Extending Complexity to Word-Final Position via Telepractice: Intervention Effects for English-Speaking Children With Speech Sound Disorder.

Purpose: Phonologically complex targets (e.g., [pl-]) are understood to facilitate widespread gains following speech sound intervention, and yet, available research largely features word-initial clusters. The present study investigates intervention effects following treatment of complex clusters presented in word-final position. Importantly, this allows for an added layer of complexity via suffixes that mark tense and agreement.

Method: Eight English-speaking children with speech sound disorder (SSD; 3;3-6;9 [years;months]) participated in 18 one-on-one intervention sessions. Intervention was completed via telepractice, as were all pre- and post-intervention assessments. Intervention targets were word-final two-element consonant clusters that were unknown to the child prior to intervention. Targets were presented in verbs that were either monomorphemic (i.e., [-ks]; they mix) or bimorphemic (i.e., [-ks]; she pick/3s, marked for third-person singular).

Results: All participants demonstrated change across multiple phonological measures. More stringently, six of eight participants demonstrated generalization to untreated sounds and untreated words immediately following intervention, including four of four children with monomorphemic targets. Importantly, positive changes for children with both target types were observed following a relatively short course of intervention (18 sessions over 6 weeks), and mastery of the target cluster was not required for phonological growth to occur.

Conclusions: Results align with available work featuring word-initial complex targets and indicate that word-final consonant clusters are feasible, effective targets for English-speaking children with SSD. Findings similarly affirm the use of telepractice to deliver research-based interventions. Speech-language pathologists may thus integrate these findings with their clinical judgment and client perspectives to implement such targets in clinical practice.