In phonetics, a plosive, also known as an occlusive or simply a stop, is a pulmonic consonant in which the vocal tract is blocked so that all airflow ceases.
[4] Mute was sometimes used instead for voiceless consonants, whether plosives or fricatives, a usage that was later replaced with surd, from Latin surdus "deaf" or "silent",[5] a term still occasionally seen in the literature.
A plosive may lack an approach when it is preceded by a consonant that involves an occlusion at the same place of articulation, as in [d] in end or old.
In fact, the labial is the least stable of the voiceless plosives in the languages of the world, as the unconditioned sound change [p] → [f] (→ [h] → Ø) is quite common in unrelated languages, having occurred in the history of Classical Japanese, Classical Arabic, and Proto-Celtic, for instance.
It may be more accurate to say that Hawaiian and colloquial Samoan do not distinguish velar and coronal plosives than to say they lack one or the other.
In a prevocalic aspirated plosive (a plosive followed by a vowel or sonorant), the time when the vocal cords begin to vibrate will be delayed until the vocal folds come together enough for voicing to begin, and will usually start with breathy voicing.
Italian is well known for its geminate plosives, as the double t in the name Vittoria takes just as long to say as the ct does in English Victoria.
Japanese also prominently features geminate consonants, such as in the minimal pair 来た kita 'came' and 切った kitta 'cut'.
Estonian is unusual for contrasting three lengths, as in the minimal triplet kabi /kɑpi/ 'hoof', kapi /kɑpːi/ 'wardrobe [gen.
In such cases, the terms fortis is sometimes used for aspiration or gemination, whereas lenis is used for single, tenuous, or voiced plosives.
Simple nasals are differentiated from plosives only by a lowered velum that allows the air to escape through the nose during the occlusion.
Nasals are acoustically sonorants, as they have a non-turbulent airflow and are nearly always voiced, but they are articulatorily obstruents, as there is complete blockage of the oral cavity.
Swahili is well known for having words beginning with prenasalized stops, as in ndege 'bird', and in many languages of the South Pacific, such as Fijian, these are even spelled with single letters: b [mb], d [nd].
This could also be compared to the /dn/ cluster found in Russian and other Slavic languages, which can be seen in the name of the Dnieper River.
The terms prenasalization and postnasalization are normally used only in languages where these sounds are phonemic: that is, not analyzed into sequences of plosive plus nasal.
However, this is difficult to measure, and there is usually debate over the actual mechanism of alleged fortis or lenis consonants.
The indirect evidence for stiff voice is in the following vowels, which have a higher fundamental frequency than those following other plosives.
Many subclassifications of plosives are transcribed by adding a diacritic or modifier letter to the IPA symbols above.