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I am a researcher in
generative (or theoretical) linguistics. Linguistics is roughly the study of
the structure of human language.
Broadly, I concentrate on phonology, the phonetics-phonology interface
and the phonology-morphology interface. Basic definitions and examples of phonetics, phonology and morphology
are given below. 1.
Phonetics: the study of the physical attributes of speech
sounds - articulation (vocal organs), perception (auditory organs), and
acoustics (sound waves) Examples
of the major articulators and the auditory system are shown below, as is a
graphic representation of the sounds used in the word “spectrogram”. The major vocal and auditory organs On
the articulator side of things, our brain sends signals to the mobile articulators
on the lower side of the vocal tract (e.g. lower lip, tongue, etc.) to move
closer to or farther away from the immobile articulators on the upper side of
the vocal tract (e.g. upper lip, tooth-ridge, hard palate, etc.). This results in various speech
sounds. On
the auditory side of things, our outer ear (e.g. pinna, ear canal, etc.),
middle ear (e.g. malleus, incus, stapes, etc.) and inner ear (e.g. vestibule,
cochlea, etc.) detect speech sounds and then send signals along the auditory
nerve. The brain then interprets
the signals it receives from the auditory nerve.
On
the way from the vocal tract to the auditory system, speech involves sound
waves. These sound waves can be
graphically presented in several ways that help us to “see” certain
characteristics of those sounds. A
waveform is a two-dimensional depiction of speech sounds. The x-axis is time, while the y-axis
is amplitude. This means that it
shows the loudness of the voice over time. A
spectrogram is a three-dimensional depiction of speech sounds. The x-axis is time, the y-axis is
frequency and the z-axis (the darkness of the display) is amplitude. This means that it shows the loudness
of certain frequencies over time. There
are several interesting things that one might notice about the waveform and
spectrogram showing my pronunciation of the word “spectrogram”: ·
The “s” sound has
fairly loud high-frequency noise.
Note that the signal is dark and kind of spread out at the high end of
the visible frequency range on the spectrogram. ·
The “p”, “c” and “t”
sounds are relatively silent.
That is, the signal is very light. ·
There are actually two
kinds of “r” in this word. The
first has fairly soft mid-frequency noise. The second is rather loud at three distinct low
frequencies. This is indicated
by three rather dark bands. ·
The “a”, “e” and “o”
vowels differ from one another in relative duration. The “a” is very long,
the “e” is shorter and the “o” is very short. ·
The “a”, “e” and “o”
vowels also differ from one another in their loudest three frequencies. The
frequencies of the “a” and the “e” are very similar in this dialect. However, the three loudest
frequencies of the “o” are much lower.
2.
Phonology: the study of the patterns of human speech sounds and
the nature of the mental representation of those speech sounds An
example of the mental representation of the French sound “b” is shown in the
following figure (using the Parallel Structures Model of feature geometry
that I have been developing over the past several years). This sound is composed of several
components (i.e. features) based on the articulatory system. ·
It is made by
completely closing the vocal tract. This is represented by C-manner[closed]. We call the amount of constriction or
expansion of the vocal tract “manner of articulation”. ·
It is made with both
lips. This is represented by
C-place[labial]. We call
the place where the vocal tract is constricted or expanded “place of
articulation”. ·
It is made with vocal fold
(i.e. cord) vibration, which results from holding the vocal folds loosely
together and blowing enough air through to cause vibration via the Bernoulli
Effect. This is represented by C-laryngeal[lax]. We call the adjustments
of the vocal folds “state of the glottis”. Combining
all three characteristics (manner of articulation, place of articulation,
state of the glottis) into a single unit, we get a French “b” sound. 3.
Morphology: the study of the structure of words An
example of word structure is shown below using “denationalize”. This word can be broken down into
several components that contribute to the overall meaning and combine in a
particular order. ·
The noun “nation”
combines with the suffix “-al” to form an adjective. ·
The adjective
“national” combines with the suffix “-ize” to form a verb. ·
The verb “nationalize”
combines with the prefix “de-” to form a verb with a different meaning.
4.
