The Speech Mechanism: Sounds, Articulation, and Classification

Posted on Aug 29, 2024 in English

The Speech Apparatus

  • Made up of the organs (i.e., speech organs) of the body involved in producing speech sounds, from the lungs to the lips and nose:
    1. Lungs
    2. Trachea or windpipe
    3. Larynx or voicebox
    4. (Supraglottal) cavities or resonators
  • Pharynx/pharyngeal cavity
  • Nose/nasal cavity
  • Mouth/oral cavity
    1. Articulators (within the mouth)
  • Passive organs: teeth, hard palate + alveolar ridge, pharyngeal wall
  • Active organs: soft palate, lips, tongue, lower jaw

The Speech Mechanism

  • Speech sounds are normally produced as the air is forced outwards (egressive process).
  • Following Giegerich (1992:1), the production of speech sounds is the result of four processes:
    1. The initiation process: the lungs put the air stream into movement.
    2. The phonation process: when the air reaches the larynx, it makes the vocal folds vibrate or not.
    3. The oral-nasal process: the air is directed to the nose or mouth through the action of the velum.
    4. The articulation process: the different phonemes are produced due to the action of the articulators.

Definition of the Terms Vowel and Consonant

Every speech sound is either a vowel or a consonant.

A) From an Articulatory or Physiological Point of View:

Vowel: A sound in which there is no obstruction to the air-stream as it passes from the larynx to the lips and/or nostrils. Then, a vowel: a voiced sound pronounced on an unobstructed flow of air.

Consonant: A sound in which there is some kind of audible obstruction to the flow of air in the oral cavity. This obstruction can be of different types:

  1. Complete oral closure (plosives, affricates, and nasals)
  2. Intermittent closure (e.g., rolls such as Spanish “rr”)
  3. Partial oral closure (laterals)
  4. Close approximation (fricatives)
  • When the passage of air is completely blocked at some point: a plosive consonant, i.e., /p, t, k, b, d, g/ + [ʔ].
  • When there is friction: fricative consonant. e.g., /f, v/.
  • If there is a combination of a plosive plus a fricative: affricate. /tʃ/, /dʒ/, (as well as /tr/, /dr/).
    • Fricatives, plosives, and affricates are often called obstruents.
    • When the air passes through the nose when they are articulated, there is an obstruction at some point in the mouth: nasal /m, n, ŋ/
  • If the articulators nearly make contact but do not actually constrict the air passage so as to produce a friction noise: approximants or frictionless continuants: liquids /l, r/ and semivowels: /j, w/.
    • Umbrella term to cover nasals, liquids, and semi-vowels: sonorants or resonants.

B) From the Point of View of Distribution (= Different Positions the Sounds Can Occupy Within a Syllable):

  • Vowel: Sounds which occupy the central position in the syllable. The peak of prominence of the syllable. The consonants that surround it are less prominent.
  • Consonant: Sounds which occupy a marginal position within the syllable.
  • Not all sounds fit into this pattern. Some consonantal in some respects but vocalic in others: contoid and vocoid, for consonantal and vocalic sounds respectively. Sounds which are half-way between vowels and consonants are the approximants /l, r, j, w/ and the nasals /m, n, ŋ/.
    • Wau /w/, as in “well”, yod /j/, as in “yellow” are semi-vowels / semi-consonants.
      • Contoid: lack of stress; marginal position in the syllable.
      • Vocoids: articulation.

C) From the Point of View of Acoustics:

  • Vowels are more sonorous than consonants, and open vowels (tongue low in the mouth) are more prominent than close ones (tongue raised close to the roof of the mouth).
  • Voiced consonants have more prominence than unvoiced ones, and among the voiced consonants, the l-sounds and nasals are the most prominent.
  • There is little appreciable difference in prominence between the unvoiced consonants.

Criteria Used to Describe + Classify Speech Sounds

  • A full description of speech sounds: very lengthy; unnecessary information for our aim of language teaching. Articulatory and/or auditory information:
    • Consonants: described in terms of their articulation.
    • Vowels: auditory criterion together with some articulatory information (e.g., lip position). Cardinal Vowel System also used.

Description + Classification of Consonant Sounds

A) Pulmonic/Non-Pulmonic

  • Pulmonic: involving lung air.
  • Glottalic: involving pharynx air.
  • Velaric: involving mouth air.

B) Egressive/Ingressive

  • Egressive sounds: sounds produced with the out-going stream of air. Most sounds in English.
  • Ingressive sounds: made as we are breathing in, which we sometimes use when sobbing, gasping for breath, expressing sympathy, or pain.

