Predicting language dominance in Spanish/English bilingual adults based on relative speech-in-speech recognition scores

Purpose: Multiple dimensions of language dominance, such as language proficiency and demand for language use, can be reflected in bilinguals' speech-in-speech recognition scores. This paper explores the feasibility of using a novel measure to estimate language dominance for bilinguals: relative speech-in-speech recognition thresholds (SRTs) or the within-person difference in SRTs between their two languages. Method: Participants were 25 Spanish/English bilingual adults (M-age = 30 years). SRTs for sentence recognition in a language-matched two-talker masker were measured in English and in Spanish using an adaptive, open-set task. Relative SRTs were calculated by subtracting the Spanish SRT from the English SRT. Language dominance and proficiency were assessed by established measures. Analysis: Spearman correlations were used to assess the association between measures. Findings: Relative SRTs were correlated with dominance scores derived from both a questionnaire (r(s) = -.80) and standardized testing (r(s) = -.80). Originality: We tested and validated a novel measure, relative SRTs, to predict language dominance in bilingual adults. This time-efficient method could be used by bilingual researchers interested in assessing language dominance for descriptive or experimental purposes. Significance: Relative SRTs show promise as a valid method to assess language dominance in Spanish/English bilingual adults.