People who speak more than one language may benefit from improved auditory ability and attention, a study suggests.
Scientists at Northwestern University in the US enrolled 23 bilingual teenagers and 25 teenagers who only spoke English to look at their brainstem responses to complex sounds.
Participants listened to speech sounds in two conditions - against a quiet background and against a backdrop of background noise.
The researchers found that bilingual teens were much better at encoding the frequency of speech sounds, giving them advantages in auditory attention.
Viorica Marian, an expert in bilingualism at Northwestern, said that the ability to speak two different languages appears to promote "experience-dependent changes in the fundamental encoding of sound in the brainstem".
"It seems that the benefits of bilingualism are particularly powerful and broad, and include attention, inhibition and encoding of sound," she added.
The findings are published in the Proceedings of the National Academy of Sciences and follow earlier research showing that bilinguals may have cognitive advantages over monolinguals.