The Expressive Transducer, and What Babies Hear
. In Mysak's model, we described the Expressive Transducer in three parts: the Motor, the Generator and the Modulators.
. Motor: This refers to the source of energy for speech, and if anything is going to happen muscles must be involved. Nowhere is this more true than for the speech act.
. The first muscle we may all think of is the diaphragm. Actually, this is a domed shaped muscle when relaxed.
. It separates the chest cavity from the abdominal cavity. When it is tensed, it flattens out, creating a partial vacuum in the chest cavity. Air will rush in through the nose, trachea ("wind pipe") and lungs to fill the space.
. This is inhalation and as you can see it is an active process. There are many more muscles involved, however, in inhalation than just the diaphragm.
When breathing for life, inhalation is active involving many muscles and exhalation is passive.
. There are muscles between the ribs, and over the shoulders, some extending from the back of the head.
. When the diaphragm flattens, these muscles combine to expand the ribcage. Even muscles low down in the back may be called upon to stabilize the spinal column.
. Think of the massive timing process that the brain must habitually orchestrate to repeatedly coordinate all these muscles.
. In contrast to inhalation which is so active and complicated, exhalation is the easiest thing we ever do (unless we have emphysema).
. To breath out we simply relax and the elastic nature of the diaphragm returns it to its normal dome shape (helped by the push of the viscera which were compressed during inhalation). The chest cavity collapses helped by gravity. All this forces the air out. It is a totally passive process.
When breathing for speech, exhalation is highly controlled, requiring special neurological circuitry which humans posses.
. But when breathing for the purpose of speech, the exhalation process also becomes active and even more complicated. Now the breath is forced out through the vocal folds in a carefully controlled flow.
. We do this effortlessly, partly because we have a large cadre of nerves devoted to the process. This is a genetic inheritance. "Ed" the "talking horse" and even "Koko" the signing gorilla could not really control the breath stream well enough to produce speech as humans do.
. If you are not familiar with "Ed" check the notes.
. Sometimes the process is pathologically disturbed. Cerebral Palsy children may have problems in coordinating the flow of speech and may find it difficult to get more than one word or sentence to a breath if at all.
. Even some stutterers find the processes disrupted and the lack of coordination in breathing process is quite visible if not uncomfortable to watch.
NOTES: More than you would want to know about breath control.
NOTES: And still more on breath control.
The Generator is a mechanism to produce sound , which is required for speech.
. The purpose of respiration for speech, is to move air. Of course there are other muscles not involved with moving air which must nevertheless be coordinated with the breath stream.
. These are the muscles of the soft palate (velum), the tongue, lips jaw, and the larynx. The function of the larynx, of course, is to generate the sounds for the vowels and many consonants.
. Generator: The whole purpose of moving air is to create sound which can transmit a symbolic signal. There are a number of locations around the body, and particularly in the oral track were sounds can be made. Tapping with the feet is one example. "Donald Duck" talk using the back of the oral cavity is another. Using the feet takes considerable energy, and it's hard to find a time when the feet are not precoccupied with walking or standing.
NOTES: Alternate forms of ORAL communication.
OR
"Donald Duck" talk is very limited in its
range of pitch and loudness, and constricts the tongue in its production.
NOTES: More information
on the Larynx. NOTES:
Some more information on the Vocal Folds. NOTES:
Information about vocal nodules in teenagers. NOTES:
Vocal nodules in singers. NOTES: More than you
really want to know about vocal nodules. NOTES: See some of the
benefits of smoking. It will steal your breath away. NOTES: Visit
some folks who have experienced this. NOTES: Here is some information
on QB VII. NOTES: Here is some more
information on Jack Hawkins, who played the Judge in QB VII. NOTES: Here is some information
on the artificial larynx. NOTES: Another example of an artificial larynx. NOTES: Still more information on the
artificial larynx. NOTES: Hear samples of esophogeal speech and an
artificial larynx. NOTES:
Want to hear some outstanding resonance? NOTES:
Some information on improvoving nasality if you want to spend big bucks. .
