The Classification of Speech Sounds: Vowels and Consonants

Posted on Aug 29, 2024 in Geology

The Classification of Speech Sounds

Every speech sound is either a vowel or a consonant. A vowel is a voiced sound pronounced with an unobstructed flow of air.

The Consonant (r)

The consonant (r) has fallen from pronunciation in Standard English after vowels; that is, it has vocalized or become vocoid and disappeared. However, in many American dialects, it is retained as a retroflex consonant (one produced with the tip of the tongue curled back).

The Classification of Vowels

To describe the position of the tongue during the articulation of vowels, we use a trapezoid. This figure shows the effective area in the mouth where the tongue can move and change shape to produce different vowels. A vowel may be described as:

• Open or Closed
• Back or Front
• Rounded or Unrounded

If the tongue is held away from the roof of the mouth when a certain vowel is articulated, then that vowel is called open. If the tongue is held close to the roof of the mouth, then we speak of a closed vowel. We also use the terms half-open and half-closed.

If the front of the tongue is raised towards the roof of the mouth during the articulation of a vowel, it’s a front vowel; if the back of the tongue is raised, it’s a back vowel. Therefore, English (i:) and (ae) are front vowels, and (u:) is a back vowel. There are also central vowels, pronounced with the center of the tongue raised.

(i) represents a front unrounded vowel, and (y) stands for a front rounded vowel. Regarding lip-rounding in vowels, back vowels are normally rounded in all languages.

Diphthongs

A diphthong is a long vowel in which there is a single change of quality during one syllable; therefore, it is a kind of vowel-glide.

Closing diphthongs: ei, aI, ɔɪ, aʊ, əʊ.

Centripetal diphthongs: ɪə, eə, ʊə.

The term glide implies that the tongue starts in the position of one vowel and moves towards the position of another, passing through all the intermediate positions. If a diphthong is divided into two syllables, then we end up with a sequence of two vowels with a hiatus, not a smooth glide.

A diphthong may be described as being:

• Rising or Falling
• Centring, Closing, or Opening
• Wide or Narrow

If a diphthong is rising, the end is more prominent than the beginning; if it is falling, the beginning is more prominent. All nine major English diphthongs are falling (e.g., time, wait).

If a diphthong is centring, it ends in schwa (e.g., here, there, tour).

If a diphthong is closing, the tongue moves from a more open position to a closer one, and if it is opening, the reverse happens. The diphthongs (eI, aI, ɔɪ, aʊ, əʊ) are closing.

If the tongue makes a wide, sweeping movement, as in the diphthong (aI), in which there is a change from the very open position of (a) to the much closer position of (I), then we speak of a wide diphthong. If there is little tongue movement, as in (əʊ), the diphthong is narrow.

The Classification of Consonants

Three differences between vowels and consonants:

1. Articulatory

Vowels are articulated with a stricture of open approximation (no blockage to the airflow). Consonants are articulated with various degrees of stricture:

• Complete: Plosives /p, b, t, d, k, g, ʔ/
• Close Approximation: /f, v, θ, ð, s, z, ʃ, ʒ/
• Open Approximation: /j, w, l, r/

2. Acoustic

Vowels are more sonorous than consonants. Sonority is related to voicing. Voiced sounds are more sonorous than voiceless. The following English consonants are voiced: (b, d, g, v, ð, z, ʒ, dʒ, m, n, ŋ, l, r, j, w). The following English consonants are unvoiced: (p, t, k, f, θ, s, ʃ, tʃ, h).

3. Functional

3.1. Position in the syllable: Nucleus – Generally vowels, but liquids and nasals can also be the nucleus of a syllable. Liquids and nasals become syllabic consonants when replacing the schwa.

3.2. Obstruent vs. Sonorant

• Obstruent: Segments produced with enough obstruction to the airflow.
• Sonorant: Segments with no or little obstruction to the airflow.

Classification of Consonants

1. Voicing: Voiced vs. Voiceless

2. Place of Articulation:

• Bilabial: Upper lip + Lower lip (e.g., p, b, m)
• Labio-dental: Upper teeth + Lower lip (e.g., f, v)
• Dental: Tongue + Upper teeth (e.g., θ, ð)
• Alveolar: Tongue + Alveolar ridge (e.g., t, d, s, z, n, l)
• Post-alveolar: Tongue + Near the alveolar ridge (e.g., r)
• Palato-alveolar: Tongue + Hard palate (e.g., ʃ, ʒ, tʃ, dʒ)
• Palatal: Tongue + Hard palate (e.g., j)
• Velar: Back of the tongue + Soft palate (e.g., k, g, ŋ)
• Glottal: Glottis (e.g., h)

3. Manner of Articulation:

• Plosive: The air is completely blocked and then released, so a slight explosion is heard.
• Fricative: There is a narrowing of the air passage, causing audible friction.
• Affricate: The air is completely blocked and released slowly, so friction is heard.
• Nasal: The air passes through the nose.
• Approximant: The organs are not brought sufficiently close together to cause turbulence and produce audible friction.