A set of concatenative units for speech synthesis
Joseph P. Olive, Mark Yoffe Liberman · The Journal of the Acoustical Society of America · 1979
In a previous paper [J. P. Olive, “Rule Synthesis of Speech From Dyadic Units”, IEEE International Conference on Acoustics, Speech and Signal Processing, 568–570, (1977)], we discussed a speech synthesis by rule scheme where the segments used for synthesis were obtained from natural speech. 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 two 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 kind of speech that would satisfy us. Consequently, it was decided to expand the definition of the set of concatenative units. Specifically: (1) the number of phonetic segments defining a synthesis unit can vary from one to three; (2) arbitrary number of area parameter vectors can be stored for a given synthesis unit; and (3) a facility is provided for expressing transition durations and amplitude rules for synthesis units or classes of units. This paper will discuss the details of a more complete and accurate set of concatenative units.