Akustik-Blog

From 17^th to 19^th November 2023, the “junge DEGA Herbstworkshop” (autumn workshop) took place in Aachen. Junge DEGA is a section of the German Acoustical Society (DEGA) and partner of the Young Acousticians Network (YAN) of the European Acoustics Association (EAA). Its mission is to connect students, PhDs and young professionals in the domain of acoustics. The group organizes special sessions and panel discussions during the Annual German Conference on Acoustics (DAGA), providing information on research opportunities and job entry. Furthermore, junge DEGA offers a mentoring program with active participation from industry and academia.

The workshop started on Friday afternoon with a visit of HEAD Acoustics GmbH in Kohlscheid, where the participants got insights into the company’s research and development activities and experienced some hands-on demonstrations of new products. After this first visit, three RWTH spin-offs – FEV, KLANG, elevear – reported on their experiences in business practice and illustrated different career paths in the field of acoustics. The first day concluded with a meeting of the group resuming the year’s activities and discussing the plans for the upcoming conference DAGA 2024.

On Saturday, the participants visited four laboratories at RWTH Aachen University. The day started with a welcoming tour at the Institute for Hearing Technology and Acoustics (IHTA) with demonstrations of the room acoustics simulation software RAVEN, experiments for audio-visual perception studies and the SCaLAr loudspeaker array. The Institute for Automotive Engineering (ika) opened the doors to their semi-anechoic climate chamber and to a broad range of tire test rigs, which are used to determine the dynamic load during tire-road contact under the influence of different road surfaces. The Experimental Behavioral Psychobiology group & Brain Imaging Facility at RWTH University hospital presented research in which specific acoustic stimuli are used during magnetic resonance imaging to better understand the auditory processing with schizophrenia. Finally, the III. Physics Institute B presented its research on a sonar- and radar-equipped melting probe which aims to penetrate the ice shield and explore the subglacial ocean of the Jovian moon Europa (TRIPLE). Another project focused on the use of acoustic measurements to calibrate the neutrino observatory IceCube.

The weekend concluded with a hands-on workshop on binaural synthesis and virtual acoustics applications (see virtualacoustics.org) at IHTA.

Thanks to all participants and supporters!

Die Fachgruppe „junge DEGA“ der Deutschen Gesellschaft für Akustik e.V. (DEGA) veranstaltet regelmäßig einen Herbstworkshop mit dem Ziel, junge Akustikerinnen und Akustiker (Studierende, Promovierende, Young Professionals) zu vernetzen und persönlichen Austausch zu ermöglichen. Der diesjährige Herbstworkshop wird organisiert durch die aktuelle Leitung der Fachgruppe (Simon Kersten und Jonas Heck) mit Unterstützung weiterer Kolleg:innen des IHTA. Der Workshop findet vom 17.-19. November 2023 in Aachen statt.

Auf dem Programm des Herbstworkshops steht:

• Besuch des Instituts für Hörtechnik und Akustik (IHTA) an der RWTH Aachen, inkl. „Hands-On“-Workshop zur virtuellen Akustik
• Austausch zu Fach- & Promotionsthemen der Teilnehmenden
• Besuch weiterer Forschungseinrichtungen an der RWTH & Industriepartner
• Sitzung der junge DEGA-Fachgruppe

Anmeldung und Details zum Programm: https://www.dega-akustik.de/junge-dega/projekte (Anmeldeschluss: 31.10.2023).

jDEGA_Herbstworkshop_2023_Programm

Am 21. Januar 2022 hat Herr Ingo Witew seine mündliche Promotionsprüfung erfolgreich abgeschlossen.

