School Papers

The people having seriously defective vision [3] and

The concept of reproducing sound with more than two loudspeaker setups is not
novel. It has been a while since the first time surround reproduction systems have
been installed for domestic and automotive use, with the 5.1 setup being the most
frequently used 1. The evolving technology has also yielded audio signal transmis-
sion with broad spectral bandwidth, highly effective spatial sound recording tech-
niques and configurations incorporating multiple loudspeakers. For instance, in 7.1
the angle is decreased among loudspeakers, whereas as mentioned in 2, elevated
loudspeakers are introduced in systems like 9.1 11.1. In addition, the fast paced de-
velopment of virtual reality video has emerged the need for 3-D audio reproduction.
Spatial sound has also gained ground in critical applications associated with route
guidance of people having seriously defective vision 3 and with flight navigation
systems 4.

It is apparent that, spatial sound systems have to be able to interact with dif-
ferent audio channel formats, because it’s not always technically-and financially-
advantageous to use recording techniques, typical for every reproduction system
11. Thus, compatibility turns out to be a very important issue. Besides, the vast
majority of commercial music is recorded in stereo format. Therefore, certain signal
processing techniques have to be employed, in order to convert the stereo recordings
to multichannel formats, maintaining the quality of audio information and enhancing
the listening experience.

Extensive research has been conducted for spatial audio processing 6, 7 and spatial
audio coding, which comprises spatial audio scene coding (SASC) 5 and directional
audio coding (DirAC) 8. The aim is to decompose the input audio signal into non-
diffuse and diffuse sound. The calculated diffuse sound in the channels differs for
positive and negative correlations, which deviates from the ambience definition given
in the primary-ambience extraction framework investigates in the present thesis. In
SASC, the the Gerzon localization vector 9 is used to carried out localization
analysis, separately for both the separated components. In DirAC, the primary
sound is rendered applying vector base amplitude panning (VBAP) 10, while the
diffuse sound is decorrelated and played back by rear loudspeakers. The aim for
these signal processing techniques is to achieve spatial sound reproduction with
every sound system configuration