Recognition of vocoded speech in English by Mandarin-speaking English-learners

•The L2 listeners showed less improvement in phoneme recognition accuracy as a function of number of channels, which was associated with the phoneme confusions due to the L1 impact.•The L2 listeners were less effective than L1 listeners in applying contextual information and linguistic knowledge to sentence recognition.•The facilitating role of contextual cues in sentence recognition was consistently present in the L2 listeners.•The L2 listeners required more spectral information to maximize the contextual benefit in comparison to the L1 listeners.•The overall perceptual performance of the L2 listeners was positively correlated with and predicted by the length of residence in the U.S.