This paper describes a quality enhancement system for band limited speech signals. In speech transmission, the quality of the received speech signals is degraded by severe band limitation. We have proposed a spectrum widening method that utilizes aliasing effects in sampling rate conversion and digital filtering for spectrum shaping. In this paper, a new method is proposed that offers improved performance in terms of the spectrum distortion characteristics. Implementation procedures are clarified, and its performance is discussed. The proposed method can effectively enhance speech quality.
Bibliographic reference. Yasukawa, Hiroshi (1995): "Enhancement of telephone speech quality by simple spectrum extrapolation method", In EUROSPEECH-1995, 1545-1548.