Place of
Articulation. The hallmark of a consonant is the constriction of the
airflow somewhere on the vocal tract. This constriction creates a noise, as we
discussed earlier. o
There is another one
in Hebrew, which I wont even attempt to explain but it sounds to me like
"Hkghshghghksh." I believe I did make that sound correctly by
serendipity once during a heated discussion with my wife who was choking me at
the time. o
The baby, of course,
is capable of hearing all these boundaries, but in time will retain only those
that are used in his/her presence. o
In terms of sound
production, the baby during the initial reflexive stages, of cooing and
babbling, when there is little control of the articulators, will produce mainly
the back consonants like "K," and "G." o
This is not
surprising since tongue tip control is not gained until later. Plus, the tongue
is relatively large for the size of the oral cavity. o
At about six months
of age, however, considerable voluntary control of the articulators is
achieved. o
The child enters a
new stage of vocalization called Lalling, which we will discuss later in another
section. Under these circumstances the sounds we hear at first almost
exclusively are the front consonants like "M," "B," and
"D." o
It is not surprising
that the names of significant others to the baby in many languages are words
that begin with front consonants, like "Mama," Dada," and
"Baba." o
For Fricatives,
the constriction is only partial, thus creating some pressure build-up while at
the same time letting air escape with a turbulence that creates a noise (e.g.,
"F," "TH," "S," and "Sh.") o
An Affricate
is a phonemic "sandwich," that it is produced by both of the
distinctive features, one top of the other. There are only two in English so we
will use them as examples. The first is the first (or last) sound in the word
"church." o
This starts out as
the plosive "D" and ends up as the fricative "Zsh" as in
the word "vision." .
Voicing:
Sometimes both the point of constriction for two or more phonemes and the
manner are the same! What differs is whether or not a larngeal tone accompanies
the air turbulence. The only difference between "P" and
"B," for example, is that the latter includes a tone from the larynx.
These pairs of sounds are called cognates. o
Put your hand on your
larynx and say "P" and "B" several times in succession. You
can feel the vibration of the larynx on the "B" sound. Which one of
the pairs of following cognates are voiced (have +Voicing): o
P B o
D T o
F V o
S Z o
G K o
Which of the two
affricates that we discussed has +voicing? .
Nasality:
Unlike French which includes nasal resonance in some vowels, no vowels in
English include it. No consonants can be made either nasality with the
exception these three: "M," "N," and "Ng." .
There are many more
distinctive features for consonants, but we'll leave these for all those
linguistically brilliant babies to discover, and for those few lifeless speech
pathologists or linguists to describe in a book. .
The Place of
Articulation: This sounds suspiciously like a feature that we discussed earlier
for consonants. But vowels don't involve the constriction of vocal air flow. In
this case, place of articulation is referring to the contour of the tongue. o
The tongue is capable
of arching in different ways to partition the air masses in the oral cavity. o
The vowels that are
produced when the tongue arches toward the front are called front vowels. An
example would be the vowel in the word: .
"beat." o
When the tongue
arches toward the center, we have mid vowels produced, such as in the word: .
"up." o
This makes some
logical sense since the back of the tongue would occupied in the act of
constricting the air flow for the consonants. o
Later as the child gains
control over the articulators and voluntarily produces sounds, the back vowels
will be heard initially more frequently. This is quite prevalent in early words
like "Mama," and "Papa." .
The height of
articulation: Not only does the tongue partition the air masses to produce
front and back vowels, but it can be raised or lowered in the oral cavity to
further modify them. o
Thus a full array of
front vowels can be produced from high to low as follows: .
"beat" .
"bit" .
"bait" .
"bet" .
"bat" o
For the back vowels,
the array would be from high to low as follows: .
"soon" .
"stood" .
"sow' .
"saw" .
