Tilt intonation model

The Tilt intonation model developed by Taylor [434] [439] [436] was developed with the explicit intent of creating a practical, engineering model of intonation. To this extent, issues of pmely linguistic concern (such as phonological rules in the AM model) or biological plausibility, as in the... 

Dusterhoff, K. E., Black, A. W., and Taylor, P. Using decision trees within the tilt intonation model to predict FO contours. In Proceedings of Eurospeech 1999 (1999). 

The models differ significantly in what they take as the primary form of intonation. In the AM model this is quite abstract while in the Tilt model this is quite literal or acoustie . These differences in primary form should not be taken to mean that the proponents of these models do not believe that there should be more abstract or more conerete representations, just that the best representation happens to lie where they describe it. In the many synthesis schemes based on the AM model there are other, more phonetic or acoustic levels, and in the Tilt model there is always the intention that it should serve as the phonetie description of some more abstract higher level representation. 

Fujisaki model were ignored. While the Tilt model is no more plausible as a means of intonation production that say concatenative synthesis, it was designed so that its parameters would have a clear linguistic interpretation. 

There is a basic distinction in most models as to whether intonation is an inherently tone or pitch-level based system (as in AM models), or whether it is based on pitch shapes or pitch dynamics (as in the Dutch model, Fujisaki model or Tilt). In theoretical linguistics this debate is seen as particularly important as researchers are attempting to find the true nature of intonation, with conclusive evidence occasionally being produced for one view over the other. The issue is hard to resolve, and it may be case where intonation is actually a mixture of both. 

Articles on all the models and techniques described here are readily available, but there are few which consider all models together and offer comparisons. The best account of the AM model is given by Ladd [269]. Ladd not only describes the model and its developmenL but also serves as a solid introduction to the whole field of intonational phonology and the practical phonetics associated with it. Accounts of the INTSINT model are given in Hirst [212], the Tilt model in Taylor [436], the Fujisaki model in Fujisaki [166], the SFC model in Bailly and Holm [31], the Dutch model in [447], the British school in O Connor and Arnold [333]. 

The Tilt model describes intonation with a sequence of events, each of which is described by a set of continuous parameters. 

Taylor, P. A. Analysis and synthesis of intonation using the tilt model. Journal of the Acoustical Society of America 107, 4 (2000), 1697-1714. 

Some models have a superimpositional nature (Dutch, Fujisaki) such that pitch accents are seen as being relatively short-term, riding on top of phrases, which are seen as being relatively long. By contrast, in linear models (AM/Tilt) contours are composed of linear sequences of intonational units. Often a grammar that states which units can follow each other is used, but, so long as the sequence lies within the grammar, any unit can foUow any other. 

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