Korean text-to-speech and concatenation cost function

The concatenation cost function is a key factor affecting the naturalness of synthesized speech.Previous research on concatenation cost functions has only discussed whether the characteristic vectors are the same at the concatenation point,but had not considered the first-order continuity.This paper describes a Korean text-to-speech(TTS) system based on triphones and the influence of the dynamic features of the triphones on concatenation.A concatenation cost function was developed which incorporates dynamic continuity by calculating the cost vector using the characteristic vectors and their first derivatives at the concatenation point.Test results show that the concatenation cost function improves continuity at the unit boundaries to substantially improve the naturalness of the Korean text-to-speech system.