Lexicality and intensity in speech intervention (Cummings et al., 2018)

<div><b>Purpose: </b>This study examined how lexical representations and intervention intensity affect phonological acquisition and generalization in children with speech sound disorders.</div><div><b>Method:</b> Using a single-subject multiple baseline design, 24 children with speech sound disorders (3;6 to 6;10 [years;months]) were split into 3 word lexicality types targeting word-initial complex singleton phonemes: /ɹ l ʧ θ/. Specifically, academic vocabulary words, nonwords (NWs), and high-frequency (HF) words were contrasted. Intervention intensity was examined by comparing the performance of 12 children who completed eleven 50-min sessions (4 children/word type) to the performance of 12 who completed 19 sessions (4 children/word type). Children’s production accuracy of their treated phonemes and overall percent consonants correct values were used to measure phonological generalization via percentage accuracy scores and d scores. </div><div><b>Results:</b> All word lexicality conditions elicited phonological change, suggesting that academic vocabulary words, NWs, and HF words are viable intervention targets. Group mean averages were similarly high for the NWs and HF words, although children in the NW condition demonstrated more consistent phonological gains. Children who received 19 intervention sessions achieved 6 times more gains in treated sound accuracy than did children who received 11 sessions.</div><div><b>Conclusions: </b>Word lexicality did not significantly influence children’s intervention outcomes. More intensive intervention, as characterized by the number sessions, resulted in greater phonological change than did a shorter intervention program. Intervention intensity outcomes should be considered when establishing best practices for speech intervention scheduling.</div><div><br></div><div><b>Supplemental Material S1. </b>Neighborhood density, phonotactic probability, Kučera and Francis (1967) word frequency (WF), log 10 WF, and age of acquisition (in years) measurements (AoA) for the academic vocabulary (AV) words.</div><div><br></div><div><b>Supplemental Material S2.</b> Neighborhood density and phonotactic probability measurements for the nonwords (NWs).</div><div><br></div><div><b>Supplemental Material S3. </b>Neighborhood density, phonotactic probability, Kučera and Francis (1967) word frequency (WF), log 10 WF, and age of acquisition (in years) measurements (AoA) for the high-frequency (HF) words.</div><div><br></div><div><b>Supplemental Material S4. </b>Intervention fidelity data sheet for Imitation phase.</div><div><br></div><div><b>Supplemental Material S5.</b> Intervention fidelity data sheet for Spontaneous Production phase.</div><div><br></div><div><b>Supplemental Material S6. </b>Number of intervention trials (i.e., treatment dose) for each session and all children. Gray boxes identify sessions included in the intervention fidelity assessment.</div><div><br></div><div>Cummings, A., Hallgrimson, J., & Robinson, S. (2018). Speech intervention outcomes associated with word lexicality and intervention intensity.<i> Language, Speech, and Hearing Services in Schools.</i> Advance online publication. https://doi.org/10.1044/2018_LSHSS-18-0026 </div>