This study is concerned with the identifiability of intonational phrase boundaries across familiar and unfamiliar languages. Four annotators segmented a corpus of more than three hours of spontaneous speech into intonational phrases. The corpus included narratives in their native German, but also in three languages of Indonesia unknown to them. The results show significant agreement across the whole corpus, as well as for each subcorpus. We discuss the interpretation of these results, including the hypothesis that it makes sense to distinguish between phonetic and phonological intonational phrases, and that the former are a universal characteristic of speech, allowing listeners to segment speech into intonational phrase-sized units even in unknown languages.