Treatment Targets in Spanish and English Bilingual Speech Intervention

This study is a single-subject experimental design with staggered multiple baselines examining speech intervention for Spanish-English bilingual children with speech sound disorders. The study includes two arms based on the language of intervention (Spanish or English). Within each arm are two conditions that manipulate the linguistic complexity of the speech treatment target (simple consonant singleton or complex consonant cluster). Participants will be pseudo-randomly assigned to these arms and conditions.

The primary outcome is system-wide generalization; specifically, a) within-language and b) across-language generalization to untreated sounds. Accuracy data for the dependent variable will be derived from narrow phonetic transcription of participants' productions from speech probes in English and Spanish. The entire generalization probe is administered at each assessment visit (Pre, Post, and 1- and 2-Month Follow-Ups), and shorter subset probes targeting only monitored sounds are administered during Baselines and weekly during Treatment.

Inclusion criteria

• Participants will be regularly exposed to English for at least 3 months in one of the following ways: a) an English-speaking caregiver or sibling who interacts with the child on a daily basis in English, b) attendance at an English-speaking daycare, preschool, or elementary school.
• Caregivers will have reported concern with their child's speech development and/or reduced intelligibility on the Intelligibility in Context Scale in Spanish or English.
• Participants will present with 5 or more consonants or clusters missing from their phonetic inventories in each language to confirm presence of a speech sound disorder and sufficient gaps in phonological knowledge to warrant treatment.

Exclusion criteria

• Participants receiving speech or language treatment elsewhere during their participation in this project.