In phonetics, the airstream mechanism is the method by which airflow is
created in the vocal tract. Along with phonation and articulation, it is one of
three main components of speech production. The airstream mechanism is
mandatory for sound production and constitutes the first part of this process,
which is called initiation.
The organ generating the airstream is called the initiator and there are three
initiators used in spoken human languages:
the diaphragm together with the ribs and lungs (pulmonic mechanisms),
the glottis (glottalic mechanisms), and
the tongue (lingual or "velaric" mechanisms).
Though not used in any language, the cheeks may be used to generate the
airstream (buccal mechanism, notated { } in VoQS). See buccal speech.
After a laryngectomy, the esophagus may be used as the initiator (notated {}
for simple esophageal speech and {} for tracheo-esophageal speech in
VoQS). See esophageal speech.
Percussive consonants are produced without any airstream mechanism.[1]
Contents
1 Types of airstream mechanism
2 Pulmonic initiation
3 Glottalic initiation
4 Lingual (velaric) initiation
5 Airstream contours
6 Percussive consonants
7 See also
8 References
9 External links
Types of airstream mechanism
Any of the three initiators diaphragm, glottis or tongue may act by either
increasing or decreasing the pressure generating the airstream. These changes
in pressure often correspond to outward and inward airflow, and are therefore
termed egressive and ingressive.
Of these six resulting airstream mechanisms, four are found lexically around
the world:
pulmonic egressive, where the air is pushed out of the lungs by the ribs
and diaphragm. All human languages employ such sounds (such as
vowels), and nearly three out of four use them exclusively.
glottalic egressive, where the air column is compressed as the glottis
moves upward. Such consonants are called ejectives. Ejective and
ejective-like consonants occur in 16% of the languages.
glottalic ingressive, where the air column is rarefied as the glottis moves
downward. Such consonants are called implosives. Implosive and
implosive-like consonants occur in 13% of the world's languages. Despite
the name, the airstream may not actually flow inward: While the glottis
moves downward, pulmonic air passes outward through it, but the
reduction in pressure makes an audible difference to the sound.
lingual ingressive, AKA velaric ingressive, where the air in the mouth is
rarefied by a downward movement of the tongue. These are the click
consonants. Clicks are regular sounds in ordinary words in fewer than 2%
of the world's languages, all in Africa.[2]
These mechanisms may be combined into airstream contours, such as clicks
which release into ejectives.
The Khoisan languages have pulmonic, ejective, and click consonants, the
Chadic languages have pulmonic, implosive, and ejective consonants, and the
Nguni languages utilize all four, pulmonic, click, implosive, and ejective, in
normal vocabulary. Most other languages utilize only one or two airstream
mechanisms.
In interjections, the other two mechanisms may be employed. For example, in
countries as diverse as Sweden, Turkey, and Togo, a pulmonic ingressive
("gasped" or "inhaled") vowel is used for back-channeling or to express
agreement, and in France a lingual egressive (a "spurt") is used to express
dismissal. The only language where such sounds are known to be contrastive in
normal vocabulary is the extinct ritual language Damin (also the only language
outside Africa with clicks); however, Damin appears to have been intentionally
designed to differ from normal speech.
Pulmonic initiation
Initiation by means of the lungs (actually the diaphragm and ribs) is called
pulmonic initiation. The vast majority of sounds used in human languages are
pulmonic egressives. In most languages, including all the languages of Europe
(excluding the Caucasus), all phonemes are pulmonic egressives.
The only attested use of a phonemic pulmonic ingressive is a lateral fricative in
Damin, a ritual language formerly used by speakers of Lardil in Australia. This
can be written with the extended version of the International Phonetic
Alphabet as []. !X has ingression as a phonetic detail in one series of its
clicks, which are ingressive voiceless nasals with delayed aspiration, [
! ]. Peter Ladefoged considers these to be among the
most difficult sounds in the world. Other languages, for example in Taiwan,
have been claimed to have pulmonic ingressives, but these claims have either
proven to be spurious or to be occasional phonetic detail.
