Let's look at consonants again in more detail -- this time covering all the distinctions that can make different consonants in all languages, not just English.
In order to fully describe a consonant, we need to be able to answer seven questions about it. Three of these questions apply to the entire consonant sound; four of them have to be answered for each constriction (each place where the vocal tract narrows).
Questions about each constriction:
The active articulator is the part of the vocal tract that moves in order to form a constriction. The usual active articulators, together with their Latinate adjectives, are:
The passive articulator is the part of the vocal tract that the active articulator comes closest to in forming the constriction. (Since most of the active articulators are parts of the tongue, most of the passive articulators are parts of the roof of the mouth.)
The following table shows the passive articulators, their Latinate terms, and the active articulators that they are normally paired with:
Usual active articulator(s)
|lip||labial||the other lip|
|upper teeth||dental||lower lip, tongue blade, tongue tip|
|alveolar ridge||alveolar||tongue tip, tongue blade|
|postalveolar region||postalveolar||tongue blade, tongue tip|
|hard palate||palatal||tongue body (sometimes tongue tip)|
|soft palate||velar||tongue body|
|pharyngeal wall||pharyngeal||tongue root|
The active and the passive articulator together define the constriction's place of articulation. It is common to express the combination by joining the active articulator's adjective (ending in "-o") with the passive articulator's adjective. E.g., a "labio-dental" is a sound involving the (lower) lip as the active articulator and the (upper) teeth as the passive articulator. A "dorso-velar" is a sound involving the tongue body as the active articulator and the soft palate as the passive articulator.
The three most common degrees of constriction are stop, fricative, and approximant.
In addition, there are some other consonant properties that can be thought of as complex constriction degrees:
In a lateral constriction, the centre of the active articulator contacts the passive articulator, but one side of the active articulator is lowered so that air can flow around the side of it. Sounds like this are called laterals. All other sounds (and that's almost all of them) are sometimes called central -- but don't confuse this with central vowels (that fall between front and back).
Depending on how big the opening is at the side of the active articulator, a lateral can be either an approximant or a fricative. The [l] of English is a lateral approximant.
Does air escape through the nose during the sound? For nasal sounds, the answer is yes. For oral sounds, the answer is no.
(Consonants can also be pre-nasalized or post-nasalized if the nasality changes during the course of the consonant.)
What are the vocal folds doing during the sound?
The two most common answers to this question are:
Recall that there are a variety of possible timing relationships between when the main constriction of a consonant happens and when voicing starts (see the section on Voice Onset Time). "Voiced" and "voiceless" are usually just cover terms for a language's choice of which points along the VOT continuum to use. (So, the answer to the phonation question is also a convenient place to mention if the consonant is aspirated.)
Some other possible states for the vocal folds are not by themselves terribly useful for language:
But breathiness and creakiness can be perfomed at the same time as ordinary (modal) voicing, resulting in breathy voice and creaky voice. These combinations do have linguistic uses. In many languages, a [ba] pronounced with breathy voicing can have a different meaning from a [ba] pronounced with modal voicing. Similarly, a [ba] pronounced with creaky voicing might mean something different from a [ba] pronounced with modal voicing.