"sod" o
Although it is not absolutely
necessary, most people drop their jaw when producing low vowels to provide more
room for the tongue. This has considerable value in the process of speech (lip)
reading. o
In lip reading the
viewer has no way of knowing what the tongue is doing (because it is not
visible). Hence, the only way that he/she can discriminate between words like
"beat" and "bat" is to deduce the sound by observing the
movement of the jaw. o
I might add that
Speech reading is not just for the deaf or hard of hearing. o
We all use it when we
are listening in a noisy environment and can(tm)t clearly hear the speech
sounds. o
Then our gaze will
subtly shift (often, without our even realizing it) from focusing on the
speaker's eyes to observing his/her mouth. o
Ironically, in these
situations, our "hearing" seems to gets worse if the lights are
dimmed. .
Tense versus Lax:
A very subtle distinctive feature is the degree of tenseness exhibited by the
tongue when producing certain vowels. o
Both the highest
front and back vowels, for example, are Tense. Some real examples are: .
"Lean"
(front) & "Luke" (back). o
The next lower vowels
are less tense or Lax. Examples are: .
"Lynn"
(front) and "Look" (back). o
The mid vowel also,
as in "up" is also Lax. o
This is nothing as
adults that we can readily feel or see. The muscle tension is orchestrated at a
subliminal level during production. .
Lip Rounding:
Take a class in speech improvement and you will spend a lot of time practicing
to round the lips when producing certain vowels. o
Paradoxically, if you
take a class in Ventriloquism, you will spend a lot of time practicing NOT to
round the lips for the same sounds! How come? o
Lip rounding is not
essential for the production of any of the vowels. But it does have a place in
vowel production. o
In English, there is
a general tendency to round the lips for the back vowels. Try it and see... .
"soon" .
"stood" .
"sow" .
"saw" .
"sod" o
Alternately, we
relatively draw the lips back for the front vowels. Try that too: .
"beat" .
"bit" .
"bait" .
"bet" .
"bat" o
Now for a fun experience
say the back vowels (starting with "soon,") but make your lips draw
back, as in a broad smile. It feels funny but with a little practice, you can
do it. Try the front vowels above (starting with "beat") but purse
your lips forward (i.e.,round your lips). o
Where lip movements
become really important is in the process of lip reading, which as I said, we
all do. In a noisy environment we can tell from the lips whether the person
said "beat" or "boot." If he rounded the lips, we know he
said "boot." o
And if he rounded the
lips and dropped the jaw simultaneously, he probably said something like
"bought." o
Now, what happens if
he says the word "bought" but doesn(tm)t purse the lips or drop the
jaw? o
The word comes out
fine but it is definitely difficult to lip read. o
If he says the word
with no lip or jaw movement and at the same time vividly manipulates the mouth
of a puppet, the movement will draw our attention visually. o
We will perceive the
puppet to be doing the talking. We have just experienced ventriloquists.
Notice, that he did not "throw" his voice as many people believe. NOTES: Some
information on Speech Reading. .
Ventriloquism is not
"throwing" the voice. It is, not moving the lips or the jaw. Even the
consonants that require the front-most constriction can be accomplished by the
tongue with some practice and will sound just fine. These are just a few of the distinctive
features (building blocks of phonemes) that the baby is equipped to hear at
birth. Now we are
ready to look at the Receptive Transducer for the Auditory Modality- the Ear
and see how is interfaces with sound to make speech and language possible, or
how it fails to interface and how this impacts on speech and language. .
Ironically, our generator, which is very effective and
efficient comes to us perhaps through serendipity as a side effect of nature's
attempt to solve a serious structural problem.
.
Visualize this. Here we have the oral cavity which is
used for two purposes: Food intake and Air Intake.
.
The structural problem is this."They" placed
our air intake tube (the trachea) in front of the foot intake tube (the
esophagus). That means that every time you take a bite to eat, you must pass
the food over the trachea.
.
Should a tiny morsel (like a sliced carrot or even a
vitamin pill) fall into the trachea, we may have just five more minutes to
live--and not a particularly fun five minutes either!