In interjections, but not in normal words, pulmonic ingressive vowels or words
occur on all continents.[3] This is commonly done for back-channeling (as with
[] in Ewe) or affirmation (as with [] in Swedish). In English, an audible
intake of breath, [h], or an indrawn consonant such as [t] or [pt] is
used in a conversation to indicate that someone is about to speak or is
preparing to continue speaking.[4] In some languages, such as Finnish and
Amharic, entire phrases may be uttered with an ingressive airstream. (See
ingressive sound.)
Glottalic initiation
It is possible to initiate airflow in the upper vocal tract by means of the vocal
cords or glottis. This is known as glottalic initiation.
For egressive glottalic initiation, one lowers the glottis (as if to sing a low note),
closes it as for a glottal stop, and then raises it, building up pressure in the oral
cavity and upper trachea. Glottalic egressives are called ejectives. The glottis
must be fully closed to form glottalic egressives, or the air column would flow
backwards over it; it is therefore impossible to pronounce voiced ejectives.
Ejective allophones of voiceless stops occur in many varieties of English at the
ends of intonation units.[5]
For ingressive glottalic initiation, the sequence of actions performed in glottalic
pressure initiation is reversed: one raises the glottis (as if to sing a high note),
closes it, and then lowers it to create suction in the upper trachea and oral
cavity. Glottalic ingressives are called implosives, although they may involve
zero airflow rather than actual inflow. Because the air column would flow
forwards over the descending glottis, it is not necessary to fully close it, and
implosives may be voiced; indeed, voiceless implosives are exceedingly rare.
It is usual for implosives to be voiced. Instead of keeping the glottis tightly
closed, it is tensed but left slightly open to allow a thin stream of air through.
Unlike pulmonic voiced sounds, in which a stream of air passes through a
usually-fixed glottis, in voiced implosives a mobile glottis passes over a nearly
motionless air column to cause vibration of the vocal cords. Phonations that
are more open than modal voice, such as breathy voice, are not conducive to
glottalic sounds because in these the glottis is held relatively open, allowing air
to readily flow through and preventing a significant pressure difference from
building up behind the articulator.
Because the oral cavity is so much smaller than the lungs, vowels and
approximants cannot be pronounced with glottalic initiation. So-called
glottalized vowels and other sonorants use the more common pulmonic
egressive airstream mechanism.
There is no clear divide between pulmonic and glottalic sounds. Some
languages may have consonants which are intermediate. For example,
glottalized consonants in London English, such as the t in rat [t], may be
weakly ejective. Similarly, fully voiced stops in languages such as Thai, Zulu,
and Maidu are weakly implosive. This ambiguity does not occur with the next
airstream mechanism, lingual, which is clearly distinct from pulmonic sounds.[6]
Lingual (velaric) initiation
The third form of initiation in human language is lingual or velaric initiation,
where a sound is produced by a closure at two places of articulation, and the
airstream is formed by movement of the body of the tongue. Lingual stops are
more commonly known as clicks, and are almost universally ingressive. The
word lingual is derived from Latin lingua, which means tongue.
To produce a lingual ingressive airstream, first close the vocal tract at two
places: at the back of the tongue, as in a velar or uvular stop, and
simultaneously with the front of the tongue or the lips, as in a coronal or
bilabial stop. These holds may be voiced or nasalized. Then lower the body of
the tongue to rarefy the air above it. The closure at the front of the tongue is
opened first, as the click "release"; then the closure at the back is released for
the pulmonic or glottalic click "accompaniment" or "efflux". This may be
aspirated, affricated, or even ejective. Even when not ejective, it is not
uncommon for the glottis to be closed as well, for a triply articulated
consonant, and this third closure is released last to produce a glottalized click.
Clicks are found in very few languages, notably the Khoisan languages of
southern Africa and some nearby tongues such as Zulu. They are more often
found in extra-linguistic contexts, such as the "tsk tsk" sound many Westerners
use to express regret or pity (a dental click), or the clucking noise used by many
equestrians to urge on their horses (a lateral click).
