Phonological neighborhood and word frequency effects in the stuttered disfluencies of children who stutter

Abstract

Purpose: The purpose of this study was to examine (a) the role of neighborhood density (number of words that are phonologically similar to a target word) and frequency variables on the stuttering-like disfluencies of preschool children who stutter, and (b) whether these variables have an effect on the type of stuttering-like disfluency produced.

Method: A 500+ word speech sample was obtained from each participant (N = 15). Each stuttered word was randomly paired with the firstly produced word that closely matched it in grammatical class, familiarity, and number of syllables/phonemes. Frequency, neighborhood density, and neighborhood frequency values were obtained for the stuttered and fluent words from an online database.

Results: Findings revealed that stuttered words were lower in frequency and neighborhood frequency than fluent words. Words containing part-word repetitions and sound prolongations were also lower in frequency and/or neighborhood frequency than fluent words, but these frequency variables did not have an effect on single-syllable word repetitions. Neighborhood density failed to influence the susceptibility of words to stuttering, as well as the type of stuttering-like disfluency produced.

Conclusions: In general, findings suggest that neighborhood and frequency variables not only influence the fluency with which words are produced in speech, but also have an impact on the type of stuttering-like disfluency produced.

Figure 1

Mean (and standard error of the mean) frequency values (y-axis expressed per million) for words containing part-word repetitions (PWR) and control words (n = 15), single-syllable word repetitions (SSWR) and control words (n = 15), and sound prolongations (SP) and control words (n = 6) for children who stutter between the ages of 3;0 (years;months) and 5;2.

Figure 2

Mean (and standard error of the mean) neighborhood density values (y-axis refers to the number of phonologically similar neighbors) for words containing part-word repetitions (PWR) and control words (n = 15), single-syllable word repetitions (SSWR) and control words (n = 15), and sound prolongations (SP) and control words (n = 6) for children who stutter between the ages of 3;0 and 5;2.

Figure 3

Mean (and standard error of the mean) neighborhood frequency values (y-axis expressed per million) for words containing part-word repetitions (PWR) and control words (n = 15), singlesyllable word repetitions (SSWR) and control words (n = 15), and sound prolongations (SP) and control words (n = 6) for children who stutter between the ages of 3;0 and 5;2.