Example of
phonetics, phonology and morphology combined: the behavior of the English plural “s” (simplified) ·
Some English
consonants are made with vibrating vocal folds (e.g. “v” and “z”). Other
English consonants are made without vibrating vocal folds (e.g. “f” and “s”).
To feel the difference, put your hand on your Adam’s apple and say,
“zzzssszzzsss.” ·
English (like many
languages) insists that certain combinations of consonants within words
either all have vibration or none have vibration. ·
This requirement can
cause sounds to change from one instance to the next depending on the
context. This is what we call a
sound alternation. ·
So, if we take the
English plural “s” and add it to words either ending in vibrating or
non-vibrating sounds, the “s” will surface as vibrating or non-vibrating
depending on what it is next to. “wave” + “s” versus “waif” + “s” The
following diagrams show the morphological structure of the plural form of
“wave” and “waif”.
The
following diagram shows the phonological relationship between the “v” and “s”
in “waves”. ·
The C-manner[open]
feature indicates that the vocal tract is open enough to cause a hiss-like sound
- what we call a fricative. ·
The C-place[coronal]
feature indicates that the front of the tongue is raised toward the roof of
the mouth just behind the teeth. ·
The dashed line
indicates that the plural “s” is pronounced as a “z” in this context because
it shares the C-laryngeal[lax] with the preceding “v” sound.
The
following diagrams show the vibration shared by the “v” and beginning of the
plural in “waves”, and the lack of vibration during the “f” and beginning of
the plural in “waifs”. I have
indicated the vibration with labeled brackets. One can see the vibration as a sequence of short dark
lines at low frequencies in the spectrogram. Waveforms and spectrograms of the words “waves”
and “waifs”
5.
Phonetics-phonology
interface: the relationship between
the mental representation of speech sounds and their
articulatory/perceptual/acoustic correlates. 6.
Phonology-morphology
interface: the relationship between
the mental representation of speech sounds and their combinations within words
and/or meaningful subparts of words. Sign
language phonetics and
phonology Part of my research
includes comparing the phonetics and phonology of signed and spoken
languages, looking for similarities and differences, and developing a theory
to explain the facts. Below is
just a sample of this. Recall that phonetics is
the study of the physical attributes of “speech sounds” and that phonology is
the study of the mental representations of “speech sounds.” These definitions are slightly
misleading because signed languages also have a “phonetics” and a “phonology”
that works just like spoken languages, despite the fact that they do not
(usually) use sounds. Therefore,
we should really use the more neutral term “segment” to refer to both spoken
and signed language “speech sounds.” 1.
Phonetics Just
like spoken languages use a set of active articulators (e.g. movable - lower
lip, tongue tip, tongue blade) and passive articulators (e.g. stationary -
upper lip, upper teeth, roof of mouth), sign language also uses a set of
active and passive articulators.
The difference is in the parts of the body used as articulators. Rather than relying on the vocal
tract anatomy, which is good at making distinct sounds but is not easy to
see, sign languages use the hands and other parts of the body, which are easy
to see. Further, the combination
of active and passive articulator for both spoken and signed languages is
subject only to physical limitations, and sign language seems to have fewer of
these limitations. For example:
Spoken
and signed languages also use degrees of constriction to distinguish among
segments. For spoken language,
this constriction shapes the vocal tract to create different types of sounds
(i.e. manner of articulation).
For sign language, this constriction creates different handshapes.
2.
Phonology If
we assume that the mental representation of all languages (including the
segments of spoken and signed languages) is the same, but that articulation
can differ from language to language, then we find that spoken and signed
languages are actually much more similar than is usually assumed. This can be seen if we compare the
representations for English “f” and the American Sign Language “i”. Here we see that each segment has
C-manner[open] corresponding to the degree of constriction. For spoken languages, this entails a
fricative (i.e. “hissing” sound) and for signed languages, this entails a
mostly closed handshape (i.e. a fist) but with at least one finger extended. We also see that each segment has a
C-place feature corresponding to an active articulator.
In
fact, the following diagrams illustrate phonological similarities between
spoken and signed segments using my Parallel Structures Model. Spoken
Segment Geometry versus Signed Segment Geometry
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Last updated May 2010 -- By the way, my name is pronounced approximately like [mɔˈɹejn ˈtʷollʲɑː]. |
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