Central Vowels in American English: Articulatory and Phonetic Properties

Central Vowels

Introduction to Central Vowels

Central vowels are a class of vowel sounds produced with the tongue positioned roughly in the center of the mouth. Their precise articulation can be challenging to describe due to variability in transcription and speaker differences. Central vowels are essential in phonetics and linguistics, especially in the study of American English pronunciation.

• Definition: Central vowels are articulated with the tongue body in a central position, neither front nor back.

• Importance: Understanding central vowels is crucial for accurate phonetic transcription and speech analysis.

• Context: Central vowels cannot be described without reference to other vowels in the quadrilateral vowel chart.

The Vowel Quadrilateral

The vowel quadrilateral is a visual representation of tongue position for vowel sounds. It is divided into front, central, and back regions, and further into high, mid, and low positions.

• Front Vowels: Tongue is positioned towards the front of the mouth (e.g., /i/, /e/).

• Central Vowels: Tongue is in the center (e.g., /ə/, /ʌ/, /ɝ/, /ɚ/).

• Back Vowels: Tongue is towards the back (e.g., /u/, /o/).

Front	Central	Back
i	ɨ	u
e	ə, ɜ	o
æ	ʌ, ɐ	ɑ

Additional info: The quadrilateral helps visualize the relationship between tongue height (high, mid, low) and tongue advancement (front, central, back).

Phonetic Properties of Central Vowels

/ə/ (Schwa) as in "about"

The schwa /ə/ is the most common central vowel in English, typically found in unstressed syllables.

• Articulatory Features: Central, lax, unrounded.

• Stress: Never occurs in a single-syllable word; always unstressed.

• Phonetic Context: Considered the unstressed counterpart to /ʌ/.

• Commonly referred to as: "Schwa".

Articulatory Summary:

• Lips: Unrounded

• Jaw: Closed to mid-open position

• Tongue: Ideally mid-central in isolated production, but position varies in connected speech

• Pharynx: Normally closed except in specific contexts

Examples of Graphemes for /ə/ (Schwa):

Grapheme	Example
u	untrue
o	cologne
a	machine
ai	villain
ia	parliament
io	nation
ou	jealous
i	merrily
oi	porpoise
e	happen
eo	surgeon

Example: The first vowel in "about" is a schwa.

/ʌ/ (Wedge) as in "bud"

The /ʌ/ vowel, also called the "wedge" or "caret," is a stressed, back-central, lax, and unrounded vowel. It is the stressed counterpart to the schwa.

• Articulatory Features: Back-central, lax, unrounded

• Stress: Occurs in stressed syllables, especially in one-syllable words

• Phonetic Context: Should not be confused with /ə/ in transcription

Articulatory Summary:

• Lips: Unrounded

• Jaw: Varies over a wide range but relatively open

• Tongue: Low-mid, back-central position, just up and forward from /ɑ/

• Pharynx: Normally closed except in specific contexts

Examples of Graphemes for /ʌ/:

Grapheme	Example
u	crumb
o	done
oo	flood
oe	does
ou	double

Example: The vowel in "bud" is /ʌ/.

Additional Central Vowels

/ɚ/ (Right-Hook Schwa) as in "butter"

/ɚ/ is a mid-central, lax, and rounded vowel, often called the "right-hook schwa." It is the unstressed, r-colored counterpart to /ɝ/.

• Articulatory Features: Rounded (but not always), closed to mid position

• Tongue: Mid-central, with bunching toward the palatal area

• Pharynx: Normally closed except in specific contexts

Examples of Graphemes for /ɚ/:

Grapheme	Example
or	labor
ar	lunar
ur	urbane
er	winner
ir	flirtatious
yr	martyr

Example: The final vowel in "butter" is /ɚ/.

/ɝ/ (Right-Hook Reversed Epsilon) as in "bird"

/ɝ/ is a mid-central, stressed, r-colored vowel, also called "right-hook reversed epsilon." It is the stressed counterpart to /ɚ/.

• Articulatory Features: Usually rounded, mid-open position

• Tongue: Mid-central, bunched in the palatal region

• Pharynx: Normally closed except in specific contexts

Examples of Graphemes for /ɝ/:

Grapheme	Example
or	word
ear	learn
er	perk
ir	shirt
ur	curt
yr	Myrtle

Example: The vowel in "bird" is /ɝ/.

Rhotic Vowels and Diphthongs

Rhoticity and R-Colored Vowels

Rhotic vowels are those that are influenced by a following /r/ sound, resulting in "r-coloring." This is common in American English and affects both central vowels and diphthongs.

• Rhotic Vowels: /ɚ/ and /ɝ/ are the main r-colored central vowels.

• Diphthongs: Vowels followed by /r/ can form diphthongs, such as /ɪr/ (fear), /ɛr/ (hair), /ɑr/ (star), /ɔr/ (court), /ʊr/ (tour).

Non-Rhotic	Rhotic
beer	burr
hair	her
star	stir
court	curt
lure	learn

Example: The difference between "beer" (/ɪr/) and "burr" (/ɝ/) is the presence of rhoticity.

Summary Table: Central Vowel Properties

Symbol	Name	Example Word	Stress	Rounded	Tongue Position
/ə/	Schwa	about	Unstressed	No	Mid-central
/ʌ/	Wedge	bud	Stressed	No	Low-mid, back-central
/ɚ/	Right-Hook Schwa	butter	Unstressed	Yes/No	Mid-central, r-colored
/ɝ/	Right-Hook Reversed Epsilon	bird	Stressed	Yes	Mid-central, r-colored

Key Concepts and Applications

• Phonetic Transcription: Accurate use of central vowel symbols is essential for representing American English pronunciation.

• Speech Pathology: Understanding central vowels aids in diagnosing and treating speech sound disorders.

• Language Learning: Learners of English benefit from recognizing central vowels in unstressed syllables and r-colored contexts.

Additional info: Central vowels are a major focus in both linguistics and speech-language pathology, as they are frequent in English and subject to variation across dialects and speakers.