Volker Hohmann

Study on the applicability of instrumental measures for black-box evaluation of static feedback control in hearing aids

Presented is a report on black-box evaluation of feedback control systems for commercial hearing aids. The aim of the study is to examine the ability of existing instrumental measures to quantify the performance of the feedback control system in black-box settings and on realistic signals, when more than one element of the signal processing chain may be active (compression, noise suppression, microphone directionality, etc.). The evaluation is carried out on 6 different hearing aids and for 10 measures. Thereby it is possible to see which measure is best suited to measuring which specific characteristic of the feedback control system, and serves as a beginning for conducting perceptual tests. The study uses static (but variable) feedback paths and is based on signals recorded from the in-ear microphone of an artificial head, on which the hearing instruments are mounted.

Towards Realistic Immersive Audiovisual Simulations for Hearing Research: Capture, Virtual Scenes and Reproduction

Most current hearing research laboratories and hearing aid evaluation setups are not sufficient to simulate real-life situations and to evaluate future generations of hearing aids that might include gaze information and brain signals. Thus, new methodologies and technologies might need to be implemented in hearing laboratories and clinics in order to generate audiovisual realistic testing environments. The aim of this work is to provide a comprehensive review of the current available approaches and future directions to create audiovisual realistic immersive simulations for hearing research. Additionally, we present the technologies and use cases of our laboratory, as well as the pros and cons of such technologies: From creating 3D virtual simulations with computer graphics and virtual acoustic simulations, to 360º videos and Ambisonic recordings.