Lingual egressive initiation is performed by reversing the sequence of a lingual
ingressive: the front and back of the tongue (or lips and back of the tongue)
seal off the vocal cavity, and the cheeks and middle of the tongue move inward
and upward to increase oral pressure. The only attested use of a lingual
egressive is a bilabial nasal egressive click in Damin. Transcribing this also
requires the use of the Extended IPA, [].
Since the air pocket used to initiate lingual consonants is so small, it is not
thought to be possible to produce lingual fricatives,[citation needed] vowels, or other
sounds which require continuous airflow.
Clicks may be voiced, but they are more easily nasalized. This may be because
the vocal cavity behind the rearmost closure, behind which the air passing
through the glottis for voicing must be contained, is so small that clicks cannot
be voiced for long. Allowing the airstream to pass through the nose enables a
longer production.
Nasal clicks involve a combination of lingual and pulmonic mechanisms. The
velum is lowered so as to direct pulmonic airflow through the nasal cavity
during the lingual initiation. This nasal airflow may itself be egressive or
ingressive, independently of the lingual initiation of the click. Nasal clicks may
be voiced, but are very commonly unvoiced and even aspirated, which is rare
for purely pulmonic nasals.
Airstream contours
In some treatments, complex clicks are posited to have airstream contours, in
which the airstream changes between the front (click) and rear (non-click)
release. There are two attested types: Linguo-pulmonic consonants, where the
rear release is a uvular obstruent such as [q] or []; and linguo-glottalic
consonants, where the rear release is an ejective such as [q] or [q].
Theoretically, a release into an implosive should be possible, but both clicks
and dorsal implosives ([, ]) are rare (the latter because they are difficult to
pronounce), and no language is known to combine them.
Percussive consonants
Consonants may be pronounced without any airstream mechanism. These are
percussive consonants, where the sound is generated by one organ striking
another. Percussive consonants are not phonemic in any known language,
though the extensions to the IPA for disordered speech provide symbols for a
bilabial percussive [] (smacking lips) and a bidental percussive [] (gnashing
teeth). The only percussive known to be used in nondisordered speech is a
sublingual percussive [] (a tongue slap) that appears allophonically in the
release of alveolar clicks in the Sandawe language of Tanzania.
In phonetics, the airstream mechanism is the method by which airflow is
created in the vocal tract. Along with phonation and articulation, it is one of
three main components of speech production. The airstream mechanism is
mandatory for sound production and constitutes the first part of this process,
which is called initiation.
The organ generating the airstream is called the initiator and there are three
initiators used in spoken human languages:
the diaphragm together with the ribs and lungs (pulmonic mechanisms),
the glottis (glottalic mechanisms), and
the tongue (lingual or "velaric" mechanisms).
Though not used in any language, the cheeks may be used to generate the
airstream (buccal mechanism, notated { } in VoQS). See buccal speech.
After a laryngectomy, the esophagus may be used as the initiator (notated {}
for simple esophageal speech and {} for tracheo-esophageal speech in
VoQS). See esophageal speech.
Percussive consonants are produced without any airstream mechanism.[1]
Contents
1 Types of airstream mechanism
2 Pulmonic initiation
3 Glottalic initiation
4 Lingual (velaric) initiation
5 Airstream contours
6 Percussive consonants
7 See also
8 References
9 External links
Types of airstream mechanism
Any of the three initiators diaphragm, glottis or tongue may act by either
increasing or decreasing the pressure generating the airstream. These changes
in pressure often correspond to outward and inward airflow, and are therefore
termed egressive and ingressive.
Of these six resulting airstream mechanisms, four are found lexically around
the world:
pulmonic egressive, where the air is pushed out of the lungs by the ribs
and diaphragm. All human languages employ such sounds (such as
vowels), and nearly three out of four use them exclusively.
glottalic egressive, where the air column is compressed as the glottis
moves upward. Such consonants are called ejectives. Ejective and
ejective-like consonants occur in 16% of the languages.
glottalic ingressive, where the air column is rarefied as the glottis moves
downward. Such consonants are called implosives. Implosive and
implosive-like consonants occur in 13% of the world's languages. Despite
the name, the airstream may not actually flow inward: While the glottis
moves downward, pulmonic air passes outward through it, but the
reduction in pressure makes an audible difference to the sound.
lingual ingressive, AKA velaric ingressive, where the air in the mouth is
rarefied by a downward movement of the tongue. These are the click
consonants. Clicks are regular sounds in ordinary words in fewer than 2%
of the world's languages, all in Africa.[2]
These mechanisms may be combined into airstream contours, such as clicks
which release into ejectives.
