Mechanisms of speech sound production
IN CLASSIFYING CONSONANTS AS DIFFERENT FROM VOWELS
Mechanisms of speech sound production make vowels different from consonants. There are 4 main mechanisms that take part in the production of consonants: the power mechanism, the vibrator mechanism, the resonator mechanism and the obstructer mechanism. But the obstructer mechanism doesn’t take part in the production of vowels. From the auditory point of view a vowel is voice or tone, and the obstructer mechanism creates noise.
The leading mechanism for the production of vowels is the resonator mechanism.
The leading mechanism for the production of consonants is the obstructer mechanism.
Power mechanism
It differentiates the force of exhalation (which is weaker for vowels in comparison with consonants) and produces the air stream. The air stream makes the vocal cords vibrate and fills the resonators with air to produce sounds. The PM also differentiates muscular tension and takes part in the mechanism of aspiration (see the vibrator mechanism).
Vowels. 1) The muscular tension is diffused. 2) The PM modifies the force of the stream of air, accordingly, we differentiate between tense / i:, u:/ and lax /all the rest/ vowels.
Consonants. 1) The muscular tension is concentrated in the point of articulation. 2) The PM makes the vocal cords vibrate for voiced consonants, sonorants and semi-vowels and keeps the vocal cords apart for voiceless consonants. 3) According to the force of exhalation, consonants are subdivided into fortis /all voiceless consonants: p, t, k, h, etc. = we need more effort to produce them!/ and lenis /all voiced consonants: b, d, etc./
Vibrator mechanism
It is responsible for the vibration of the vocal cords which gives voice or tone. It also differentiates duration of vibration of the vocal cords.
Vowels. According to the duration of vibration of the vocal cords, we single out long / i:. u:, a:, o:, ә:/ and short /all the rest/ vowels. The length is historical.
According to the speed (=rate) of vibration of the vocal cords, there are vowels different in pitch. The more rapid the rate of vibration, the higher is the pitch.
Consonants. 1) The VM creates voice for voiced consonants, sonorants, semi-vowels. 2) The VM gives the mechanism of aspiration. Aspiration is an additional puff of air for some consonant. There appear postponed vibrations after the release of / p, t, k, t∫ /, the vocal cords don’t start to vibrate immediately. There’s a gap within which a puff of air is given to the consonants. And only after the puff of air has been supplied, the vocal cords start vibrating for the following vowel. So there are aspirated and non-aspirated consonants.
Resonator mechanism
Vowels. !leading mechanism! In the production of vowels it involves the work of the mouth resonator only. The RM is the leading mechanism in the production of vowels as it specifies tone creating different vowels. The mouth resonator changes its shape, size and volume making all vowels different. The position of the lips and the movements of the tongue modify the shape, size and volume of the mouth resonator.
According to the horizontal movement of the tongue, the English vowels fall into:
- front / i:, e, æ /
- front-retracted / I /
- central / ә , ә: /
- back / o, o:, u:/
- back-advanced / a:, u, /\ /
According to the vertical movement of the tongue, the English vowels are subdivided into 3 classes. Each of these classes is further subdivided into 2 variations – narrow and broad.
| Close = high | half-open = mid | open = low | |
| narrow | i: , u: | e , ә: | o: , /\ |
| broad | I , u | ә | æ , a: , o |
According to the position of the lips, the English vowels are classified into rounded / o, o:, u, u: / and unrounded /all the rest/.
According to the stability of articulation (= the stability of the shape, size and volume of the mouth resonator) the English vowels are divided into: 1) 10 monophthongs (the mouth resonator doesn’t change its properties), 2) 8 diphthongs (during their pronunciation the tongue and the lips move from one vowel position to another with the result that the properties of the mouth resonator change) and 3) 2 diphthongoids / i:, u:/ (diphthongoid is a vowel sound intermediate in character between a monophthong and a diphthong. Its elements are very close to each other, and the tongue and/ or the lips move an extremely short distance between them).
