Consonants

Consonants again

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:

active articulator: What part of the vocal tract moves in order to make the constriction?
(Usual answers: lips, tongue tip, tongue blade, tongue body, tongue root.)
passive articulator: What part of the vocal tract does the active articulator approach or touch?
(Usual answers: lips, upper teeth, alveolar ridge, postalveolar region, hard palate, soft palate, uvula, back pharyngeal wall.)
degree of constriction: How close do the active and passive articulators get to each other?
Usual answers: stop, fricative, approximant.
laterality: Does air flow around the side(s) of the tongue?

Questions about the entire sound (these apply to vowels as well as consonants):

nasality: Is air coming out through the nose?
laryngeal state: What are the vocal folds doing?
Usual answers: voiced, voiceless.
airstream mechanism: How does the air get moving for the sound?

Nasality

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.)

Laryngeal state

What are the vocal folds doing during the sound?

The two most common answers to this question are:

voiced: The vocal folds are vibrating.
voiceless: The vocal folds are not vibrating.

There are a number of different ways in which the vocal folds can vibrate -- and also ways in which they can fail to vibrate. For example, the vocal folds might be completely closed and not vibrating (as they are during a glottal stop), or they might be open, i.e., held apart and not vibrating, as they are for almost all other voicleless sounds.

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 "laryngeal state" 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:

breathy: as in whispering. There is a narrow opening at one end of the vocal folds that can cause the air passing through to become mildly turbulent.
creaky: extremely slow vibration.
falsetto

But breathiness and creakiness can be perfomed at the same time as ordinary (modal) voicing. 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.

Airstream mechanism

Any sound of human language involves modifying a stream of moving air. In almost all sounds of almost all languages, this moving airstream is creating by pushing air out from the lungs (technically, the pulmonic egressive airstream mechanism). All sounds of English (and the other common European languages) are pulmonic egressive.

But there are other possible ways of getting the air moving. Symbols for sounds which use one of the other airstream mechanisms can be found in the "Consonants (non-pulmonic)" sub-chart of the IPA chart.

Ejectives

Ejectives sounds are made using the ejective airstream mechanism. For example, an ejective [t'] is made by:

making an alveolar closure and closing the vocal folds. (This traps the air between the two closures.)
raising the larynx in the throat. (Since the larynx houses the vocal folds, which are closed throughout the ejective sound, this causes the trapped air to occupy less volume and raises its pressure.)
releasing the alveolar closure. (The pressurized trapped air rushes out much more forcefully than in a normal [t].)

Because the vocal folds are closed throughout, ejectives are always voiceless. (For similar reasons, ejectives can never be nasal.)

Implosives

Implosives are voiced oral stops, but with a different method of causing the voicing that involves lowering the larynx in the throat, pulling the vocal folds across the air, in addition to (or instead of) pushing the air across the vocal folds.

Clicks

Clicks are formed by:

forming a velar closure and a second closure further forward in the mouth (with the tongue tip/blade or the lips), trapping air between the two closures;
enlarging the space between the two closures (by lowering the centre of the tongue or lowering the jaw). The trapped air has to spread out over a wider volume, creating a partial vacuum;
releasing the forward closure -- air outside will come rushing in to fill the partial vacuum, creating a sharp, clicking sound.

The only languages in the world that use clicks as regular consonants are the languages of the Kalahari Desert in south-west Africa and the neighbouring Bantu languages, like Zulu and Xhosa.

Active articulator

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:

lip	labial
tongue tip	apical
tongue blade	laminal
tongue body	dorsal
tongue blade	radical

Passive articulator

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:

Passive articulator	Adjective	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
uvula	uvular	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.

Constriction degree

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:

affricates: plosives followed by fricatives at the same place of articulation.
taps: stops lasting for a very short duration.
trills: sounds where one of the articulators vibrates against the other (resulting in a fast alternation of blocked and unblocked airflow).
A trilled [r] is common in many languages. Most dialects of French pronounce r with a uvular trill [R] -- where the uvula vibrates against the tongue body. Bilabial trills are also found in a small number of languages.

Laterality

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.

Next: Reading the IPA consonant chart, Up: Table of contents