The Khoisan languages have pulmonic, ejective, and click consonants, the
Chadic languages have pulmonic, implosive, and ejective consonants, and the
Nguni languages utilize all four, pulmonic, click, implosive, and ejective, in
normal vocabulary. Most other languages utilize only one or two airstream
mechanisms.
In interjections, the other two mechanisms may be employed. For example, in
countries as diverse as Sweden, Turkey, and Togo, a pulmonic ingressive
("gasped" or "inhaled") vowel is used for back-channeling or to express
agreement, and in France a lingual egressive (a "spurt") is used to express
dismissal. The only language where such sounds are known to be contrastive in
normal vocabulary is the extinct ritual language Damin (also the only language
outside Africa with clicks); however, Damin appears to have been intentionally
designed to differ from normal speech.
Pulmonic initiation
Initiation by means of the lungs (actually the diaphragm and ribs) is called
pulmonic initiation. The vast majority of sounds used in human languages are
pulmonic egressives. In most languages, including all the languages of Europe
(excluding the Caucasus), all phonemes are pulmonic egressives.
The only attested use of a phonemic pulmonic ingressive is a lateral fricative in
Damin, a ritual language formerly used by speakers of Lardil in Australia. This
can be written with the extended version of the International Phonetic
Alphabet as []. !X has ingression as a phonetic detail in one series of its
clicks, which are ingressive voiceless nasals with delayed aspiration, [
! ]. Peter Ladefoged considers these to be among the
most difficult sounds in the world. Other languages, for example in Taiwan,
have been claimed to have pulmonic ingressives, but these claims have either
proven to be spurious or to be occasional phonetic detail.
In interjections, but not in normal words, pulmonic ingressive vowels or words
occur on all continents.[3] This is commonly done for back-channeling (as with
[] in Ewe) or affirmation (as with [] in Swedish). In English, an audible
intake of breath, [h], or an indrawn consonant such as [t] or [pt] is
used in a conversation to indicate that someone is about to speak or is
preparing to continue speaking.[4] In some languages, such as Finnish and
Amharic, entire phrases may be uttered with an ingressive airstream. (See
ingressive sound.)
Glottalic initiation
It is possible to initiate airflow in the upper vocal tract by means of the vocal
cords or glottis. This is known as glottalic initiation.
For egressive glottalic initiation, one lowers the glottis (as if to sing a low note),
closes it as for a glottal stop, and then raises it, building up pressure in the oral
cavity and upper trachea. Glottalic egressives are called ejectives. The glottis
must be fully closed to form glottalic egressives, or the air column would flow
backwards over it; it is therefore impossible to pronounce voiced ejectives.
Ejective allophones of voiceless stops occur in many varieties of English at the
ends of intonation units.[5]
For ingressive glottalic initiation, the sequence of actions performed in glottalic
pressure initiation is reversed: one raises the glottis (as if to sing a high note),
closes it, and then lowers it to create suction in the upper trachea and oral
cavity. Glottalic ingressives are called implosives, although they may involve
zero airflow rather than actual inflow. Because the air column would flow
forwards over the descending glottis, it is not necessary to fully close it, and
implosives may be voiced; indeed, voiceless implosives are exceedingly rare.
It is usual for implosives to be voiced. Instead of keeping the glottis tightly
closed, it is tensed but left slightly open to allow a thin stream of air through.
Unlike pulmonic voiced sounds, in which a stream of air passes through a
usually-fixed glottis, in voiced implosives a mobile glottis passes over a nearly
motionless air column to cause vibration of the vocal cords. Phonations that
are more open than modal voice, such as breathy voice, are not conducive to
glottalic sounds because in these the glottis is held relatively open, allowing air
to readily flow through and preventing a significant pressure difference from
building up behind the articulator.
