The Incursões deal with all components (including their coupling
relations) of a dynamical model of speech rhythm, named through out the
book the reference model, for practical reasons. The
computational-mathematical implementation of the model derives from
dynamical systems theory, and presupposes that the rhythmic system
underlying speech communication has three levels of coupling at three
distinct temporal scales. Seven hypotheses on or properties of speech
rhythm are sustained along the book: (1) speech rhythm is the result of
the coupling between a perception-related tendency to pattern
structuring, implemented by the inter-relation between local syntactic
information and a phrase stress oscillator, and a regularity face, e
production-related regularity constraint, implemented by the
oscillation of two components, a syllabic oscillator and a phrase
stress oscillator; (2) both tendencies, to pattern formation and to
regularity act at two distinct temporal scales, those of
syllable-sized, and stress group sized units; (3) the syllabic
oscillator has its pulses anchored at vowel onsets, implementing the
carrier component of speech rhythm; (4) prosodic timing, specified by
the coupled oscillators model, is functionally separated from the
specification of intrinsic gestures in a gestural lexicon; (5)
the reference model generates complex patterns of syllable-sized
durations via the consequences onto the syllabic oscillator from
entrainment by the phrase stress oscillator. These patterns reproduce
with precision those found on Brazilian Portuguese natural utterances;
(6) speech rate, specified underlyingly by the syllabic oscillator
resting period is a basic dynamical model property; (7) the model
exhibits dynamical properties found in natural speech, such as
adaptation, bifurcation, attraction to/repulsion from cyclic
attractors. The great amount of analysed data and argumentation
outlined in the book strongly suggest that the reference model is a
linguistically and biologically adequate model of speech rhythm, able
of integrating intonational and prosody perception.