4. The speech synthesis device according to claim 1 , wherein the central segment selection unit selects a central segment from among a plurality of speech segments that have a high degree of conformity with a language processing result of the language processing.
5. The speech synthesis device according to claim 4 , wherein the central segment selection unit comprises a second prosody generation unit for generating second prosody information based on the language processing result, and selects a central segment based on the second prosody information.