| 摘要 |
PROBLEM TO BE SOLVED: To provide a voice band expansion device capable of obtaining an extended voice signal in response to an utterer of a narrow band voice signal without increasing a storage volume of a code book for converting the narrow band voice signal into a wide band voice signal. SOLUTION: Not only a pronunciation is outputted but also the code book is updated when a communication device mounted with the voice band expansion device receives the wide band voice signal. The received wide band voice signal and a band-narrowed signal thereof are analyzed in updating, and frequency contours are obtained with respect to the respective to signals. An updating object in the code book is determined based on the frequency contour obtained about the band narrowed signal, and learning is carried out to reflect the frequency contour obtained about the wide band voice signal. The learnt code book is applied to extend a band when the communication device receives the narrow band voice signal. COPYRIGHT: (C)2011,JPO&INPIT |
