Linguistic stress, within-word position, and grammatical class in relation to early childhood stuttering

The purpose of the present study was to investigate whether the link that has been established between stuttering and linguistic stress in adolescents and adults (the so-called stress effect) can also be observed in childhood stuttering. To account for confounding variables, both within-word position and grammatical class were measured, because these factors covary with linguistic stress. Speech samples of 22 preschool children (mean time of 9 months since onset of stuttering) were analyzed. The relative stress of each syllable was rated and syllables were categorized into long and short stressed, unstressed, and intermediately stressed syllables. Results showed that 97.8% of stuttering events occurred on first syllables of words and 76.5% on the first sound of syllables, that means a clear word-initial effect. Stuttering frequency on first syllables of function words was 16.9% and significantly higher than the frequency of stuttered first syllables of content words (11.5%). In function words short stressed syllables and intermediately stressed syllables were stuttered more often than unstressed syllables. The analysis for individual disfluency types revealed that, for function words, stuttering on short stressed syllables was associated with prolongations and syllable repetitions. However, in intermediately stressed syllables stuttering coincided most often with one-syllable word repetitions. This differentiation of the stress effect may suggest different causal mechanisms underlying these disfluency types. Educational objectives: The reader will learn about and be able to: (1) describe how within-word position, grammatical class, and linguistic stress effect stuttering frequency in preschool children who stutter; (2) explain how the occurrence of individual disfluency types depends on linguistic stress; (3) discuss how patterns of adults and preschool children who stutter differ in regard to these aspects.