Voice band enhancement apparatus and voice band enhancement method that generate wide-band spectrum

摘要

A voice band enhancement apparatus is used that includes a frequency transform unit to perform frequency transform on an input signal to calculate a spectrum, a mapping function calculating unit to calculate, by use of the spectrum, a mapping function for generating high-range components from low-range components of the spectrum, a wide-band spectrum generating unit to generate, in a higher range than a band of the spectrum, a high-range spectrum based on the mapping function and to integrate the generated high-range spectrum and the spectrum calculated by the frequency transform unit, thereby generating a wide-band spectrum wider than the band of the spectrum calculated by the frequency transform unit, and an inverse frequency transform unit to perform inverse frequency transform on the wide-band spectrum to calculate an output signal.