VOWEL SOUNDS

INTRODUCTION

In English, five or six letters are used to represent vowels in writing: a, e, i,

o ,u and sometimes y. Unfortunately, there are many more vowel sounds than five
or six in English. There are not enough letters in the alphabet to represent all the
English vowels.

To represent the pronunciation of all vowels (and consonants), we will use a

different kind of alphabet called the International Phonetic Alphabet or the IPA.
You will not need to learn the symbols in the IPA, but we will use them from time
to time to help distinguish the sounds.

By the end of the chapter, readers will be able to…

 recognize some symbols in the IPA

 describe how individual vowels are produced
 describe how vowel diphthongs are produced
 produce vowel sounds and diphthongs in different words and phrases

HIGH-LOW, FRONT-BACK, AND (UN)ROUNDED VOWELS

An introduction to the pronunciation of vowels requires a little understanding of

how the sounds are made in the mouth. It’s also important to hear the sounds
individually and in words.

This video from Ubc Visible Speech provides an overview of the pronunciation of
vowels. There are two kinds of vowel
sounds monophthongs and diphthongs. Monophthongs have one vowel sound such
as in the words “cat” and “sit.” Diphthongs have two vowel qualities. More
information about diphthongs is given below.

Three criteria are used to describe the pronunciation of vowels: height, backness,
and roundedness. These criteria refer to the position of the tongue and the lips.

 Three tongue positions refer to height: high, mid, low.

 Three tongue positions refer to backness: front, central, back
 Roundness refers to whether the lips are rounded or unrounded.

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You can see the positions in this illustration of the vocal tract. The high vowels are
represented by the IPA symbols [i], [ι], [ʊ], and [u].

The low vowels are represented by the symbols [æ] and [a]. The front vowels are
[i], [ι], [e], [ɛ], and [æ] and the back vowels are [u], [ʊ], [o], [ɔ], and [a]. The mid
central vowel is the shwa represented by [ə].

The Vocal Tract

Words with High-Low, Front-Back, and (Un)Rounded Vowels

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 TENSE AND LAX VOWELS

Vowels can be tense or lax. Tense vowels are pronounced with more tension in the
vocal tract and lax vowels are pronounced with less tension. This video from Learn
English with TIE explains differences between tense vowels and lax vowels.
Sometimes these vowels are referred to as short and long but a more accurate way
to describe them for pronunciation is tense and lax.

Tense vowels are pronounced with more tightness in the tongue, lips, and mouth
more generally. Lax vowels are pronounced in a more relaxed way with less
tension. Practice the sounds and words with the speaker in the video to feel the
difference between tense vowels and lax vowels.

Now listen to the the audio file and look at the words below. Listen for the
difference between tense and lax vowels

Words with Tense and Lax Vowels

 beat (Tense) — bit (Lax)

 bait (Tense) — bet (Lax)
 boot (Tense) — book (Lax)
 boat (Tense) — bought (Lax)

The tense vowels, however, are not “pure” vowels. They are pronounced with a
slight offglide. The offglide adds a brief [y] or [w] sound to the vowel. The sounds
[i], [e], [u] and [o] are actually pronounced as: [iy], ey], uw], [ow].

DIPHTHONGS: [aι], [aʊ], and [ɔι]

Diphthongs are two vowel sounds pronounced together as in the words lie, cow,
and toy. The linguistic symbols that represent these words are: [laι] for lie, [kaʊ]
for cow, and [tɔι] for toy. Notice that two linguistic symbols are used to represent
the two vowel sounds, which are pronounced together.

The [aι] Diphthong

This video from Sounds American explains and gives examples of how the
diphthong [aι] is pronounced. To hear the sound and see a diagram, click on the
video. At the end of the video (minute 8:22), the speaker considers the sounds [eι]
as in face and [oʊ] as in no. Are these sounds diphthongs or monophthongs? One

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similarity with diphthongs is that both [eι] and [oʊ] are pronounced as moving or
“gliding sounds,” which makes them like diphthongs. When studied carefully,
however, there is not quite as much movement in the vocal tract when these two
sounds are pronounced when compared with [ɔι], [aʊ], and [aι]. The takeaway
point is that the tongue, jaw, and lips need to move a lot when pronouncing English
vowels, especially diphthongs.

