In phonetics, an occlusive, sometimes known as a stop, is a consonant sound produced by occluding (i.e. blocking) airflow in the vocal tract, but not necessarily in the nasal tract. The duration of the block is the occlusion of the consonant. An occlusive may refer to one or more of the following, depending on the author:
Oral occlusive may mean any of the above apart from nasal occlusives, but typically means stop/plosive. Nasal occlusive may be used to distinguish the simple nasal sounds from other nasal consonants.
The terms 'stop' and 'occlusive' are used inconsistently in the literature. They may be synonyms, or they may distinguish nasality as here. However, some authors use them in the opposite sense to here, with 'stop' being the generic term (oral stop, nasal stop), and 'occlusive' being restricted to oral consonants. Ladefoged and Maddieson (1996) prefer to distinguish 'stop' from 'nasal'. They say,