Recent findings demonstrate a bilingual advantage for voice processing in children, but the mechanism supporting this advantage is unknown. Here we examined whether a bilingual advantage for voice processing is observed in adults and, if so, if it reflects enhanced pitch perception or inhibitory control. Voice processing was assessed for monolingual and bilingual adults using an associative learning identification task and a discrimination task in English (a familiar language) and French (an unfamiliar language). Participants also completed pitch perception, flanker, and auditory Stroop tasks. Voice processing was improved for the familiar compared to the unfamiliar language and reflected individual differences in pitch perception (both tasks) and inhibitory control (identification task). However, no bilingual advantage was observed for either voice task, suggesting that the bilingual advantage for voice processing becomes attenuated during maturation, with performance in adulthood reflecting knowledge of linguistic structure in addition to general auditory and inhibitory control abilities.

It is well established that people with autism have impaired face processing, but much less is known about voice processing in autism. Four experiments were therefore carried out to assess (1) familiar voice-face and sound-object matching; (2) familiar voice recognition; (3) unfamiliar voice discrimination; and (4) vocal affect naming and vocal-facial affect matching. In Experiments 1 and 2 language-matched children with specific language impairment (SLI) were the controls. In Experiments 3 and 4 language-matched children with SLI and young mainstream children were the controls. The results were unexpected: the children with autism were not impaired relative to controls on Experiments 1, 2 and 3, and were superior to the children with SLI on both parts of Experiment 4, although impaired on affect matching relative to the mainstream children. These results are interpreted in terms of an unexpected impairment of voice processing in the children with SLI associated partly, but not wholly, with an impairment of cross-modal processing. Performance on the experimental tasks was not associated with verbal or nonverbal ability in either of the clinical groups. The implications of these findings for understanding autism and SLI are discussed.