Purpose: The goal of this study was to examine how vocabulary size and inhibitory control affect word learning in bilingual (English-Spanish) children with hearing loss. Experiment 1 examined whether children with larger vocabularies learn and retain more words than children with smaller vocabularies. Experiment 2 examined whether children with better inhibitory control learn and remember more words than children with poorer inhibitory control. In addition, monolingual and bilingual children with and without hearing loss were compared on word learning and inhibitory control tasks.
Method: Seventy-three children between 8 and 12 years of age participated in the study. Forty children had normal hearing (20 monolingual and 20 bilingual) and 33 had hearing loss (20 monolingual and 13 bilingual). For Experiment 1, children completed a receptive vocabulary test in English and Spanish and three word learning tasks consisting of a training and a retention component in English, Spanish, and Arabic. For Experiment 2, children completed the flanker task for inhibitory control.
Results: In Experiment 1, larger total (English + Spanish) receptive vocabularies were predictive of better word training outcomes in all languages and better Spanish word retention, after controlling for age, degree of hearing loss, and maternal education. Children with hearing loss performed more poorly in Spanish and Arabic word training and retention than children with normal hearing. No differences were observed between children with normal hearing and hearing loss in English word learning. In Experiment 2, inhibitory control only predicted English retention outcomes. Children with hearing loss showed poorer inhibitory control than hearing peers. No differences were observed between monolingual and bilingual children, with and without hearing loss, in word learning or inhibitory control.
Conclusions: Language experience (measured by total vocabulary size) helps children learn new words and therefore children with hearing loss should receive well-fitted hearing aids and school accommodations to provide them with access to spoken language. Bilingual exposure does not impair nor facilitate word learning. Bilingual children showed similar difficulties with word learning and inhibitory control as monolingual peers with hearing loss. Hearing loss, probably via language deprivation, has broad effects on children’s executive function skills.