This presentation summarizes the work I carried out during my 18-week internship at the Hearing Aid Business Unit of Shanghai United Imaging Microelectronics Technology Co., Ltd. My tasks included various standardized measurements such as electroacoustic testing according to GB/T and IEC standards, as well as directivity, reliability, and battery voltage testing. The main focus of […]
The internship at KARL STORZ SE & Co. KG contributed to the optimization of a hardware system used in electrosurgical applications. The project focused on improving power transmission efficiency and system reliability through experimental measurements and circuit simulations. Various diagnostic methods, including impedance analysis, infrared thermography, and high-frequency signal evaluation, were applied to identify and […]
This presentation details an internship conducted at the Kärcher Sound Lab focused on minimizing structure-borne noise. The central project involved the design, construction, and validation of a custom test rig for the dynamic characterization of viscoelastic damping elements. The resulting method allowed for measurement of frequency-dependent material properties and decoupling performance. The test rig was […]
Der Vortrag präsentiert die Ergebnisse eines Projekts zu den Zusammenhängen zwischen Sprachaudiometrie im Störgeräusch, Höranstrengung und auditiver Merkfähigkeit, an dem insgesamt n=65 hörgeschädigte Kinder und Jugendliche im Alter von 10 bis 17 Jahren teilgenommen haben. 42 der Kinder und Jugendlichen waren mit Hörgeräten versorgt, 22 mit Cochlea Implantaten, eine Person hatte keine Versorgung. Die Hörverluste […]
In its 2025 report on environmental noise in Europe, the European Environmental Agency stated that more than 30 % of the European population (about 150 Millionen Menschen) are exposed to long-term unhealthy noise levels from transport sources, such as road traffic, railways, and air traffic. Noise exposure has a greater health impact than better-known risks […]
This presentation will report on an acoustical engineering internship that was completed with and supervised by the American acoustical consulting and engineering company Brooks Acoustics Corporation (BAC) in Pompano Beach, Florida. Since 1992, the BAC team has contributed to over 1,100 national and international projects and actively participates in the academic, standards and professional communities […]
There are several standardized methods for characterizing the reflection properties of materials, such as the classic reverberation chamber method and the impedance tube method. For practical application, some alternative in-situ methods have been developed in recent years. However, all these methods to determine the reflection factor can lack robustness and reliability. In this report, a […]
During the internship at GoerTek Inc., the focus was primarily on the analysis and optimization of acoustic systems for “True Wireless Stereo Earbuds”, so-called TWS devices. The main responsibilities included conducting both subjective and objective tests based on acoustic performance, evaluating products through metrics such as frequency response curves, distortion curves, and manual listening tests. […]
High-channel-count spatial audio systems, such as Wave Field Synthesis (WFS), often rely on specialized hardware to drive the speakers. This significantly increases the costs. Furthermore, commercial audio equipment can be challenging to integrate with free and open-source software. To provide an open alternative, this thesis describes the design, implementation, and evaluation of an Ethernet audio […]
The combination of modern signal processing and loudspeaker development enables sound reproduction close to reality. Even though the loudspeaker system exhibits most distortions in terms of amplitude and phase response, those nonlinear responses are close to or even below the perceptual threshold. Yet, the audibility of group delay is still a topic of debate, although […]
Traffic noise pollution is responsible for major health issues. To predict the human traffic noise perception of urban soundscapes during the planning phase, a validated auralization tool is needed. The current approach by the IHTA is the auralization pipeline Pynamic, which is able to simulate heterogeneous sound paths containing both diffraction and reflection. This thesis […]
The balance between spectral resolution and physical accuracy is a central aspect for the design of real time path based auralization systems. The main problem is that reducing frequency resolution lowers processing costs but can significantly change the spectral representation of propagation effects. To investigate this, a systematic study of air attenuation, reflection and diffraction […]
Humans often miss otherwise obvious unexpected events when they are focused on a demanding task. This can occur in the auditory as well as visual domain – inattentional deafness and blindness, respectively. These phenomena can pose a danger in everyday life, such as not noticing a child crossing the street while focusing on other aspects […]
Geometrical acoustics has been widely used to simulate sound propagation in various environments because it has a lower computational cost than wave-based numerical simulations. An acoustic radiosity model (Sparrowpy) with a tabulated BRDF extension, which discretises reflections into finite cones based on random incidence or bidirectional scattering coefficients, is compared to an alternative ARE-based implementation […]
In urban acoustic environments, sound propagation is heavily influenced by obstacles that block the direct line-of-sight, making diffraction a crucial mechanism for plausible acoustic simulations. While the Uniform Theory of Diffraction (UTD) resolves the unnatural discontinuities present in standard Geometric Acoustics (GA), the computational cost increases exponentially with each additional diffraction order. This thesis investigates […]
Active Noise Cancellation (ANC) and Talk-Through (TT) modes are common features in modern headsets. ANC typically provides enough attenuation that background noise becomes difficult to characterise. In this internship, several warning signals, such as passing cars and shouted speech, were recorded and used as background noise, and multiple headsets with ANC and TT were evaluated […]
Im Rahmen des Praktikums wurde ein audio-basiertes Sensorsystem zur kontinuierlichen Überwachung respiratorischer Signale weiterentwickelt und für den produktiven Einsatz vorbereitet. Die Arbeit umfasste die Verbesserung einer Echtzeit-Signalverarbeitungspipeline, die Reduktion von Fehlalarmen unter realistischen akustischen Bedingungen sowie die Entwicklung robuster Machine-Learning-Modelle zur Hustenklassifikation. Besonderes Augenmerk lag auf der Datenqualität, der Generalisierungsfähigkeit gegenüber ungesehenen Nutzern sowie auf […]
The primary objective of this thesis was to model primary school classroom noises in acoustic virtual reality of the three activity-based acoustic situations (ABAS): silent work, group work, and classroom break. In a subsequent step, the objective was to evaluate how close these noises resemble real-life primary school classroom soundscapes. Currently, there is no freely […]
The occlusion effect (OE) describes the increased perception of body internal sound such as one’s own voice when the ear canal is blocked. This phenomenon often leads to discomfort with hearing aids or hearing protection devices. There are two common approaches for the assessment of the OE. The objective OE which is based on ear […]
Should we trust statistical equations for prediction of room acoustics? How much detail should a geometrical acoustic model have? How to predict the behavior of baffles? These are some of the questions that don’t have a definitive answer when it comes to computer models using geometrical acoustic methods. We will discuss several studies where we […]
