tool for students and engineers, as well as a comprehensive solution for professional education in the work...
Conference Paper
Full-text available
Auralization is a suitable method for the subjective evaluation of environmental noise. Due to its complexity, the plausible and immersive acoustic representation of outdoor scenarios in urban environments is an ongoing field of research. This work presents the design and implementation of a vehicle pass-by noise model with application in a spatial...
Article
Full-text available
In a recent publication, we presented an efficient method to find eigenrays in a stratified, moving medium. The simulation framework is designed to auralize aircraft flyovers. However, the method is restricted to the direct sound and a ground reflection. When dealing with flyover scenarios close to residential areas, the interaction of sound with u...
Conference Paper
Full-text available
Urban planners and architects present their designs as the fittest best solution for open public demands. However, yet there is a big void significant gap between the promises of designers and how the public space is perceived, especially when including urban sound features. Even at a low level of detail, the interest for what people judge in such...
Article
No PDF available ABSTRACT Measurements of random-incidence absorption coefficients have been hotly contested since the ASA was founded in 1929. Yes, you read correctly, since 1929! Theories, explanations, myths, and strange interpretations appear, disappear, and reappear over the decades. What is wrong with this method of measurement? This paper di...
Article
No PDF available ABSTRACT Bone conduction (BC) describes the transmission of vibrations via osseous, cartilage, and soft tissue pathways that contribute to the hearing sensation. It is important, e.g., in the context of BC hearing aids as well as for the occlusion effect and one’s own voice perception when using hearing protection or hearing device...
Conference Paper
Full-text available
The acoustic scattering of surfaces is crucial for acoustic simulations in rooms or urban spaces. The sound propagation is usually calculated by using geometrical simulation methods and random-incidence scattering coe ffi cients. In a running project, new approaches towards angle-dependent scattering metrics are defined and investigated. With this, it...
Conference Paper
Full-text available
Public spaces, such as parks, are an important part of urban design as they are source of recreation in daily life. Those spaces have a high impact on living comfort. This is why they are often subject to soundscape studies which are sometimes missing reproducibility. The auralization of virtual urban environments allows for controlled conditions i...
Conference Paper
Full-text available
Bone conduction (BC) describes the transmission of structural vibrations in the human head that lead to a hearing sensation. In this study, the focus is on the inertial and compressional component. These are based on the phenomenon that a wave propagating through the bone causes a basilar membrane displacement due to an inertial motion of the cochl...
Article
Full-text available
In the context of acoustic urban planning, the use of noise mappings is a worldwide well-established practice. Therefore, the noise levels in an urban environment are calculated based on models of the sound sources, models of the physical sound propagation effects and the position of the receivers in the area of interest. However, the noise mapping...
Conference Paper
Full-text available
A typical approach when simulating sound propagation in complex scenes is using the concept of geometrical acoustics. Every simulation framework is based on certain assumptions, which are limiting the scenarios they can be applied to. At DAGA 2021, we presented two frameworks. The Atmospheric Ray Tracing framework allows the simulation of curved so...
Article
Full-text available
Headphone transfer function (HpTF) and head-related transfer function (HRTF) measurements are crucial in acoustic science and in binaural virtual acoustic applications. Yet, their measurement set-up, procedure or post-processing is different for nearly every lab, especially for the HRTF measurements. To compare findings between different labs, thes...
Conference Paper
Transfer path analysis (TPA) and binaural transfer path synthesis (BTPS) are suitable methods to analyze and auralize combustion engine sounds at the driver's seat. In the context of vehicle sound design, the synthesized interior sounds can be assessed by metrics that are based on psychoacoustic parameters such as roughness, sharpness or loudness....
Conference Paper
Full-text available
Ultrasonic Metal Welding (USMW) is a welding process in which two thin metal ”workpieces” are welded together. The concept is simple: the workpieces - in our case, sheets of copper- are placed on the anvil, and compressed against each other by the sonotrode. The sonotrode then vibrates horizontally at 20 kHz, leading to friction at the interfaces b...
Conference Paper
Full-text available
Ultrasonic Metal Welding (USMW) is a friction welding process in which metal workpieces are welded together. The process is commonly used in the industry. However, even when given the same welding parameters, the strength of the weld can vary, and many factors can influence it. Currently, not enough is known about the welding process to be able to...
