Central auditory processing in bilinguals

The majority of the world’s population is bilingual. Bilingualism is a form of sensory enrichment that translates to gains in cognitive abilities; these cognitive gains in attention and memory are known to modulate subcortical processing of auditory stimuli. Second language acquisition has a broad impact on various psychological, cognitive, memory, and linguistic processes. Central auditory processing (CAP) is the perceptual processing of auditory information. Due to its importance in bilingu alism, this study aimed to review the CAP of bilinguals.

The CAP was studied in three areas: dichotic listening, temporal processing, and speech in noise perception. Regarding dichotic listening, studies have shown that bilinguals have better performance in staggered spondaic word (SSW) test, consonant-vowel dichotic test, dichotic digits test (DDT), and disyllable dichotic test than monolinguals, although similar results have also been reported in SSW and DDT. Regarding temporal processing, the results of bilinguals do not differ from those of monolinguals, although in some cases, it is better in bilinguals. Regarding speech in noise perception, the results between bilinguals and monolinguals are varied depending on the amount of linguistic information available in the stimuli.

Bilingualism has a positive effect on dichotic processing, no effect on temporal processing, and varied effect on speech in noise perception. Bilinguals have poor performance using meaningful speech and better performance using meaningless speech.