ABRUPT RELEASE
Pulmonic egressive air is modified in the oral cavity to produce the phonemes of certain languages. In fact, there are three major types of air modifications: (a) complete blockage followed by sudden release, (b) complete blockage followed by gradual release, and (c) constriction or narrowing of the passage of air. The first results in the production of stops and plosives, the second in the production of affricates, and the last in the production of fricatives.
In systematic phonetics, the feature [±abrupt release] indicates whether the first of these types of air modifications is present in the articulation of a phoneme or not. In other words, when a phoneme is articulated by a complete blockage followed by a sudden release of the air in the oral cavity, that phoneme is [+abrupt release]. Otherwise, the phoneme is [-abrupt release]. Therefore, all stop consonants (including nasals /m/, /n/, /ŋ/, and plosives /p/, /b/, /t/, /d/, /k/, /g/) have the feature [+abrupt release].
Although nasal consonants are [+abrupt release], this feature is considered a redundant feature for them; therefore, it is not part of the inventory of features that are used to identify nasal consonants. In fact, the feature [+nasal] results in a [+abrupt release] phoneme. This is, like it was mentioned earlier, usually captured in a redundancy rule. Remember from preceding sections and chapters that a redundancy rule is a schematic representation (or a specific notation) that indicates a specific relationship between two entities. Redundancy rules usually go by the general format of
X ➙ Y
where X represents one of the entities and Y the other. In phonetics, for example, X stands for one phoneme or one phonetic feature, and Y for another phoneme or phonetic feature. The symbol (is read as "rewrites as." Take the following example:
This rule means that if a phoneme contains the feature [+nasal], it "automatically" contains the feature [+abrupt release]. Therefore, the feature [+abrupt release] does not need to be specifically mentioned in the bundle of features used to identify a [+nasal] phoneme. In fact, redundancy rules tell us how we can predict phoneme qualities and the basis of the qualities we have already identified.
Also notice that the features [abrupt release] and [continuant] are the opposite of each other. That is, when a phoneme is [+abrupt release], it will certainly be [-continuant]. This relationship, too, can be represented in the form of the following redundancy rule;
