5. A speech synthesizing apparatus according to claim 4, wherein a speech waveform of a repetitious syllable sequence, which is obtained by repeating twice a two-syllable sequence or a three-syllable sequence, is stored in the speech waveform database by uttering the repetitious syllable sequence with the type-0 accent and by uttering the repetitious syllable sequence with the type-1 accent.
6. A speech synthesizing apparatus according to claim 5, wherein said speech waveform database is configured to store said speech waveform of the repetitious syllable sequence by storing a first speech waveform representing uttering the repetitious syllable sequence with the type-0 accent and a second speech waveform representing uttering the repetitious syllable sequence with the type-1 accent.