Because the oral cavity is so much smaller than the lungs, vowels and
approximants cannot be pronounced with glottalic initiation. So-called
glottalized vowels and other sonorants use the more common pulmonic
egressive airstream mechanism.
There is no clear divide between pulmonic and glottalic sounds. Some
languages may have consonants which are intermediate. For example,
glottalized consonants in London English, such as the t in rat [t], may be
weakly ejective. Similarly, fully voiced stops in languages such as Thai, Zulu,
and Maidu are weakly implosive. This ambiguity does not occur with the next
airstream mechanism, lingual, which is clearly distinct from pulmonic sounds.[6]
Lingual (velaric) initiation
The third form of initiation in human language is lingual or velaric initiation,
where a sound is produced by a closure at two places of articulation, and the
airstream is formed by movement of the body of the tongue. Lingual stops are
more commonly known as clicks, and are almost universally ingressive. The
word lingual is derived from Latin lingua, which means tongue.
To produce a lingual ingressive airstream, first close the vocal tract at two
places: at the back of the tongue, as in a velar or uvular stop, and
simultaneously with the front of the tongue or the lips, as in a coronal or
bilabial stop. These holds may be voiced or nasalized. Then lower the body of
the tongue to rarefy the air above it. The closure at the front of the tongue is
opened first, as the click "release"; then the closure at the back is released for
the pulmonic or glottalic click "accompaniment" or "efflux". This may be
aspirated, affricated, or even ejective. Even when not ejective, it is not
uncommon for the glottis to be closed as well, for a triply articulated
consonant, and this third closure is released last to produce a glottalized click.
Clicks are found in very few languages, notably the Khoisan languages of
southern Africa and some nearby tongues such as Zulu. They are more often
found in extra-linguistic contexts, such as the "tsk tsk" sound many Westerners
use to express regret or pity (a dental click), or the clucking noise used by many
equestrians to urge on their horses (a lateral click).
Lingual egressive initiation is performed by reversing the sequence of a lingual
ingressive: the front and back of the tongue (or lips and back of the tongue)
seal off the vocal cavity, and the cheeks and middle of the tongue move inward
and upward to increase oral pressure. The only attested use of a lingual
egressive is a bilabial nasal egressive click in Damin. Transcribing this also
requires the use of the Extended IPA, [].
Since the air pocket used to initiate lingual consonants is so small, it is not
thought to be possible to produce lingual fricatives,[citation needed] vowels, or other
sounds which require continuous airflow.
Clicks may be voiced, but they are more easily nasalized. This may be because
the vocal cavity behind the rearmost closure, behind which the air passing
through the glottis for voicing must be contained, is so small that clicks cannot
be voiced for long. Allowing the airstream to pass through the nose enables a
longer production.
Nasal clicks involve a combination of lingual and pulmonic mechanisms. The
velum is lowered so as to direct pulmonic airflow through the nasal cavity
during the lingual initiation. This nasal airflow may itself be egressive or
ingressive, independently of the lingual initiation of the click. Nasal clicks may
be voiced, but are very commonly unvoiced and even aspirated, which is rare
for purely pulmonic nasals.
Airstream contours
In some treatments, complex clicks are posited to have airstream contours, in
which the airstream changes between the front (click) and rear (non-click)
release. There are two attested types: Linguo-pulmonic consonants, where the
rear release is a uvular obstruent such as [q] or []; and linguo-glottalic
consonants, where the rear release is an ejective such as [q] or [q].
Theoretically, a release into an implosive should be possible, but both clicks
and dorsal implosives ([, ]) are rare (the latter because they are difficult to
pronounce), and no language is known to combine them.
Percussive consonants
Consonants may be pronounced without any airstream mechanism. These are
percussive consonants, where the sound is generated by one organ striking
another. Percussive consonants are not phonemic in any known language,
though the extensions to the IPA for disordered speech provide symbols for a
bilabial percussive [] (smacking lips) and a bidental percussive [] (gnashing
teeth). The only percussive known to be used in nondisordered speech is a
sublingual percussive [] (a tongue slap) that appears allophonically in the
release of alveolar clicks in the Sandawe language of Tanzania.