Consonants. In the production of consonants the RM can involve the work of 2 resonators: mouth resonator or nasal resonator. It provides the possibility for changing of the resonator (its shape, size, volume) because the soft palate can be raised (oral sounds) or lowered (nasal sounds).
Oral consonants: all voiced and voiceless consonants + 1 sonorant / l /
Nasal consonants : sonorants / m, n, ŋ /
The mouth resonator is the place of obstruction for the production of consonants.
Obstructer mechanism
Vowels. From the articulatory point of view, the OM doesn’t take part in the production of vowels. When vowels are produced muscular tension is diffused = distributed evenly in the active organ of articulation so that not a single part of it is raised higher to create an obstruction. So the air passes through the mouth cavity unimpeded.
Consonants. !leading mechanism! When consonants are produced, muscular tension is concentrated in one point (= in the point of articulation). So this part of the articulatory organ rises higher creating an obstruction. The stream of air overcomes this obstruction creating noise.
The quality of a consonant sound depends on the kind of the noise produced.
There are several principles according to which consonants are classified.
1) According to the active organ of obstruction:
- labial. Labial consonants can be a) bilabial (when lips are brought together): /p, b, m, w/ and b) labio-dental (they are articulated with the lower lip against the upper teeth): / f, v/.
- lingual. Lingual consonants are subdivided into forelingual, mediolingual / j /, backlingual /k, g, ŋ /. According to the position of the tip of the tongue, forelingual consonants may be: dorsal (not in English), apical (the tip of the tongue is against the teeth-ridge) / t, d, n, l, s, z, θ, ð/ and cacuminal = retroflexed (the tip of the tongue is raised leaving a spoon-shaped cavity in the middle part of the tongue, it is raised against the back part of the teeth-ridge) / r /.
- pharyngeal (consonants are articulated in the pharynx: its walls get slightly narrow while the root of the tongue moves towards the back wall of the pharynx) / h /.
2) According to the place of obstruction:
- labial (see above): bilabial + labio-dental
- dental (the tip of the tongue is against the upper teeth): / θ, ð /
- alveolar (the tip of the tongue is against the teeth-ridge): / t, d, n, l, s, z /
- palatal (the middle part of the tongue is against the hard palate): / j /
- palato-alveolar (the tip of the tongue is against the teeth-ridge or the back part of it, while the middle of the tongue is raised in the direction of the hard palate): / ∫, 3 (=ж), t∫, d3 (= дж)/
- postalveolar: / r /
- velar (the back of the tongue is against the soft palate): /k, g, ŋ /.
3) According to the type of obstruction (= the manner of production of noise):
- occlusive = complete (the air-passage through the mouth is completely blocked). Occlusive consonants can be
1) plosive consonant = stops (from the auditory point of view the obstruction ends with a kind of explosion) : / p, b, t, d, k, g /
2) nasal sonorants (the air-passage through the mouth is completely blocked, while the soft palate is lowered so that the air can pass through the nasal cavity): / m, n, ŋ /.
- constrictive (the air-passage isn’t blocked completely, it’s narrowed so that an incomplete obstruction occurs). According to the size of the narrowing constrictive consonants are divided into:
1) fricative consonants (the air-passage is rather narrow, the air passes through a narrowing and produces audible friction): / f, v, s, z, θ, ð, ∫, 3 (=ж), h /
2) constrictive sonorants (the air-passage is rather wide, the air passes through the narrowing and doesn’t produce audible friction). Here tone prevails over noise. Constrictive sonorants can be a) medial (the air-passage is narrowed at the sides of the tongue but it’s open in the middle): /w, r, j / b) lateral (the tip of the tongue is against the teeth-ridge, the sides of the tongue are lowered and the air-passage is open along them): / l /.
- occlusive-constricted = affricates (the stream of air is first stopped and then the closure is released with friction): / t∫, d3 (= дж)/.
Conclusion: we have proved that depending on the mechanisms of speech sound production there are different approaches to classifying vowels and consonants. Different types of vowels and consonants rely on the essential distinctions between vowels and consonants.
General information: in English there are 20 (or 21 [oә]) vowels and 24 (or 25 [/\/\ = чит. «хв»]) consonants.