Final Thesis

Dynamic Crosstalk-Cancellation with Room Compensation for Immersive CAVE-Environments

Master Thesis of Röcher, Eric

Auralization of virtual scenes using binaural synthesis enables a realistic reproduction of auditory events, which intensifies the feeling of immersion in Virtual Reality applications. Headphones are usually used with binaural synthesis; however, they tend to constrain the users immersion. To retain the immersion, a speaker setup with a proceeding Crosstalk-Cancellation filter can be used. In large CAVE-VR-Systems with extensive acoustically hard projection surfaces, which partly or completely surround the user, challenging acoustical conditions are to be expected. Not only is the speaker’s placement limited to positions above the hard projection surfaces but furthermore, due to the non-absorbent surfaces, distinct early reflections superimpose the useful signal. This results in a not insignificant change in the overall reverberation time. Therefore a CTC filter design is proposed which compensates those early reflections. Based on the simple room geometry in CAVE-Environments, sound transmission paths can be easily estimated. These estimations can then be used to integrate room characteristics into the design of a dynamic CTC-system and lead to an improved playback quality for rooms with challenging acoustical conditions. The proposed procedure will be instrumentally reviewed for its performance in the aixCAVE, the VR-Environment of the RWTH Aachen University. The tests will focus on accuracy and introduced errors for each individual hardware as well as software component of the system. Inherent System latencies and positional inaccuracies like for example the CAVE’s tracking device and transmission path delays will be taken into consideration.