A scheme for concatenating units for speech synthesis

In previous papers we discussed a speech synthesis by rule scheme where segments obtained from natural speech were linearly concatenated. These segments included the consonants and the transitions from consonants to vowels, vowels to vowels, and vowels to consonants. Each synthesis parameter was defined by few sets of LPC area parameters, and in the concatenative process, straight line interpolation was used to obtain the complete set of area parameters. Informal listening and some formal intelligibility testing revealed that this simplified description of the synthesis segments was not sufficient to produce the speech quality that would satisfy us. Consequently, it was decided to improve the definition of the concatenative units. This paper will discuss in detail the scheme for synthesis employing these concatenative units.