Table 3.

Speech features (12 features).

Syllable count: Number of syllables produced by the speaker, as estimated using the Praat script of De Jong and Wempe (2009) (1 feature).

Pause count: Number of pauses longer than 150 ms (1 feature).

Duration: Total duration of the speech sample (1 feature).

Phonation time: Total duration of time spent in speech (i.e., excluding silent pauses) (1 feature).

Proportion of time spent speaking: Phonation time divided by total duration (1 feature).

Speech rate: Number of syllables, divided by total duration (1 feature).

Average syllable duration (ASD): Phonation time, divided by number of syllables (1 feature).

Pauses per syllable: Number of pauses, divided by total number of syllables (1 feature).

Pause rate: Number of pauses, divided by total duration (1 feature).

Pause duration (mean and s.d.): The mean and standard deviation of the duration of pauses >150 ms (2 features).

Maximum pause duration: Maximum pause length over all pauses in the sample (1 feature).