Article
No PDF available ABSTRACT The international acoustics community looks back with deep appreciation on the great lifetime achievement of David T. Blackstock. Always interested in international scientific exchange, he was especially involved in the International Commission for Acoustics (ICA) since the 1980s. Without his contributions to understanding...
Article
No PDF available ABSTRACT In 2016/2017, the first round robin on auralization in room acoustics was performed. This project allowed participants to contribute results of their simulation model for typical scenarios of sound propagation and room acoustics. The outcome of the round robin and details of the related scene database were published in two...
Book
Full-text available
Modellierung ist eine zentrale Fertigkeit, ein Modell ein Instrument, um beispielsweise Fragestellungen der physikalischen Akustik abzubilden, zu untersuchen und zu verstehen. Obwohl Modelle ganz unterschiedliche Fragestellungen in der physikalischen Akustik adressieren können, sind die zugrundeliegenden Modellierungsansätze und -philosophien häufi...
Article
The Reflections series takes a look back on historical articles from The Journal of the Acoustical Society of America that have had a significant impact on the science and practice of acoustics.
Conference Paper
Full-text available
Bone conduction (BC) describes the transmission of vibrations via osseous, cartilage and soft tissue pathways that contribute to the hearing sensation. The finite element method allows to simulate the three-dimensional wave propagation in complex geometries such as the human head, but it requires substantial simplifications due to the spatial discr...
Poster
Full-text available
[Received the DAGA 2021 Poster Award] Architectural and urban environments are exposed to a variety of judgements: from those who draw the plans to those actually using the space. Despite the diversity of perceivers of such environments, there is a lack of agreement on which reproducible methods can be used to evaluate architectural design and spa...
Article
Auralization is a suitable method for subjective noise evaluation of virtual prototypes. A basic requirement is the accurate modelling of the sound sources. This includes a dynamic and parametric description at multiple operating conditions. In the case of wave propagation including flow, such as aircraft or vehicle noise, aeroacoustics or fluid dy...
Poster
Full-text available
Listening experiments in virtual reality (VR) become more crucial during the last years. Therefore it is important that researcher have an easy possibility to design virtual listening experiments. In this work, a Framework is introduced where the user can design his own listening experiment without much background knowledge in VR. Due to its suppor...
Article
Full-text available
The presentation of architectural design in simulation environments demands strong 3D modeling abilities. Architects usually demonstrate presentation skills that mostly address researchers in the building simulation field. However, there is still a gap between the architect’s deliverable and the contextual scenario for overarching research purposes...
Article
Room acoustical simulations are usually evaluated by comparing them to measurements in corresponding physical environments as a benchmark. However, it proved to be challenging to provide a precise representation of the room geometry, the source and receiver characteristics, and the absorption and scattering coefficients to be re-modeled in the simu...
Article
This paper deals with the question of how specific weather conditions affect the perception of aircraft noise. Auralization is a suitable method by enabling parametrical decompositions of the overall aircraft noise scenario into source and propagation components. Considering influences on the auditory perception, the signal processing chain contain...
Article
Full-text available
Sound insulation auralization can be used as valuable tool to study the perceptual aspects of sound transmission in built environments for assessment of noise effects on people. It may help to further develop guidelines for building constructions. One advanced goal of real-time sound insulation auralization is to appropriately reproduce the conditi...
Article
Full-text available
The generalized cross-correlation with phase transform (GCC-PHAT) algorithm has proved to be useful for blindly estimating the direction of arrival of compact sound sources from microphone array recordings. In applications with distributions of partial sources, such as the tires of vehicles in urban environments, the GCC-PHAT needs to be improved,...
Conference Paper
Full-text available
Ultrasonic Sheet Metal welding (USMW) is often used in industry to join electro-technical components, such as in welding strands or battery components. The workpieces to be welded are compressed between two machine parts: the horn and the anvil. The horn vibrates at 20 kHz, causing friction between the two workpieces which leads to a friction-induc...