The [aʊ] Diphthong

When pronouncing [aʊ] as in the word round, begin with a low vowel. This means
you will need to lower your jaw. Then, move your tongue to a high back position
and round your lips. When this diphthong is pronounced as a stressed sound as
in round, the jaw is lower and the sound is held longer. The diphthong can also be
unstressed and shorter. In this case, the jaw is not as low and the lips are not as
rounded. An example is the word shutdown as in the sentence, “the governmental
shutdown caused many problems.” This video from Rachel’s English provides a
good example of how this diphthong is pronounced.

The [ɔι] Diphthong

The next diphthong is [ɔι] as in the words joy, point, and soil. This sound begins
with a mid-back vowel and some lip rounding. Then, the tongue moves to the high,
front position and the lips are unrounded. This short video
from bbclearningenglish.com shows how this sound is made. It is important to see
how the jaw and lips move to pronounce this sound in words such as: choice,
noise, and boy. The speaker has a British accent, but the sound is quite similar to
the North American pronunciation.

THE NORTH AMERICAN R-SOUND AND SOME R-DIPHTHONGS

For some people, the r-sound can be difficult to pronounce. A reason for the
difficulty is that this sound is pronounced in different ways depending on the
country and the region of the country. To make it easier to pronounce, the
examples and illustrations used here are typical of the North American r-sound and
r-diphthongs.

Tense and Lax R-Sound

The r-sounds [ɝ] and [ɚ] are vowels and their pronunciation is similar. The [ɝ]
sound is tense and stressed as in the word first. The sound [ɚ] is not stressed, so it

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sounds “weaker” as in the word after. A description of this sound and some
example are in this video from Sounds American.

The R-Colored Vowel [ir]

The r-sound can also be a diphthong when it combines another vowel. The addition
of the r-sound slightly changes the vowel sound. This change can be described as
“adding some color” to the vowel sound, so this sound is sometimes called r-
colored vowels. An example is the vowel [ι] + [r] as in words like hero, here,
clear, deer, and zero. The North American and British pronunciations of this “r-
colored” sound are different. For instance, the word deer is pronounced as [dιr] in
many places in North America. In British English, however, the [r] sound is
reduced to [ə]. The word deer is pronounced as [dιə]. This video from Sounds
American has diagrams of how this sound is pronounced in North America and
offers examples from words such as appear, career, and cheer.

The R-Colored Vowel [ɔr]

Like all diphthongs, the key to pronouncing this sound is to make a smooth
connection between sounds, in this case between the [ɔ] and the [r]. This r-colored
vowel is in words such as sport, four, orange, and sword. Some speakers of North
American English pronounce this diphthong as [o] + [r] rather than [ɔ] + [r]. Either
way is fine! We can see an illustration of how this sound is pronounced in the
vocal tract and hear examples of the pronunciation in this video
from Sounds American.

The R-Colored Vowel [ar]

When pronouncing r-colored diphthongs, be sure not to reduce the [r] sound. To
pronounce this diphthong, start with the [a] sound. Lower your jaw to open your
mouth wide and place your tongue low and flat at the bottom of your mouth. Then,
transition to the [r] sound by rounding your lips, curling the tip of your tongue, and
“bunching” the back of the tongue as show in the diagram below.

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This video from Sounds American offers more explanation and examples of how to
produce this vowel.

The R-Colored Vowel [ɛr]

This diphthong appears in words such as air, care, fair, hair, share, and bear. The
first sound in this diphthong is the mid, front, lax vowel [ɛ] as in the word bet. To
pronounce the diphthong, start with [ɛ] and then move your tongue into the [r]
sound. This video from Speech Modification Accent Training models the
pronunciation of [ɛr] in three words: air, care, and airport. Notice that the [r]
sound at the end of a word can connect or blend with the beginning sound of the
next word as in care + about, which is pronounced as “care-rabout.” (The “e”
in care is not pronounced.)

Describing vowels
Vowel quality
Vowel phones can be categorized by the configuration of the tongue and lips
during their articulation, which determines the vowel’s overall vowel quality.
Vowel quality is often much more of a continuum than consonant categories
like place and manner. A slight change in articulation makes little difference in
what a vowel sounds like, but it can have a drastic effect on a consonant. For
example, moving an active articulator away from a passive articulator by just a
tiny bit, less than 1 mm, is enough to turn a stop into a fricative, but that same
distance for a vowel will have no noticeable effect. However, we can still
identify several broad categories of vowel qualities based on dividing up this
continuum into a few major regions.
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Height

Vowels are articulated with a larger opening in the oral cavity than consonants
are, requiring the tongue to move farther down than for approximants. This is
typically facilitated by also moving the jaw down to allow the tongue to move
even lower. The height of the tongue during the articulation of a vowel is
called vowel height, or simply height for short.

