Apparatus for expanding speech bandwidth

摘要

Apparatus for expanding the bandwidth of speech signals such that a narrowband speech signal is input and digitized (101), the spectral envelope information and residual information are extracted from the digitized signal by linear predictive coding analysis (107), the spectral envelope information is expanded into wideband information by a spectral envelope converter (109), the residual information is expanded into wideband information by a residual converter (110), the converted spectral envelope information and residual information are combined (108) to produce a wideband speech signal, frequency information not contained in the input signal is extracted from the obtained wideband speech signal by a filter (105), and the resulting signal is added (103) to the original digitized input signal, and the obtained signal is converted (104) into an analog signal as the output signal of the apparatus.