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:
Examples in English are (voiced) pronounced as /link/, pronounced as /link/, pronounced as /link/ and (voiceless) pronounced as /link/, pronounced as /link/, pronounced as /link/.
Examples in English are pronounced as /link/, pronounced as /link/, and pronounced as /link/.
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,
Note that what we call simply nasals are called nasal stops by some linguists. We avoid this phrase, preferring to reserve the term 'stop' for sounds in which there is a complete interruption of airflow.
All languages in the world have occlusives[1] and most have at least the voiceless stops pronounced as /[p]/, pronounced as /[t]/, pronounced as /[k]/ and the nasals pronounced as /[n]/, and pronounced as /[m]/. However, there are exceptions.
Colloquial Samoan lacks the coronals pronounced as /[t]/ and pronounced as /[n]/, and several North American languages, such as the northern Iroquoian languages, lack the labials pronounced as /[p]/ and pronounced as /[m]/. In fact, the labial plosive is the least stable of the voiceless stops in the languages of the world, as the unconditioned sound change pronounced as /[p]/ → pronounced as /[f]/ (→ pronounced as /[h]/ → Ø) is quite common in unrelated languages, having occurred in the history of Classical Japanese, Classical Arabic and Proto-Celtic, for instance.
Some of the Chimakuan, Salishan, and Wakashan languages near Puget Sound lack nasal occlusives pronounced as /[m]/ and pronounced as /[n]/, as does the Rotokas language of Papua New Guinea. In some African and South American languages, nasal occlusives occur only in the environment of nasal vowels and so are not distinctive.
Formal Samoan has nasals pronounced as //n ŋ// and pronounced as //t// but only one word with velar pronounced as /[k]/; colloquial Samoan conflates these to pronounced as //ŋ k//. Ni‘ihau Hawaiian has pronounced as /[t]/ for pronounced as //k// to a greater extent than Standard Hawaiian, but neither distinguishes a pronounced as //k// from a pronounced as //t//. It may be more accurate to say that Hawaiian and colloquial Samoan do not distinguish velar and coronal stops than to say they lack one or the other.
Yanyuwa distinguishes nasals and plosives in seven places of articulations /m n̪ n ṉ ɳ ŋ̟ ŋ̠/ and /b d̪ d ḏ ɖ ɡ̟ ɡ̠/ (it does not have voiceless plosives) which is the most out of all languages.[2]