I did my Master’s Thesis at Applied Acoustics and was offered to continue with my work as a Ph.D student. I have a M. Sc. Degree in Physics from Gothenburg University. I work with “problems” in reverberation enhancement systems (RESs). A RES includes many electroacoustic channels (i.e. microphone, amplifier, loudspeaker) which means that one will get problems with feedback and system stability. In one type of RESs (called in-line RESs), it is extremely important to reduce acoustical feedback from loudspeaker to microphone. This is due to the risk of sound coloration and howlback phenomena. To reduce acoustical feedback one can modulate the signal that is fed to the loudspeaker(s). The most common type of modulation in RESs is delay modulation. However, if the output signal is too strongly modulated, a listener will think that the sound is colored. Therefore, the main goals of my project is to investigate what type of modulation a listener prefer and to find a subjectively accepted balance between modulation and feedback. Additionally, new objective measures that describe coloration due to feedback and modulation are under development.
- Psychoacoustic effects caused by feedback control (time variance) in reverberation enhancement systems.