Patent ID: 8554565

Claim:
A speech synthesizer, comprising: a generation unit that selects speech segments for respective synthesis units to generate a speech segment sequence, which is a sequence of the speech segments; a speech connection unit that synthesizes speech by connecting the speech segments of the speech segment sequence generated by the generation unit; a specifying unit that specifies a degraded region of a first previously synthesized speech segment sequence that is synthesized by the speech connection unit; and a prohibition unit that compares the first previously synthesized speech segment sequence with a second speech segment sequence having a same given synthesis unit as the first previously synthesized speech segment sequence, over the specified degraded region of the first previously synthesized speech segment sequence, and based on the comparison, disables a speech segment in the first speech segment sequence that is not included in the second speech segment sequence, during all subsequent selections of speech segments by the generation unit, for the given synthesis unit.