Autosegmental-Metrical and ToBI models

The AM model describes intonation as a series of high and low tones. By using a system of diacritics that distinguish tones located on accented syllables from those occurring at 

Hgure 9.9 An example of a standardised contour in the Dutch system. The dashed hnes denote the three declination lines and the thicker solid line shows the path of the FO contour. The first excursion to the top declination line is a head accent (British school). The second accent, which rises to the top line and then falls to the baselines, is a fall accent. The rise at the end is a continuation rise. 

Unlike in the British-school analysis, there is no strict division of the contour into regions such as head and nucleus. Both nuclear and pre-nuclear accents can be any one of the six types described above. The nucleus accent is distinguished because the phrase and boundary tones that follow it allow a much larger inventory of intonational effects. 

The history of the AM model is particularly interesting in that it has a dual character of being intended as a pure linguistic theory in the MIT, Chomsky/Halle phonology tradition and as a working model for the Bell Labs TTS system. It is important to realise that, from a theoretical linguistic point of view, the model as just described is not intended to be a complete model of intonation as used in human communication. 

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