Article
Full-text available
Noise from traffic, industry and neighborhood is a prominent feature in urban environments. In these environments, sound reaches receiver points through reflections and diffractions. Real-time auralization of outdoor scenarios is a common goal for presenting sound characteristics in a realistic and intuitive fashion. Challenges in this attempt can...
Article
No PDF available ABSTRACT Multi-exponential energy decays—showing a distinct curvature in the measured decay curve—are a well known phenomenon in coupled spaces if both spaces exhibit different reverberation times due to their specific absorption characteristics or volumes. Recently, Berzborn et al. (2019) investigated directional energy decay curv...
Article
In this paper, the two-zone sound field reproduction problem is investigated with a newly proposed method. The aim of the two-zone reproduction problem is to achieve sound field reproduction in the bright zone while keeping the sound field energy in the dark zone as low as possible. The main difference between the proposed method and the convention...
Article
Full-text available
Generations of researchers observed a mismatch between headphone and loudspeaker presentation: the sound pressure level at the eardrum generated by a headphone has to be about 6 dB higher compared to the level created by a loudspeaker that elicits the same loudness. While it has been shown that this effect vanishes if the same waveforms are generat...
Conference Paper
Full-text available
Complex and resource intensive multi-physical models which integrate the domains of electrotechnical, structural dynamics and acoustics are needed to predict the noise, vibration and harshness (NVH) behavior of an electric passenger car drive train. Because of the highly limited resources in product development process of cars, engineers request ef...
Article
The analysis of the spatio-temporal features of sound fields is of great interest in the field of room acoustics, as they inevitably contribute to a listeners impression of the room. The perceived spaciousness is linked to lateral sound incidence during the early and late part of the impulse response which largely depends on the geometry of the roo...
Article
Full-text available
In this paper, an open-source framework for ray tracing in a stratified moving medium is introduced. This framework provides an efficient method to find eigen-rays connecting a source with a receiver and is designed for the purpose of aircraft noise auralization. The method is tested with respect to accuracy and run-time in an aircraft flyover scen...
Conference Paper
Full-text available
Over the last years, the idea of open science has become more and more popular. In this context, open-source software is an important aspect as it allows reproducing and comprehending scientific results in more depth. At the Institute for Hearing Technology and Acoustics in Aachen, the open-source C++ project ITAGeometricalAcoustics for the simulat...
Conference Paper
Measured room impulse responses are inherently uncertain like all measured quantities. This input uncertainty naturally propagates to derived metrics such as room acoustic single number quantities. Based on the framework provided by the Guide to the Expression of Uncertainty in Measurement (GUM), the example of the clarity parameter is taken to dis...
Presentation
Thanks to modern auralization methods, simulated aircraft flyovers can be experienced in virtual environments. Listening to such an auralization provides a more sophisticated impression of annoyance of aircraft noise in real scenarios than reading averaged sound pressure levels or noise maps. For proper auralization results, translation and refract...
Conference Paper
Generating natural embodied conversational agents within virtual spaces crucially depends on speech sounds and their directionality. In this work, we simulated directional filters to not only add directionality, but also directionally adapt each phoneme. We therefore mimic reality where changing mouth shapes have an influence on the directional pro...
Data
The Benchmark for Room Acoustical Simulation (BRAS) contains eleven acoustical scenes that are intended for the evaluation of room acoustical simulation software. This comprises simple scenes that isolate certain acoustic phenomena, as well as complex environments of different shape and size. Each scene consists of a scene description giving the ro...
Article
No PDF available ABSTRACT Human sound perception includes the ability to process auditory information from dynamic acoustic situations, which is an essential component for communication and orientation in everyday life. In contrast, standard psychoacoustic experiments don't include real-life situations.They include rather simple acoustic stimuli wi...
Chapter
Auralization of outdoor sound propagation models such as noise mapping is particularly challenging due to wave phenomena which can hardly be solved exactly following the wave equation. Therefore, diffraction and refraction require approximations which are adequate in terms of accuracy but still acceptable as concern computation times. Outdoor scena...
Chapter
In this chapter we will discuss the fundamental algorithms of geometrical acoustics, their variations of implementation in software and their efficiency. It will be shown that pure specular models (image models) are not capable of simulating room sound fields sufficiently accurate. But combinations of models of image sources and statistical models...