If liquid or food gets down the wrong tube (the Trachea) we may get
pneumonia or worse yet, quick asphyxiation.
.
And even if it's liquid, you might not choke but you
then become a good candidate for pneumonia. And we swallow liquid (saliva)
almost constantly.
.
I once challenged the class not to swallow for the entire
period; and after 15 minutes we all looked like a pack of rabid writhing
wretches. Because the class was mostly girls you could say that we were a
"room of rabid writhing retching wenches."
.
Sorry about that, I just like tongue twisters.
.
Obviously most of us have not choked on our food nor
gotten pneumonia. That is because nature has built in some safeguards.
.
At the top of the trachea, which is a cartilaginous
ringed tube, is a valve "box" which can close the entrance to the
tube. This is made up of two cartilaginous sections: the cricoid and the
thyroid cartilage.
The Larynx (not to be pronounced "Larnyx") is a valve system
at the top of the Trachea to keep food out.
.
The cricoid cartilage is like the final ring of the
Trachea, only somewhat more complex. The Thyroid cartilage is shaped like a
shield attached to but placed in front of the cricoid cartilage. This is what
people are seeing when they observe the "Adam's Apple."
.
This structure is commonly called the voice box, but
more correctly it should be labeled the "Larynx." Caution, do not
call it the "larnyx!" This can cause a major stroke in some speech
professors.
In the Larynx, the vocal folds open and close to let air pass and to
keep food from falling down the Trachea.
.
Stretched across the opening of the cricoid cartilage
are the two vocal folds made mostly of connective tissue. They are always
closed in front at the point where they meet, but swing open and shut from the
other end.
.
The rapidity with which these folds can open and close
(an alternating movement called diodochokenesis) is unparalleled in the body.
When we swallow, the vocal folds close snuggly. There is actually another point
of closure just above the folds called the False Vocal Folds.
When the vocal folds are shut and air if forced through, they will
vibrate and produce a sound.
.
The false vocal folds are not as well controlled as the
real ones. But I have had at least one student who used them to vocalize. It
was a real harsh sound and a problem for him because he couldn(tm)t use his
regular folds.
.
Other mechanisms to keep food from being swallowed
include the raising of the larynx during swallowing. You can actually see this
on someone else as the "Adams Apple" goes up an down.
.
There is a cartilaginous slide over the entrance called
the epiglottis, and folds along the side of the entrance to the larynx to catch
particles of food. There is also a liberal system of cough reflexes to expel
particles of food. Together, these safeguards work pretty well most of the time.
.
The serendipitous part for speech is that when the
folds are shut and air is forced through, sound vibrations are produced.
The only changes in sound we can make at the level of the larynx is to
raise and lower the pitch and loudness.
.
The action of the vocal folds is much like that of the
lips when we make the "Bronks Cheer." We hold our lips together
firmly and force the air though to make them vibrate, albeit with a sputtering
sound.
.
The vocal folds are much smaller, of course, and capable
of faster and finer vibrations. The result is the beginnings of voice. Not that
it sounds all that great, at that point. Originally, it is really a rather
pitiful squeak.
.
It is left to the resonators to shape the vocalization
into something we would recognize as a human voice.
.
The only changes we can impose upon sound at the level
of the larynx are to raise and lower the volume (which is really a matter of
breath control) and to raise or lower the the pitch. The latter we do by
changing the tension of the vocal folds.
.
Typically, the mass of the vocal folds remain constant.
However, there is a rapid increase in mass for boys particularly, during
puberty.
When the vocal folds are abused they may swell, which causes a drop in
the pitch of the voice.
.
Also, when we get a cold, the irritating secretions
generated by the sickness, or the wear and tear on the vocal folds created by
the frequent coughing spasms may cause them to become swollen.
.
The increased mass gives rise to a deeper fundamental
tone and hence, a deeper voice. We then say that we sound like we have a
"frog in our throat."
.
Yelling a lot can cause the same problem.
.