C) Voiced/Voiceless

  • Voiced sounds: The vocal folds get into contact and vibrate.
    • There are 15 voiced consonants: /b, d, g, v, ð, z, ʒ, θ, l, r, m, n, dʒ, j, w/ plus all the vocalic phonemes, as vowels are always voiced in English.
  • Voiceless sounds: Vocal folds are held wide apart.
    • There are 9 voiceless consonants: /p, t, k, f, ʃ, s, ð, tʃ, h/.

According to the degree of articulatory strength (breath and muscular effort):

  • Lenis consonants: produced with a relatively weak degree of articulatory effort.
  • Fortis consonants: strong degree of articulatory strength. Only voiceless sounds.

D) Oral/Nasal

  • Oral sounds: Velum raised. Pressed against the back of the pharynx.
  • Nasal sounds: Velum lowered. The air goes out through the mouth.

E) Place or Zone of Articulation → see diagrams (pp.17-20)

  • Bilabial: The two lips are brought together: /p, b, m/.
    • Labio-dental: The lower lip articulates with the upper teeth: /f, v/.
    • Dental: The tongue tip is raised against the upper teeth: /θ, ð/.
  • Alveolar: The blade of the tongue articulates with the alveolar or gum ridge: /t, d, l, n, s, z/.
  • Post-alveolar: The tip of the tongue is raised towards the back of the alveolar ridge: /r, tr, dr/.
  • Palato-alveolar: A raising of the front of the tongue towards the hard palate: /ʃ, ʒ, tʃ, dʒ/.
    • Palatal: Front of the tongue articulates with the hard palate: /j/.
  • Velar: The back of the tongue articulates with the soft palate: /k, g, ŋ/.
  • Glottal: Sudden opening of the glottis or abrupt closure of the glottis to block the airstream. Obstruction or narrowing between the vocal cords.
    • For the glottal stop, i.e., [ʔ] vocal cords close: London pronunciation of “matter”.
    • In /h/, the vocal cords are open.
  • Labio-velar or labial-velar. Bilabial approximant and a (dorso-)velar approximant pronounced simultaneously: /w/.
  • Retroflex. Whereas /r/ is not generally pronounced in final position or before consonants in standard British English, in other varieties (American, Scottish, Western British accents) there is an /r/ in this position.

F) Manner of Articulation

Type of closure or narrowing at the point of articulation.

Complete Closure:

  • Plosive/stop/occlusive: /p, t, k, b, d, g/ and [ʔ].
  • Affricate: a plosive immediately followed by a fricative: /tʃ, dʒ/.
  • Nasal: the air escapes through the nose: /m, n, ŋ/.

Partial Closure:

  • Lateral: /l/

Narrowing:

  • Fricative. Friction is produced though not closure: /f, v, θ, ð, s, z, ʃ, ʒ, h/.
  • Approximant: /l, r, j, w/.

Two further possibilities (not in Standard English):

  • Vibrant/roll: a bilabial vibrant (brrr!): cold.
  • Tap/flap: alveolar tap [ɾ], as in a typical US pronunciation of Betty.

The Cardinal Vowels

  • Set of vowel qualities that are standard reference points for describing the vowels in any language. Not real vowels. Reference system.
  • A cardinal vowel is any of the reference vowels recognized in the cardinal vowel system. The quality of speech sounds is identified by reference to the nearest cardinal vowel.
  • The system is based on two selected vowel sounds:
    1. The front vowel [i]. The closest and frontest possible vowel. By gradually lowering the tongue, three more front vowels are produced: [e], [ε], [a].
    2. The back vowel [ɑ]. The openest and backest vowel. By gradually raising the tongue, three more back vowels are produced: [ɔ], [o], [u].
  • Four levels of tongue heights: the highest position (i.e., close/high); the lowest position (i.e., open/low); and two intermediate levels (i.e., close-mid/half-close and open-mid/half-open).

Vowel Sounds. Classification

  • Vowel sounds are produced by an egressive air-stream escaping unimpededly over the centre of the tongue with no contact being made between the articulators.
  • Their quality is produced in different ways:
    • By raising a certain part of the tongue (front, centre, or back) to different levels.
    • By modifying the shape of the lips, spreading or rounding them in different degrees.
  • The first type of information (tongue positions), is the one most frequently used to describe vowels and the one reflected in the English Vowel Chart.
  • All English (and Spanish) vowels: pulmonic, egressive, voiced, and oral.