This paper describes an experiment designed to investigate the relative contributions of intonation and duration to the intelligibility of Norwegian as a second language (N2). Recordings of Norwegian sentences read by speakers of 7 different native languages (L1s) were used. The global intonation and the phoneme durations of each N2 utterance were manipulated so as to match a native Norwegian speakers productions of the same sentences. A perception experiment was carried out in which native Norwegian listeners wrote down what they perceived of each N2 sentence. Intonation manipulation is shown to enhance the N2 intelligibility for the English and German L1 groups. Duration manipulation is shown to enhance the N2 intelligibility for the French, Tamil and Persian L1 groups. For the English, German, Tamil and Russian L1 groups intonation contributes more to N2 intelligibility than duration. For the French speakers duration contributes more to N2 intelligibility than intonation.