A vowel with a very high tongue position, as in the English word beat, is called
a high vowel. Some linguists instead call this a close vowel, but we will not
use that terminology here. High vowels have an opening just slightly larger
than for approximants. Indeed, high vowels and approximants are often
related in many languages, with one turning into the other in certain positions.
Compare the different pronunciations of the phone represented by the
letter i in the middle of the English words unique (with a high vowel)
and union (with an approximant).

A vowel with a very low tongue position, as in the English word bat, is called
a low vowel. Again, some linguists have a different term that we will not use,
calling these vowels open instead. Low vowels have the largest opening of
any phone, whether vowel or consonant.

A vowel with an intermediate tongue position between high and low, as in the
English word bet, is called a mid-vowel. The differences in vertical tongue
position for these three categories of vowel height are shown in Figure 3.13,
from highest on the left (as in beat) to lowest on the right (as in bat). Note how
the jaw also lowers along with the tongue in these diagrams.

Figure 3.13. Three categories of vowel height: high as in beat (left), mid as in bet (centre), and
low as in bat (right). Each height is also represented with a line across all three diagrams for ease
of comparison: high (magenta), mid (cyan), and low (orange).

Backness

The horizontal position of the tongue, known as its backness, also affects
vowel quality. Backness could equally be called frontness, and sometimes this
term is used, but backness is more standard and preferred. If the tongue is
positioned in the front of the oral cavity, so that the highest point of the tongue
is under the front of the hard palate, as for the vowel in the English word beat,
the vowel is called a front vowel.

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If the tongue is positioned farther back in the oral cavity, so that the highest
point of the tongue is under the back part of the hard palate or under the
velum, as in the English word boot, the vowel is called a back vowel.

If the tongue is positioned in the centre of the oral cavity, so that the highest
point of the tongue is roughly under the centre of the hard palate, in between
the positions for front and back vowels, as for the English word but, the vowel
is called a central vowel. Be careful not to confuse the technical
terms central and mid. Central refers to an intermediate position in backness,
while mid refers to an intermediate position in height. These two terms are not
interchangeable! The differences in horizontal tongue position for these three
categories of vowel backness are shown in Figure 3.14. from frontest on the
left (as in beat) to backest on the right (as in boot).
Figure 3.14. Three categories of vowel backness: front as in beat (left), central as in but (centre),
and back as in boot (right). Each backness is also represented with a line in the same position in
all three diagrams for ease of comparison: front (magenta), central (cyan), and back (orange).

Note that what counts as front for a vowel depends on its vowel height,
because of how the jaw moves. Humans have a hinged jaw, which means that
as the jaw moves down to allow for a lower tongue position, the jaw also
swings backward, carrying the tongue along with it. As the tongue moves
backward due to this hinged movement, its centre position also moves
backward, and it becomes more difficult for this lowered tongue to move as far
forward as for a higher vowel.

In fact, the frontest position for a low vowel (as in the English word bat)
typically has an actual overall backness a bit farther back than for a front high
vowel (as in the English word beat). Thus, backness must be defined relative
to the possible range of horizontal positions at a given height, rather than
being defined in absolute terms with respect to the roof of the mouth. This
results in a skewed shape of the possible combinations of vowel height and
backness, with more distance between front and back positions for high
vowels than for low vowels.

This is often graphically represented as in Figure 3.15, with the total vowel
space drawn as an asymmetric quadrangle, like a rectangle with the bottom
left corner cut off. This missing corner represents the space where humans
cannot produce a vowel because of the how the tongue moves backward as
the jaw lowers. A few example words of English are listed in Figure 3.15 as
rough indications for what tongue position many speakers use for the vowels
in these words.

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 Figure 3.15. Standard vowel quadrangle
with example English words.

The cells in this quadrangle represent possible positions of the tongue within
the oral cavity. For example, beat is shown in the high front cell, which
indicates that it is pronounced with a high front tongue position. Note that
there is much variation in English vowels across speakers, so the positions in
Figure 3.15 are only meant to be suggestive of broad patterns across a range
of dialects. The positions of the tongue for the vowels in these words may be
somewhat different for you or for other speakers. For example, some
speakers may have a low or back vowel for but, and some may have a more
central vowel for bot or boat.

