Patent ID: 7945446

Claim:
A sound processing apparatus comprising: a pitch detection section that detects a pitch of an input sound; an envelope detection section that detects a spectrum envelope of the input sound; a spectrum acquisition section that acquires converting spectrums that are frequency spectrums of a converting sound comprising a plurality of sounds; a spectrum conversion section that generates output spectrums created by imparting the spectrum envelope of the input sound, detected by said envelope detection section, to the converting spectrums acquired by said spectrum acquisition section; and a sound synthesis section that synthesizes a sound signal on the basis of the output spectrums generated by said spectrum conversion section, wherein said plurality of sounds included in said converting sound have been sounded in parallel from different sound sources, said converting spectrums having a plurality of peaks, a band of each of the peaks being wider than a corresponding band of each peak of spectrums of the input sound, and wherein, as data representative of the converting spectrums acquired by said spectrum acquisition section, said spectrum acquisition section supplies, for each spectrum composing the converting spectrums, unit data composed of data indicative of a frequency and intensity of the spectrum at the frequency, and wherein said spectrum conversion section includes: a pitch conversion section that varies, in accordance with the pitch of the input sound detected by said pitch detection section, the frequency indicated by the unit data of each spectrum of the converting spectrums; and an envelope adjustment section that adjusts a spectrum envelope of the converting spectrums, having the frequencies varied by said pitch conversion section, to substantially agree with the spectrum envelope of the input sound detected by said envelope detection section, wherein, for each of the peaks in the converting spectrums, said envelope adjustment section determines an intensity of a frequency in the spectrum envelope of the input sound, said frequency in the spectrum envelope of the input sound corresponding to the frequency of the peak in the converting spectrum, determines a ratio between the determined intensity of the frequency in the spectrum envelope of the input sound and the intensity of a frequency in the converting spectrums as indicated by the unit data, said frequency in the converting spectrum corresponding to the peak in the converting spectrum, and multiplies an intensity of the unit data of each spectrum belonging to the band centered around said peak in the converting spectrums, by the determined ratio, wherein the spectrum envelope of the converting spectrums substantially agree with the spectrum envelope of the input sound.