Chapter
As previous chapters dealt with virtual environments with sound in free-field and in enclosures (room acoustics, Sect. 11.7), situations with partition walls and complete buildings will be discussed in this chapter. This concerns the field of classical building acoustics as part of architectural acoustics. A typical example dealt with by building a...
Chapter
Auralization requires signal processing for merging the sound source signal with the sound propagation filter which was created by measurement or computer simulation. By adding the effects of the environment to the dry sound, we imprint the specific sound character the specific environment into the source. The classical mathematical tool to achieve...
Chapter
In the chapter on fundamentals in acoustics and for the discussion of plane waves, we concentrated on the sound field at arbitrary observation points. At this point, sound sources were not yet taken into consideration. The characterization of sound sources, however, is one of the most important tasks in simulation and auralization. Solving the wave...
Chapter
Virtual environments should be multimodal and interactive. The technology used for simulation and reproductions must take into consideration the aspect of several sensory inputs in real time and the interaction with the person who is embedded in the virtual environment. In order to achieve a real-time performance, specific runtime conditions must b...
Chapter
After getting familiar with the principle of auralization, i.e. the separation of the acoustic problem in a model of signal propagation and binaural synthesis or other spatial audio formats, and after having characterized the sources, we will now focus on the second key component of auralization. We consider the excitation signal as known and ready...
Chapter
Sound sources are the starting point when it comes to auralization. Their characterization includes the radiation properties such as power and directivity. And the sound signal, the temporal function of the generated sound, is the main input signal for auralization technology. Physical modelling, recording, and sound synthesis can be used for obtai...
Chapter
In this chapter, the acoustic model of airborne and impact sound transmission and the subsequent auralization technique are generalized towards other applications in acoustics and noise control engineering, particularly to vehicle acoustics. It was shown that the resulting sound pressure signal at the listener’s ears can be constructed by using bin...
Chapter
Virtual reality (VR) is a computer-generated environment for interaction in real time. One important feature of VR is the multimodality of the human-computer interface. Most VR systems were initially developed for 3D vision. In order to achieve the presence and immersion of the user, VR is not complete without the acoustic and haptic dimensions (an...
Chapter
The basics of sound wave radiation and propagation were discussed in the preceeding chapters. Free-field propagation can be studied and simulated with these mathematical models. Numerous problems, however, are related to sound in cavities. This is true for small appliances or vehicles as well as for larger volumes such as living rooms or kitchens,...
Chapter
The straightforward general extension of the propagation and auralization model is discussed now with regard to the excitation of solid structures by forces. The source, therefore, has to be characterized by its force output or by its velocity injected into the medium. With the velocity in the structure being known, transmission and radiation of so...
Chapter
Computer simulations of acoustic scenes are an important prerequisite for rendering. Technology for 3D sound reproduction, the so-called audio front-end or the acoustic human-machine interface, is an essential component of VR systems, which must be capable of fulfilling high-quality standards concerning the psychoacoustically relevant cues. These c...
Chapter
Acoustic waves are fascinating phenomena in gases, liquids or solids with numerous physical and technical aspects. Air is the medium of interest when it comes to audible sound. The gas dynamics of air determine the equations of the sound pressure and other field quantities from which the wave equation can be derived and solved for basic wave types....
Chapter
Signal theory provides the basis for coupling of computer simulation of sound sources and sound propagation. It is an important tool for bridging the gap between computer data and audible sound, which can be played through the soundcard of a PC, for example. Such tools are the classical digital audio processing components of sampling, analogue-digi...
Chapter
A proper physical foundation of acoustics is essential to understand the generation and transmission of sound. As far as simulation and auralization are concerned, however, human beings as the final recipient of sound are the final authorities on sound quality, comfort or annoyance. Basic knowledge about the human hearing system, its anatomy and ne...
Chapter
The field of structure-borne sound is more complex than fluid acoustics due to the manifold possible degrees of freedom for force and torque and corresponding elastic reactions. In contrast to fluids, solids can react with elastic forces to pure deformation. The number of possible waveforms is therefore higher. And these waveforms can interact and...