If yelling persists it can cause calluses to grow on
the folds. These are called vocal nodules. Vocal Nodules diminish the naturally
smooth seal between the folds. This requires more energy to produce a tone and
causes even more damage to the folds.
.
Eventually the calluses become as hard as fingernails
and are difficult to get rid of. The voice quality is typically
unpleasant--low, harsh and breathy.
The greatest threat to the health of the vocal folds is smoking.
.
Vocal abuse and its consequence of vocal nodules can be
a major problem for young singers. If they have not learned proper techniques,
they will often require more intensity to sing than is typically necessary and
healthy for the folds. Tragically the drive to keep performing eventually ends
in the inability to keep singing at all.
.
The greatest single threat to the vocal folds, however,
is smoking! The caustic nature of cigarette smoke with it cyanide, and many
other poisonous gases acts to suppress the immune system.
.
This in general creates more frequent sicknesses and
slower healing processes, and eventually a very high risk for cancer of the
larynx. What may be worse to some people, of course, is that smoking causes
deep creases in our favorite passport--the face.
.
The good news about laryngeal cancer is that it is
easily detected. The pitch of the voice typically drops noticeably which
eventually catches the patient(tm)s and the doctor(tm)s attention.
A person who has his/her larynx removed is called a laryngectomee.
.
The bad news is the threat to life that laryngeal
cancer poses because of its proximity to many lymph nodes in the neck. Should
the cancer break through to these nodes it could be spread throughout the body.
.
The good news is that this can be totally prevented in
many cases by totally removing the larynx (laryngectome).
.
The bad news is that once this is done, there is no
valve at the top of the trachea to prevent food and liquid from spilling into
the Trachea.
.
The good news is that this can be remedied by attaching
the upper end of the trachea to a hole (stoma) in the neck. The patient then
breathes though this hole in his/her neck. Now, there is no connection from the
lungs to the mouth.
.
The bad news, of course, is that there is now no vocal
folds nor air flow to produce sound for speech. Its hard for any one to imagine
the isolation that people experience when they can't speak.
A laryngectomee has no voice, and must use an artificial larynx or
esophageal speech to communicate.
.
Writing is not a good substitute for conversational
speech. Sign Language is, but more often than not, the community of the patient
does not know Sign Language and is reluctant to learn.
.
The good news is that there are alternatives. Since it
is the generator that has been lost, if we can find another, we are back in
business.
.
We have already mentioned "Donald Duck" talk
with the back of the oral cavity.
.
A more viable source of vibration is the esophagus.
Everyone has "burped" sometime in their life. If they
"mouthed" a word as they did so, they could produce an audible word
or two.
.
Esophageal speech is based on the same principle. Only
small amounts of air are injected by the tongue into the top entrance of the
esophagus where it is forced out again with a vibration.
Esophageal speech takes time and effort to learn, and the artificial
larynx sounds mechanical.
.
The bad news is that, as a passport to society, there
is much to be desired. In the notes below I give an example of esophageal
speech. When I do this in class, many students report they feel ill.
.
The good news is that with practice you can improve. In
the Movie, Jack Hawkins, the actor who played the Judge was a laryngectomee and
was using esophageal speech. I highly recommend renting the video to observe
this actor. Its an excellent movie, too.
.
The alternative to esophageal speech is to obtain an
artificial source of vibration. Battery operated oscillators can be placed on
the throat or cheek to cause the oral cavity to resonate.
.
If the words are then "mouthed," audible
speech is produced. An advantage of this over esophageal speech is that longer
sentences can be produced, and little practice is needed. The disadvantage is
that it sounds very mechanical.
Juvenile Pappiloma is an aggressive growth on the larynx of some young
children that requires medical attention.
.
Actually, the best advise is to not smoke. The human
voice without question the best of all passports. Not that people don't get
laryngeal cancer form other causes. Sometimes it is unavoidable.
.
But every time I see a teenager "light up," I
feel sad because somehow I feel that that should have been avoidable. The
message should, but is not getting through.
.
