Native listeners rely on rhythmic cues when deciding on the nativeness of speech

Foreign-accented speech typically deviates segmentally and suprasegmentally from native-accented speech. Two experiments were conducted to investigate the role of amplitude envelope (ENV), segment duration (DUR), and speech rate (SR) on Italian listeners' ability to identify native-accented Italian in utterances produced by Zurich German speakers. In experiment 1, listeners judged in a two-alternative forced-choice perception task which of the two stimuli in a trial they perceived as more native-like. Stimuli in each trial only varied in ENV and DUR, which were retrieved either from a native Italian speaker [first language (L1) donor] or from a German speaker of Italian [second language (L2) donor]. Results revealed that listeners make use of both DUR and ENV to identify the more native-like stimuli, but the effect of ENV was more subtle. In experiment 2, SR differences (resulting from native and non-native segment duration differences in experiment 1) were normalized for. It was found that this drastically reduced the effect of segment durations in terms of perceived nativeness; however, the ENV effect still remained. This was not the case in a control group of listeners without competence in Italian. Though effects were subtle, the study shows that ENV cues contribute to the percept of nativeness in L2 speech.