International audience The present research addresses three issues in the phonetics of Hanoi Vietnamese: (i) What are the airflow characteristics of the obstruent-final rhymes? (ii) Rhymes with final nasal consonants /m/, /n/, /ŋ/ show no acoustic trace of the final nasal segment when they carry tone B2 (orthographic tone nặng); does the nasal airflow on these rhymes differ significantly from what is observed on obstruent-final rhymes (which, from a phonological point of view, do not have any nasal segment)? (iii) How often are nasal-final, glottally constricted rhymes followed by a nasal release, and is this release similar to the nasal release which has been reported for rhymes with final obstruents /p/, /t/, /k/? Nasal airflow measurements of 391 syllables read by one speaker (and supporting data from two other speakers) go to show that nasal airflow does not distinguish successfully between nasal-final rhymes carrying tone B2 and obstruent-final rhymes, and that unvoiced nasal release is more frequent after obstruents /p/, /t/, /k/ than after B2-tone rhymes ending in nasals. By contrast, simultaneously recorded oral airflow brings out a clear difference between these two sets of rhymes, confirming that voice quality plays a key role in maintaining the distinction between these rhymes, which are similar from the point of view of oral articulation.