Juvenile Pappiloma is another type of growth on the
vocal folds that afflicts some young children. Its like having warts that grow
very fast. Although it effects the voice, the major concern is breathing.
.
The growths must be surgically removed many times.
Fortunately, they frequently cease to be a problem after puberty.
A series of resonating air chambers above the larynx alter the overtones
to create the human voice.
.
There are three major resonating cavities above the
larynx: The Pharynx, the Nasal Cavity and the Oral Cavity.
.
The pharynx (not the be pronounced -pharnyx...) is the area
directly above the the larynx, in the back of the throat up to the oral cavity.
.
It is not typically changed during speech, although
under conditions of overall body tension, it can be constricted.
.
Modulator: The complex tone produced by the
larynx alone does not particularly sound human. It is the action of the
resonating air chambers above the larynx that shape the sound into its human
form by screening, and hence modifying, the pattern of overtones.
.
Air in an open area does not typically resonate, but in
an enclosed areas, such as a bottle it will. Hence, the cavities in the air
channels leading to the larynx can serve as resonators.
The Pharynx and the Nasal Cavity are two resonating cavities that shape
the sound produced by the Larynx.
.
Constricting the pharynx typically degrades the quality
of the resonation. However, voice impersonators, like Rich Little, do amazing
things by bring this resonator under voluntary control.
.
Others of us find an improved quality of voice when we
learn to relax the muscles around the pharynx. Bing Crosby was probably the
most relaxed man on earth when he sang.
.
The Nasal cavity is well known to anybody (everybody)
who has had a head cold and has experienced the discomfort of having a stuffy
nose. Try to say under those conditions the phrase ("Eminent Women.")
It comes out ("Ebidedt Wobed").
.
Ironically, in English, there are only three sounds
that use nasal resonance (i.e., are produced with the soft palate {velum}
open.)
Only three sounds in English use Nasal Resonance.: "m,"
"n," and "ng."
.
The only three nasal phonemes in English are:
"m" as in "mam," "n" as in "non," and
"ng" as in "-bong."
.
If you prolong those three sounds while placing your
fingers on the side of your nose, you can feel the resonance. Try it and then
alternate making a non nasal sounds (i.e., any vowel or other consonant).
.
Although there are only three nasal phonemes, they
occur in speech with an especially high frequency.
.
Sometimes if a child(tm)s movement of the velum is
sluggish, the sounds on either side of a nasal phoneme may also acquire a nasal
resonance. This is called assimilation, and would occur in a word like,
"man;" but not in "pat."
.
When vowels are nasalized, they are still recognizable,
although the resonance may sound a little whiney.
The Oral Cavity is the major Modulator of the three resonating cavities.
.
When consonants other than -m, n and ng... are
nasalized, they become unintelligible. This is because the air pressure needed
to make a consonant escapes through the nose.
.
The Oral Cavity is the most amazing of all resonators.
It is a modulator in that it can easily change in many ways the nature of the
overtones generated by the larynx.
.
Using the articulators (particularly the jaw and the
tongue) the size of the air masses in the oral cavity can be easily and quickly
modified.
.
This is one major advantage of oral speech over Sign
Language. The latter requires considerable effort (relatively speaking). My
class on campus, which is three hours long, requires at least two Sign Language
Interpreters. One only for the whole three hours would be a good candidate for
Carpal Tunnel Syndrome.
The Oral Cavity can produce phonemes with a minimal expenditure of
movement and energy.
.
So relatively minimal is the movements for speech, that
I have never heard of a single professor coming down with Carpal Tunnel Syndrome
of the Tongue.
.
To the contrary, the tongue is the strongest muscle in
the body (inch for inch), and has a large quantity of neural tissue in the
brain devoted to it's control.
.
It can assume a number of different shapes in the oral
cavity with a minimum expenditure of energy.
.
For example it can arch in the front, middle or back;
and can at the same time be raised or lowered.
.
As the air masses around the tongue in the oral cavity are
changed (thus changing the natural frequencies) their screening potential for
overtones changes. Each change in the pattern of overtones creates a new vowel
sound.
