Effect of word phonetic properties on stuttering anticipation and speech production in adults who stutter.

Purpose: Stuttering anticipation is a significant factor in an individual's stuttering experience. People who stutter have reported words and sounds that they anticipate stuttering on. Attempts at understanding the association between stuttering anticipation and stuttering outcomes and the impact of phonetic properties on stuttering anticipation and overt stuttering have been insufficiently examined. This study aims to address these important issues.

Methods: Data were collected as part of a larger brain imaging study. Twenty adults who stutter rated a 414 word-list on stuttering anticipation. Participant-specific 'high' and 'low' anticipated words were selected. Twelve of the 20 participants returned for a second session 2-11 weeks later, during which they read the selected words again and stuttering occurrence was recorded.

Results: Among the 20 participants, three sub-groups with "high" (N = 6), "moderate" (N = 5) and "low" (N = 9) stuttering anticipation were identified. Significant "high stuttering" anticipation was found on consonants, plosives, bilabials and alveolars, as well as labials and coronals. In 5 of the 8 participants who stuttered during session 2, more than 80 % of words stuttered were previously rated with high anticipation. Consonants, plosives, bilabials and alveolars, and labials and coronals were the most frequently stuttered (>27 %).

Conclusion: While not all adults who stutter demonstrate high word-specific stuttering anticipation, we found that more than half anticipated this to a high degree. Furthermore, both word-specific phonetic properties and stuttering anticipation impact stuttering occurrence. The inclusion of word-specific stuttering anticipation ratings may increase the likelihood of stuttering in experimental studies and improve treatment outcomes through individualized intervention.