Computational Phonology: Merged, not Mixed

Research into text-to-speech systems has become a rather important topic in the areas of linguistics and phonetics. Particularly for English, several text-to-speech systems have been established (cf. for' example llertz (1982), Klatt (1976)). For Dutch, text-to-speech systems are being developed at the University of Nijmegen (cf. Wester (1984)) and at the Universities of Utrecht and Leyden and the Institute of Perception Research (IPO) Eindhoven as we]]. In this paper we will be concerned with the grapheme-to-phoneme conversion component as part of the Dutch text-to-speech system which is being developed in Utrecht, Leyden and Eindhoven. One of our primary interests is that the grapheme-to-phoneme system not only has to generate the input for speech synthesis, either in allophone or diphone form, but that it had to be used for other ~ urposes as well. Thus, the system has to satisfy the -ollowing demands: its output must form a proper and flexible input for diphone as well as allophone synthesis; it must be possible to easily generate phonematized lists on the basis of orthographic input; it must be possib].e to automatically obtain information regarding the relation between graphemes and phonemes in texts; the system has to be user-friendly, so that it can be addressed by linguists without computer training (for example to test their phonological rules). In our view, there are two aspects to a grapheme-to-phoneme conversion system: a linguistic and a computational one. The linguist, in fact, provides the grammar necessary for the conversion and the engineer implements this grammar into a computer system. Thus, knowledge about spelling and linguistics are separated from the technical implementation: the linguist provides the rules and the system executes them. The two components will also constitute the main sections of this paper.