.
Actually, that is only partly true, because we do not
really produce discrete phonemes. What do we do?
Actually, speech is not a series of discrete phonemes, but a continuous
modulated flow of vocalized sound.
.
What we produce in speech is a continuous flow of
modulated frequencies. You get a notion of how this sounds when you play speech
backwards.
.
It is in truth, the listener, who superimposes his/her
own template (expectancies) of phonemes on perceived running speech, that turns
the continuous flow into apparent sequences of discrete phonemes.
.
That's one of the factors that makes foreign languages
so difficult to learn for adults.
.
As an English speaker, when I hear Japanese, I
automatically try to fit the stream of sounds into English phonemes. As a
result I will fail to hear many important phonemes that are not in the English
Language.
.
But what do babies, who have not had time to develop a
template of phonemes, hear? They simply hear the continuous modulated flow of
speech. How, then, do they develop the template?
Babies do not perceive phonemes, but instead can hear all of the
distinctive features that build the phonemes of every language.
.
Babies hear no phonemes in those first few months of
life.
.
Ironically, however, their hearing is fully functioning
by the time of birth. In addition, they possess some rather amazing auditory
perceptual skills, apparently wired in before birth, which make them in some
ways superior listeners to adults.
.
Whereas they don't hear the phonemes of a language,
they can perceive the building blocks (the distinctive features) of all
languages!
.
It is believed that the neural connections for
distinctive features that are reinforced by the environment are strengthened,
while those that are not stimulated are lost.
.
Hence in adulthood, my ability to hear the distinctive
features that contribute to phonemes of languages not spoken in the home when I
was a child, is lost.
.
A good example is Voice Onset Time.
Voice Onset Time is a good example of a distinctive feature that babies
perceive, but we as adults may not.
.
In English, if we start the laryngeal tone exactly at
the beginning of the "P" sound, it becomes (is perceived as) the
"B" sound. If we delay progressively longer in small increments the
beginning of the voice (voice onset time), there is a point in time that it
would become the "P" sound. If a line under the wordd represents the
beginning of the voice, it would look like this:
.
B I T
.
P I T
.
Because as babies, we were exposed to verbal experiences
in which those phonemic boundaries were used, we can discriminate these sound
differences today.
.
But there are some languages that include a Voice Onset
time before the beginning of the consonant:
.
B I T
.
_ B I T
.
If the two words above were spoken and heard by a
speaker of such a language, the two would be heard as different words--although
to us they would sound and be the same.
It is advantageous to have speakers of other languages talk to babies
who are not high risks for language delay.
.
This is certainly one good argument for having family
members who speak other languages talk to babies while they are young, to
reinforce those neural tracks. This of course applies to babies who are not
high risk for language delay.
.
I was asked in class if it would be beneficial to play
language records in the presence of the child when they are babies. This would
be an interesting topic for a doctoral dissertation for someone who has a baby
and doesn(tm)t mind the background clamor.
.
Please let me know the results of your findings!
.
So what are those distinctive features that babies
hear. There are books written on them. If you want to punish yourself severely
for some indulgence, check one out on a Saturday evening and try to read it. In
comparison, it makes a plumbing catalog seem like a romantic novel.
.
To give you a small flavor of what it is all about, we
will limit ourselves to a discussion of just four each for vowels and
consonants.
The Place of Constriction of the air flow through the vocal tract is one
distinctive feature for consonants.
.
The four Distinctive Features for Consonants, that I
have selected to discuss, include the Place of Articulation, the Manner, the
inclusion of larynx (plus or minus voicing) and the inclusion of nasal
resonance (plus or minus nasality resonance).
o There
are certain locations along the oral tract (phonemic boundaries) where
constriction has the potential to create a different phoneme. These locations
can be described from front to back. Different languages select some boundaries
that are the same and others that are different.
o
In English the most forward constriction boundary is
the two lips (e.g., the bilabial "B").
