Extraction of voice from the center of the stereo image

Detection and extraction of the center vocal source is important for many audio format conversion and manipulation applications. First, we study some generic properties of stereo signals containing sources panned exactly to the center of the stereo image and propose an algorithm for the separation of a stereo audio signal into a center and side channels. Recently, Park et al. [Proc. 129th AES convention, London 2010, Preprint Paper 8071] presented the results of listening tests where the perceived widths of the stereo images were evaluated for synthetic signals. Given the center separation algorithm proposed in this paper, a similar experiment was carried out with realistic stereo audio contents. The results show that there are clear differences between the stimuli used in the two experiments, which are discussed in this paper based on the analysis of the test signals and their binaural characteristics in the listening test configuration.