Language history is an important factor in masked speech recognition. Listeners who acquire the target language later in life perform more poorly than native speakers. However, there are inconsistencies in the literature regarding performance of bilingual speakers who begin learning the target language early in life. The purpose of this experiment was to evaluate speech-in-noise and speech-in-speech recognition for highly proficient early bilingual listeners compared to monolingual and late bilingual listeners.

Three groups of young adults participated: native monolingual English speakers, bilingual Mandarin–English speakers who learned English from birth (early bilinguals), and native Mandarin speakers who learned English later in life (late bilinguals). All participants had normal hearing and were full-time college students. Recognition was assessed for English sentences in speech-shaped noise and two-talker English speech. Participants provided linguistic and demographic information, and late bilinguals completed the Versant test of spoken English abilities.

All listeners performed better in speech-shaped noise than two-talker speech. Performance was similar for monolingual and early bilinguals. Late bilinguals performed more poorly overall. There was evidence for a stronger association between masked speech recognition and English dominance for late bilinguals compared to early bilinguals.

These results support the conclusion that bilingualism itself does not necessarily result in a disadvantage when recognizing masked speech in noise and speech in speech. For populations similar to those studied here (highly proficient early bilinguals), it would be appropriate to evaluate masked speech recognition using the same simple stimuli and normative data used for monolingual speakers of English.