To understand how socioeconomic status (SES) and bilingualism simultaneously operate on cognitive and sensory function, we examined executive control, language skills, and neural processing of sound in adolescents who differed in language experience (i.e. English monolingual or Spanish-English bilingual) and level of maternal education (a proxy for SES). We hypothesized that experience communicating in two languages provides an enriched linguistic environment that can bolster neural precision in subcortical auditory processing which, in turn, enhances cognitive and linguistic function, regardless of the adolescent's socioeconomic standing. Consistent with this, we report that adolescent bilinguals of both low and high SES demonstrate more stable neural responses, stronger phonemic decoding skills, and heightened executive control, relative to their monolingual peers. These results support the argument that bilingualism can bolster cognitive and neural function in low-SES children and suggest that strengthened neural response consistency provides a biological mechanism through which these enhancements occur.