Chapter14---14.3.3.2~14.5

14.3.3.2 Prosodic effects on iceberg invariance

1. syllable magnitude (excursion)
- In order to remove this prosodic effect on movement speed, we need to measure the excursion as reflection of syllable magnigude.
- The effect of increased syllable magnitude may be observed mainly by the shift in time of the elemental gesture, away from the syllable center, without affecting the speed.

2. following boundary magnitude
- This effect is interpretable in a simple way if the effect of phrase-final lengthening due to the boundary is simply adjustment of the time scale toward the end of the phrase and the excursion magnitude is significantly affected by boundary magnitude only due to coarticulartory undershooting.



14.3.3.3 Segmentation for syllable duration and articulatory gap measurement

1. preformed by the program "ubedit"
- ubedit displays the articulatory trackings from the x-ray microbeam data and aligns them with the corespoding waveform and spectrogram.


14.4 Results
14.4.1 Relation of speed with articulatory syllable duration

1. scatterplots of the speed vs. articulatory ayllable duration in initial and final demisyllables
- The speed of the lower lip movement at the ice berg threshold was considered separately for the initial and final demisyllables in the word "five".
- slower speed for emphasized syllables in phrase-final position
- the latter syllables seem to have a relatively small syllable magnitude while being affected by final leanthening.


14.4.2 Relation of speed with aritculatory gap duration

1. The scatterplots indicate a weak negetive correlation of threshold crossing speed and gap duraion, showing longer gaps after all final digits.


14.4.3 Correlations of excursion, syllable duration, and boundary strength with speed

1. high percentages
- are accounted for by its linear relationship with the predictor variables in this syllable position.

2. lower percentages
- are accounted for by the same linear combination of predictors in fianl demisyllables

3. excusion in the present data appears to be the greater contributor to the prediction of speed for all speakers


14.5 Discussion

1. The results show evidence for speaker-specific treatment of the prosodic parameters of syllable duraion and boundary strength, in relation to implemetation of the velocity patterns of crucial articulator movements, both in initical and fianl demisyllables.

2. The clear relation between speed and excursion, shown by the cosistent significant influence of excursion on velocity of the movement at iceberg threshold crossing.

3. Overall prosodic rhythmic structure of the utterance has to be taken into account in predictin duraion, timing, and excursion of consonantal gestreus within the syllable.

4. Excursion reflects strong nonlinear effects of the speech-singal generating mechanism such as xonsonantal gesture saturation, while syllable duraiotn is less affected by such peripheral effects.