A new sound image broadening control system using a correlation coefficient variation method

• Published in: Electronics & communications in Japan. Part 1, Communications Communications, 1984, Vol.67 (6), p.33-41
• Main Authors: Kurozumi, Kohichi, Ohgushi, Kengo
• Format: Article
• Language: English
• ISSN: 8756-6621; 1520-6424
• DOI: 10.1002/ecja.4400670606

After examining the conventional quasistereophonic system, this paper presents the bandwidth division system and the phase shift system as two new types of quasistereophonic systems. These two new systems are based on the understanding that “if the correlation coefficient of a two‐channel acoustic signal is zero (and independent), the sensation of acoustic spreading is a maximum.” It is shown that the correlation coefficient of the two‐channel acoustic signals obtained by means of these systems approaches 0. In addition, using a computer simulation of the quasi‐stereophonic system of frequency‐division type, psychological tests were conducted. the tests showed that differences in sound image quality were principally due to sound image broadening sensations and distance sensations, and that those characteristics corresponded physically to the absolute value of the correlation coefficient and to the correlation coefficient itself. Further, if the correlation coefficient is zero, the sound image is perceived to be broadened to about the extent of the speaker separation, thus verifying the effectiveness of the new broadening sensation control system.