Rounding

Vowel quality also depends on the shape of the lips, generally referred to as
the vowel’s rounding. If the corners of the mouth are pulled together so that
the lips are compressed and protruded to form a circular shape, as for the
vowel in the English word boot in many dialects, the lips are said to
be rounded and the corresponding vowel is called
a round or rounded vowel.

If the corners of the mouth are pulled apart and upward so that the lips are
thinly stretched into a shape like a smile, as for the vowel in the English
word beat, the lips are said to be spread.

The lips may also be in an intermediate configuration, neither rounded nor

spread, as for the vowel in the English word but, in which case, the lips are
said to be neutral. Spread and neutral vowels are collectively referred to
as unrounded or non-rounded vowels, because the distinction between

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spread and neutral lips seems almost never to be needed in any spoken
language, whereas the distinction between rounded and unrounded frequently
is needed. The differences in lip shape for these three categories of vowel
rounding are shown in Figure 3.16.

Figure 3.16. Three

categories of rounding: round as in boot (left), neutral as in but (centre), and spread
as beat (right), where neutral and spread are also classified together as unrounded.

Tenseness

The position of the tongue root may also play a role in vowel quality. If the
tongue root is advanced forward away from the pharyngeal wall, as for the
vowel in the English word beat, the tongue root pushes into the rest of the
tongue. This causes the tongue to be somewhat denser and firmer overall, so
a vowel with an advanced tongue root is sometimes called a tense vowel. If
the tongue root is instead in a more retracted position closer to the pharyngeal
wall, as for the vowel in the English word bit, it keeps the tongue somewhat
more relaxed, so a vowel with a retracted tongue root is sometimes called
a lax vowel. The property of whether a vowel is tense or lax is
called tenseness. The different positions of the tongue root for tense and lax
vowels are shown in Figure 3.17.
Figure 3.17. Two categories of tenseness: tense with an advanced tongue root as in beat (left)
and lax with a retracted tongue root as in bit (right). Each tenseness is also represented with a
line in the same position in both diagrams for ease of comparison: tense (magenta) and lax
(cyan).

For many spoken languages, vowel tenseness is not a relevant property.

Languages like Taba (a.k.a. East Makian, a Central-Eastern Malayo-
Polynesian language of the Austronesian family, spoken in Indonesia;
Bowden 2001) have only five vowels that are spread quite far apart. There is
only one high front vowel, one mid front vowel, etc. These vowels can vary in
how tense or lax they might be from one pronunciation to the next, so there is
no need to use the terminology tense and lax to describe them.

However, other spoken languages have more complex vowel systems, with
vowel pairs articulated in roughly the same way, except for tenseness. For
example, most dialects of English have multiple pairs of vowels that are

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distinguished primarily by tenseness, such as the vowels in beat and bit. Both
of them have a high front tongue position and are unrounded, but
the beat vowel is tense, while the bit vowel is lax. Similarly, the vowels of the
English words bait and bet are both front, mid, and unrounded, but
the bait vowel is tense, while the bet vowel is lax. Thus, for languages like
English, the tense/lax terminology is often necessary to fully describe the
vowel system.

That said, low vowels are very rarely tense in any language, because lowering
the tongue and advancing the tongue root are making almost contradictory
demands on the tongue, pushing the bulk of tongue in two different directions.
However, the tongue is quite flexible and can physically be both lowered and
tensed, so tense low vowels are not impossible, and there are some
languages that have them, such as Akan (a Kwa language of the Niger-Congo
family, spoken in Ghana; Stewart 1967), which has both a tense and a lax low
vowel.

Nasality
In Section 3.4, we talked about how the velum can move to make a distinction
between oral and nasal stops based on whether or not air can flow into the
nasal cavity. The same distinction can be found for vowels. If a vowel is
articulated with a raised velum to block airflow into the nasal cavity, the vowel
is called oral. If instead the velum is lowered, allowing airflow into the nasal
cavity, the vowel is called nasal or nasalized. The property of whether a
vowel is oral or nasal is called its nasality. Vowels in most dialects of English
are often nasal when they are immediately before a nasal stop, as in the
English word bent. The different positions of the velum for oral and nasal
vowels are shown in Figure 3.18, with arrows indicating direction of airflow.
Figure 3.18. Two categories of nasality: oral with a raised velum as in bet (left) and nasal with a
lowered velum as in bent (right). Airflow is shown as blue arrows.