The place of constriction can be described in terms of locations
proceeding from front to back in the vocal tract.
o
There is, of course, the potential for a labio-nasal
sound which no one has mastered yet. If you can master it you are eligible to
receive the Grand Prize offered as an
incentive in this course.* The sound is made by flinging the lower lip over the
tip of the nose while expelling air through the mouth. Do not try this at home,
however, but only near a medical setting.
o
*(The Grand Prize is: A full body size autographed
photo of your instructor which can be placed in the living room.)
o
Getting back to English, and reality, the next place of
constriction would be the lower lip on the upper teeth (e.g., the labio-dental
"F"). This would be followed by the tongue between the teeth (e.g.,
the inter-dental "TH"); the tongue on the gum ridge (alveolar ridge
for "T" and "S"); the tongue a little farther back on the
palate (for "SH"); and the back of the tongue on the soft palate
(velum for "K").
The baby is capable of perceiving the constriction boundaries of English
and all other languages.
o The
farthest back you can go in English (and in any language as far as I know) is
the glottis (the space between the vocal folds) to produce the "H"
sound. Here we create air friction through the partially open folds, much as we
do when we whisper.
o
In other languages, there are many intermediate
locations for constriction that we don(tm)t have in English. An interesting one
to me is the "X" sound in Russian, which to me sounds like
"H" but is made farther forward.
In vocalizations, back consonants appear first during the reflexive
stages, but front consonants appear first in the voluntary stages.
The Manner of Articulation is a second Distinctive Feature for
Consonants.
. The
Manner of Articulation: Sometimes the point of constriction for two or more
phonemes is the same. What differs is the manner in which they are made. Let me
give three examples: Plosives, Fricatives and Affricates.
o
For Plosives, the air flow is completely
blocked, thus creating a build-up of pressure. When the constriction is
abruptly removed, the air escapes in with mini explosion (e.g., "P,"
"T" and "K").
The addition of a tone from the Larynx (+Voicing) to the noise of a
consonant provides a third distinctive feature.
o The
"CH" sound starts out as the plosive "T" and ends up as the
fricative "SH."
o Sometimes
when a child has a lateral lisp for the "SH" sound (i.e., it sounds
more like "SHL"), he/she will nevertheless make the "CH"
sound correctly. When this happens, the "SH" part of this affricate
can be use to teach the child to make the "SH" sound correctly.
o
The other example of an affricate is the first (and
last) sound in the word "judge."
Nasality, a fourth distinctive feature of consonants, is used in only 3
phonemes in English: "M," "N," and "Ng."
o
The answers are "B," "D,"
"V," "Z," and "G." The affricate in
"judge" is also voiced.
The place of articulation for vowels refers to the arching action of the tongue
to produce front, mid or back vowels. .
We will switch now to some (four) of the more
interesting distinctive features of vowels. The four I have chosen to discuss
are: The place of articulation; the height of articulation; tense versus lax
vowels; and lip rounding.
In vocalizations, front vowels appear first during the reflexive stages,
but back vowels appear first in the voluntary stages.
o
When the tongue arches in the back we have back vowels.
An example would be the vowel in the word:
.
"soon"
o
During the period of reflexive vocalizations for the
baby, the vowels that will be heard most frequently are the front vowels.
The tongue raises and lowers to produce an array of front and back
vowels.
The position of the jaw will drop for low vowels to facilitate the
movement of the tongue.
For some vowels, the tongue is more relaxed than for others.
Lip rounding is more essential for lip reading than for sound
production.
Lip rounding is an important visual component in the perception of
speech.
The key to good phonemic development is for the parents to spend much
time talking to and around their baby.
It remains for the parents to
provide the materials (speech sounds) for the child to maintain and strengthen
these listening skills. The child who sits alone for long hours in a crib will
be at a disadvantage relative to the child who has doting parents hovering
about and talking to and chatting about their child.
And if one of the parents is
speaking another language, better yet for the baby's developing phonemic
structure.