Johannes Käsbach PhD project investigated the perception of apparent source width, which is an important subjective attribute describing the perceived spatial extent of a sound source in rooms. Specifically, he characterized apparent source width perception in normal-hearing, hearing-impaired and aided listeners as a function of physical stimulus parameters, such as the correlation between the two ear signals, the frequency content and the stimulus presentation level. Johannes developed a functional auditory model to predict the apparent source width across a wide range of acoustic conditions. The outcome of such a modeling framework can be useful to test and verify loudspeaker-based sound reproduction systems as well as hearing-aid algorithms.
During his defense, Johannes presented his main findings and successfully addressed all questions and comments raised by three examiners, namely Ewen MacDonald (Hearing Systems Group), Jürgen Tchorz (University of Applied Science, Lübeck, Germany) and William McAllister Whitmer (MRC Insitute of Hearing Research, UK).