Length
In addition to differences in vowel quality and nasality, vowels may also differ
from each other in length, which is a way of categorizing them based on their
duration. In most spoken languages where vowel length matters, there is just
a two-way distinction between long vowels and short vowels, with long
vowels having a longer duration than their short counterparts. For example, in
Japanese (a Japonic language spoken in Japan), the word いい (ii) ‘good’ has a
long vowel, while the word 胃 (i) ‘stomach’ has a short vowel, although they
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both have the same vowel quality: they are both high front unrounded vowels.
The pronunciation of these two Japanese words can be heard in the following
sound file, first いい (ii) with a long vowel, then 胃 (i) with a short vowel.

In most dialects of English, vowel length is not used to distinguish words with
completely different meanings like it is in Japanese. However, English vowels
can still differ in vowel length in some circumstances. For example, English
vowels are often pronounced a bit longer before voiced consonants than
before voiceless consonants. Thus, the vowel in the English word bead is
usually pronounced longer than the vowel in the word beat, even they both
have the same vowel quality: high front unrounded. The tense vowels of
English also tend to inherently be a bit longer than their lax counterparts. For
example, the tense vowel in the English word beat is longer than the lax vowel
in bit.

Consonants may also differ from each other in length. Long consonants are
often called geminates, while short consonants are called singletons.
English does not really make regular use of consonant length, though there
are some marginal examples for some speakers, such as unnamed (with a
geminate alveolar nasal stop) versus unaimed (with a singleton alveolar nasal
stop). However, many other languages have widespread distinctions based on
consonant length.

For example, geminates and singletons are contrasted in Hindi (a Central

Indo-Aryan language of the Indo-European family, spoken in India). Hindi has
word pairs like (sammān) ‘honour’ (with a geminate bilabial nasal stop in the
middle of the word) versus ‘equal’ (with a singleton bilabial nasal stop in the
middle of the word). The pronunciation of these two Hindi words can be heard
in the following sound file, first with a geminate consonant, then with a
singleton consonant.

Multiple vowel qualities in sequence

Many vowels of the world’s spoken languages have a relatively stable
pronunciation from beginning to end. These kinds of stable vowel phones are
called monophthongs. However, just as there are dynamic consonant
phones (affricates), vowel phones may also change their articulation from
beginning to end. Most of these are diphthongs, which begin with one
specific articulation and shift quickly into another, as with the vowel in the
English word toy, which begins with a mid-back round quality but ends high,

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front, and unrounded. As with affricates, it can be difficult to determine
whether a given change in vowel quality is best treated as a true diphthong or
instead as a sequence of two separate monophthongs.

Some languages can even have triphthongs, which are vowel phones that
change from one vowel quality to another and then to a third, as
in rượu ‘alcohol’ in Vietnamese (a Viet-Muong language of the Austronesian
family, spoken in Vietnam and China). The word rượu has a vowel phone that
begins with a high central unrounded quality, then lowers to a mid-position,
and then finally ends in a high back position with rounding. The pronunciation
of this Vietnamese word can be heard in the following sound file.

Putting it all together!

There is not as much consistency in the order of descriptions for vowels as for
consonants. Perhaps the most common order is height – back-
ness – rounding, but rounding is sometimes given first instead, and though
height is usually given immediately before back-ness, these can also be
switched. Thus, the vowel in the English word bet might be described as a
mid-front unrounded vowel, or as an unrounded mid front vowel, or as a front
mid unrounded vowel, or as an unrounded front mid vowel. All of these would
be considered correct, and other combinations may be used.

When descriptions of nasality are needed, they are almost always placed after
the description of vowel quality. Thus, the vowel in the English
word bent might be described as a mid-front unrounded nasal vowel or as an
unrounded mid front nasal vowel, but rarely as a nasal mid front unrounded
vowel.

If descriptions of tenseness or length are also needed, these are often placed
before the other descriptions, but sometimes either or both may be placed
after vowel quality, but usually still before the position for the description for
nasality. Thus, the vowel in the English word bend could be described as a
long lax mid front unrounded nasal vowel, or as a lax mid front unrounded
long nasal vowel, or as an unrounded mid front long lax nasal vowel, or many
other combinations!

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