Exchange of disfluency with age from function words to content words in spanish speakers who stutter.

The main purpose of the present study was to examine whether the developmental change in loci of disfluency from mainly function words to mainly content words, observed for English speakers who stutter (P. Howell, J. Au-Yeung, & S. Sackin, 1999), also occurs for comparable Spanish speakers who stutter. The participants were divided into 5 age groups. There were 7 participants in Group 1, from 3 to 5 years old; 11 in Group 2, from 6 to 9 years old; 10 in Group 3, from 10 to 11 years old; 9 in Group 4, from 12 to 16 years old; and 9 in Group 5, from 20 to 68 years old. Across all groups, 36 of the 46 participants were male. The study method involved segmenting speech into phonological words (PWs) that consist of an obligatory content word with optional function words that precede and follow it. The initial function words in the PWs were examined to establish whether they have a higher disfluency rate than the final ones (J. Au-Yeung, P. Howell, & L. Pilgrim, 1998). Disfluency on function words in a PW was higher when the word occurred before a content word rather than after a content word for all age groups. Disfluencies on function and content words were then examined to determine whether they change over age groups in the same way as for English speakers who stutter (Howell et al., 1999). The rate of disfluency on function words was higher than that on content words, particularly in the youngest speakers. Function word disfluency rate dropped off and content word disfluency rate increased across age groups. These patterns are similar to those reported for English. Possible explanations for these similarities across the two languages are discussed.