Chapter
Sound waves propagate from a source into the environment where they interact with objects. In indoor environments, sound is reflected and scattered at walls, floors, ceilings, and furniture. In outdoor environments, sound is scattered at trees, reflected at building façades or at the ground, or it may be diffracted around a noise barrier. Furthermo...
Article
With regard to the reduction of noise emitted by aircraft, there are approaches to reduce both the source power itself and the shielding of certain sound sources towards the ground. As dominant partial sound sources, countermeasures to jet and fan noise are particularly in focus. In this work, the impact of two promising approaches-chevron nozzles...
Conference Paper
Full-text available
In last decades the introduction of new building technologies and new powerful sound sources in and outside the dwellings, and the increased awareness of noise in the society have all contributed to the development of sound insulation designs. One important part of this development is the technical descriptions and solutions to various problems in...
Conference Paper
Full-text available
This study describes the effects of outdoor pass by noise sources, i.e. moving vehicle, on work performance under different sound insulation conditions of virtual built up building structures. The performance of buildings concerning protection against noise exposure is evaluated from technical and human-centred perspectives. The technical-oriented...
Chapter
Die physikalischen und perzeptiven Phänomene der Schallfelder in Räumen basieren auf den Abstrahlungseigenschaften der Schallquelle sowie auf Reflexionen und Streuungen, die sowohl mit Messungen als auch mit Simulationen gut erfasst und analysiert werden können. Die Ziele der raumakustischen Planung sind von der Anwendung des Raums abhängig. Bei ei...
Conference Paper
Full-text available
The impact of the architect's design on the acoustics of the environment is obvious. It becomes more specific when talking about room acoustics, building acoustics or soundscapes. However, the architecture pedagogic programs devote very little time to the study of acoustics. This work presents the results of an introduction course to research in ar...
Conference Paper
Full-text available
In a collaboration between architecture and engineering a test is conducted to see whether scale drawings made by architects purely listening to a virtual acoustic scene can be fitted to the simulation model by compensating an inherent, individual bias. A listening test regarding source distance perception and volume perception was conducted and mi...
Conference Paper
Full-text available
Sound localization experiments are common tests describing the individual perception of the spatial sound. However, 3-D audio auralization techniques include spatial scenarios more complex than those presented in the experiments. In those cases, a three-dimensional drawing of the aurally perceived space delivers detailed information about the indiv...
Conference Paper
Full-text available
With the goal of educational materials being available and accessible for everyone, adequate online course materials need to be prepared. For the field of acoustics, the ACOUCOU online platform (http://acoucou.org) was created in order to develop and offer free courses and materials using innovative teaching methods applying new technologies such a...
Conference Paper
Basierend auf dem Messaufbau und der verwendeten Messtechnik lässt sich die Unsicherheit einer Impulsantwort bestimmen. Der Einfluss dieser Unsicherheit kann bei der Berechnung raumakustischer Parameter Einfluss auf das Resultat nehmen. Am Beispiel des Klarheitsmaßes kann so die Fortpflanzung der Unsicherheit der Impulsantwort bis hin zu der Gesamt...
Conference Paper
Full-text available
The absorption coefficient estimation in a reverberation room according to ISO 354 implicitly assumes a diffuse sound field and a uniform damping of the room modes composing it. This requirement is violated when an absorbing specimen is mounted inside the room, resulting in decay curves with multi-exponential slopes. Based on an analytic model, Hun...
Conference Paper
Full-text available
Today’s wave-based acoustic simulation tools allow to simulate the lower frequency range of complex acoustic scenes, e.g. in small rooms such as car cabins. During their design process, it is of great interest to auralize these rooms. In order to get a spatial impression, binaural receivers can be included in the simulations. A straightforward app...
Article
Full-text available
Ultrasonic metal welding (USMW) is a common used manufacturing technology for cell, module or pack assembly of Lithium-ion battery systems of pouch type. Since every single joint can affect the efficiency and safety of the entire battery system, quality fluctuations of the joint are one of the greatest challenges. Despite its industrial spread in b...
Book
Auralization is the technique of creation and reproduction of sound on the basis of computer data. With this tool it is possible to predict the character of sound signals which are generated at the source and modified by reinforcement, propagation and transmission in systems such as rooms, buildings, vehicles or other technical devices. This book i...