Subband Processing for Spatially Robust Room Impulse Response Reshaping
Radoslaw Mazur, Fabrice Kutzberg, Martina Böhme, Alfred Mertins · 2018
The perceived quality of a sound played in a closed room is often degraded by the added reverberation. In order to combat these effects, the methods of room impulse response equalization may be used. Typically, properties of the human auditory system, such as temporal masking, are used for a better control of the late echoes. This is accomplished by designing prefilters which modify the played signals and render the echoes inaudible at a given position. Small spatial mismatch usually results in reduced performance and bigger offsets even yield added reverberation. This problem can be tackled by simultaneously reshaping multiple positions in the listening area, but it requires a huge amount of impulse responses. In this work we propose to mitigate this burden by equalizing only certain frequency components of the room impulse responses. When equalizing only the low frequencies, the mismatch and the degradation can be reduced. This allows for less measurements in the listening area, where a human listener is able to move freely.