Table 3.

Definitions of rhythm metrics and articulation rate measure derived for all speech materials.

Measure	Description
ΔV	Standard deviation of vocalic intervals.
ΔC	Standard deviation of consonantal intervals.
%V	Percent of utterance duration composed of vocalic intervals.
VarcoV	Standard deviation of vocalic intervals divided by mean vocalic duration (× 100).
VarcoC	Standard deviation of consonantal intervals divided by mean consonantal duration (× 100).
VarcoVC	Standard deviation of vocalic + consonantal intervals divided by mean vocalic + consonantal duration (× 100).
nPVI-V	Normalized pairwise variability index for vocalic intervals. Mean of the differences between successive vocalic intervals divided by their sum (× 100).
rPVI-C	Pairwise variability index for consonantal intervals. Mean of the differences between successive consonantal intervals.
nPVI-VC	Normalized pairwise variability index for vocalic + consonantal intervals. Mean of the differences between successive vocalic + consonantal intervals divided by their sum (× 100).
rPVI-VC	Pairwise variability index for vocalic and consonantal intervals. Mean of the differences between successive vocalic and consonantal intervals.
Articulation rate	Number of (orthographic) syllables produced per second, excluding pauses.

Note. For full details of pairwise variability index (PVI) calculations, see Grabe and Low (2002).