Herr Witew promovierte über das Thema:

„Measurements in room acoustics – Uncertainties and influence of the measurement position“

Abstract:

Regardless of the field, measurements are essential for the validation of theories and for making well-founded decisions. A criterion for the validity and comparability of measured values is their uncertainty. The „Guide to the Expression of Uncertainty in Measurement“ (GUM) provides a standardized framework for determining and interpreting measurement uncertainty. In room acoustic measurements, the application of these rules is not yet widespread. On the one hand, this is due to the fact that well established 2-CH-FFT correlation techniques rely on a complex principle, which is not covered by the classical guide. In addition, the effect of input variables on a measurement can only be determined in individual cases after considerable effort. An example are fluctuations of room acoustic quantities over smallest distances between measurement locations in concert halls. This change of the sound field over the location is sometimes considerable and can only be predicted in relatively simple boundary value problems. This raises the question of the validity and interpretability of room acoustics measurements.

The goal of this thesis is to provide a GUM-compliant discussion of uncertainties in measuring room acoustic single-number quantities. This starts with a structured search of variables that potentially influence the measurement of room impulse responses. In a second step, this uncertainty is propagated through the algorithm for determining room acoustic single-number quantities.

Further emphasis is placed on the investigation of spatial fluctuations of the sound field in auditoria. The influence of an uncertain measurement position on the overall measurement uncertainty is discussed. To reach general conclusions, the relation between changes in the measurement location and the corresponding changes in room acoustics quantities is investigated empirically in extensive measurement series. To this purpose, a measurement apparatus was designed that allows automatic, high-resolution sampling of sound fields over large areas. The collected data sets the foundation to propagate the uncertainty using a Monte Carlo method.

This study shows how precisely a measurement position must be defined to ensure a given uncertainty of room acoustical single-number quantities. The presented methods form a foundation that can be flexibly extended in future investigations to include additional influences on the measurement uncertainty.

Das IHTA gratuliert sehr herzlich!!

Fotos: Josep Llorca-Bofí

Am 26. November 2021 hat Herr Florian Johannes Pausch seine mündliche Promotionsprüfung erfolgreich abgeschlossen.

Herr Pausch promovierte über das Thema: „Spatial audio reproduction for hearing aid research: System design, evaluation and application“

Abstract:

Listening, understanding and communicating are essential skills for social interaction in everyday life. Hearing loss (HL) may have severe consequences on these skills and affect individuals by hindering language development, learning success and participation in social life already at an early age. Depending on the individual predisposition, those affected are likely to withdraw from socialisation processes and sometimes suffer from compromised mental and general health. However, these consequences are not limited to children but also apply to adults and elderly people, especially those who refuse to acknowledge their HL and appropriate treatment, leading to an increased risk of apathy and depression, as well as memory problems and dementia. Assistive listening devices, such as hearing aids (HAs), represent an effective technical intervention tool capable of partially restoring impaired hearing and helping to overcome the aforementioned consequences of HL. Despite using the latest technology, individuals fitted with HAs often complain about poor performance of their devices, particularly in demanding indoor communication settings with unfavourable room acoustics. To some extent, these performance shortcomings can be attributed to limitations of HA algorithms, which are often designed and tested using simplified laboratory scenarios that may differ substantially from complex real-world situations. This thesis contributes to bridging this gap by exploring the advantages and flexibility of virtual acoustic environments (VAEs) reproduced by state-of-the-art spatial audio reproduction methods adapted for HA research. In order to further approach the overarching goal of ecological validity, the system design has been complemented by real-time implementations and room acoustic simulations, allowing to include listener movements via motion tracking and simulate plausible indoor environments, respectively. The systems are comparatively evaluated based on measurements and perceptual experiments with normal-hearing individuals, demonstrating their applicability in experiments involving normal-hearing participants and participants with HL.  

Doctoral exam Florian Pausch, Prüfungskommission: Zweitgutachterin Prof. Dr. Astrid van Wieringen (KU Leuven), Prof. Dr. Andrei Vescan, Prof. Dr. Dirk Uwe Sauer, Prof. Dr. Janina Fels

Doktorprüfung Florian Pausch. Prof. Dr.-Ing. Janina Fels und Dipl.-Ing. Florian Pausch. Foto: Mark Müller-Giebeler

Das IHTA gratuliert sehr herzlich!!