Consonant parameters (continued)
Manners of articulation
Constriction degree
Place of articulation refers to where the narrowing occurs --
which active articulator gets close to which passive articulator.
Constriction degree refers to how close they get. The main
constriction degrees are:
- stop: the active articulator touches the passive
articulator and completely cuts off the airflow through the mouth.
English stops include: [p], [d], [k], [m].
- fricative: the active articulator doesn't touch the
passive articulator, but gets close enough that the airflow through the
opening becomes turbulent. English fricatives include [f], [
], [z].
- approximant: the active articulator approaches the
passive articulator, but doesn't even get close enough for the airflow to
become turbulent. English approximants include [j], [w], [
], and [l].
- affricate: Affricates can be seen as a sequence of a
stop and a fricative which have the same or similar places of
articulation. They are transcribed using the symbols for the stop and the
fricative. If one wants to emphasize the affricate as a "single" sound, a
tie symbol can be used to join the stop and the fricative (sometimes the
fricative is written as a superscript).
Notes:
- A stop cuts off airflow through the mouth.
Airflow through the nose does not matter -- you can have both oral and
nasal stops. Oral stops are often called plosives, including in
the IPA chart. Nasal stops are usually just call ed nasals.
- Approximants that are apical or laminal are often called
liquids (e.g., [], [l]). Approximants that correspond to vowels are often
called glides (e.g., [j] corresponds to [i], [w] to [u]).
- English has the affricates [t
] and [d
]. The stop and
the fricative halves of these affricates are at the same place of
articulation: the stop is in fact postalveolar rather than alveolar. We
could be explicit about this and underline the [t] and [d] (in IPA, a
minus sign under a symbol is a diacritic meaning "pronounced further back
in the mouth"), but most phoneticians believe this difference in the place
of articulation is so predictable that it doesn't have to be marked.
State of the glottis
For now, we can simply use the terms "voiced" and "voiceless" to answer
the question of what the vocal cords are doing:
- In voiced sounds, the vocal cords are vibrating.
- In voiceless sounds, the vocal cords are not vibrating.
Ultimately, we will see there are different ways of being voiced or
voiceless. The vocal cords can do a number of things. They can:
- be held so wide apart that the air makes no sound passing
through them. (This is nice when you have to breathe 24 hours a day, but
not as useful for speaking.)
- be held closer together, so that the air passing through them
becomes turbulent. This quality of sound is called breathiness.
It is what is happening in apsiration and in the sound [h].
- be held together so that the air passing through them causes
them to vibrate. This is called voicing.
- be held together so tightly that no air can pass through at
all, as in a glottal stop.
(By varying their tension and position, the vocal cords can also produce
many other effects like breathy voicing, creaky voicing, and falsetto.)
What the vocal cords are doing is independent of what the higher parts of
the vocal tract are doing. For any place of articulation and any degree
of stricture, you can get two different sounds: voiced and voiceless.
For example, [t] and [d] are formed identically in the mouth; the
difference is that the vocal cords vibrate during a [d] but not during a
[t]. (The obvious exception is the glottal place of articulation -- you
can't vibrate your vocal cords while making a glottal stop.)
In each cell of the IPA chart, the symbol for the voiceless sound is shown
to the left and that for the voiced sound to the right. Some rows only
have voiced symbols (e.g., nasals and approximants). You can write the
corresponding voiceless sound using the voiceless diacritic (a circle
under the voiced symbol).
Nasality
The soft palate can be lowered, allowing air to flow out through the nose,
or it can be raised to block nasal airflow. As was the case with the
vocal cords, what the soft palate is doing is independent the other
articulators. For almost any place of articulation, there are pairs of
stops that differ only in whether the soft palate is raised, as in the
oral stop [d], or lowered, as in the nasal stop [n].
Laterality
When you form an [l], your tongue tip touches your alveolar ridge (or
maybe your upper teeth) but it doesn't create a stop because one or both
sides of the tongue are lowered so that air can flow out along the side.
Sounds like this with airflow along the sides of the tongue are called
lateral, all others are called central (though we usually
just assume that a sound is central unless we explicitly say it's
lateral).
The side of the tongue can lower to different degrees. It can lower so
little that the air passing through becomes turbulent (giving a lateral
fricative like [
] or [
]) or it can lower enough for there to be no turbulence (a
lateral approximant). The [l] of English is a lateral approximant.
Airstream mechanism
Speech sounds need air to move. Most sounds (including all the sounds
of English) are created by modifying a stream of air that is pushed
outward from the lungs. But it's possible for the air to be set in
motion in other ways. Sounds which use one of the other three most
common airstream mechanisms are called ejectives, implosives,
and clicks. We'll discuss these possibilities later in the course.
Describing consonant segments
A consonant sound can be described completely by specifying each of the
parameters for place and manner of articulation. For example, [k] has the
following properties:
| active articulator | tongue body (dorsum) |
|
| passive articulator | soft palate (velum) |
|
| constriction degree | stop |
|
| state of glottis | voiceless |
|
| nasal | no |
|
| lateral | no |
|
| airstream mechanism | normal |
|
So [k] is a voiceless oral central dorso-velar stop.
Next: Consonant charts
Previous: Place of Articulation
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