Unit 3. The classification of speech sounds PDF

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Apuntes creados a partir de las clases del profesor Joan Carles Mora y el libro de recomendación de Brian Mott....

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3. THE CLASSIFICATION OF SPEECH SOUNDS 3.1. Introduction Every speech sound is either a vowel or a consonant. Vowel: is a voiced sound pronounced on an unobstructed flow of air. This means that during the articulation of a vowel there is no narrowing of the air passage anywhere in the oral cavity sufficient to create turbulence and cause audible friction. As soon as such friction comes into play, we no longer talk of a vowel sound but a consonant – a fricative consonant. If we go one stage further and completely block the passage of air at some point, then we create a plosive consonant when the air is released. The consonants in the English words big, pick and dot are all plosives. The consonants in the English words fish, save and thief are all fricatives. The consonants in the English words church and judge are called affricates, a kind of combination of plosive + fricative. The nasal sounds [m, n, ŋ] are also classified as consonants because, although the air passes through the nose when they are articulated, there is an obstruction at some point in the mouth. In the case of [m] the lips are brought together; [n] the tongue tip touches the alveoles; [ŋ] the back of the tongue makes contact with the velum. In this sense, they are like the plosives without the explosion, so they can be called nasal STOPS. If the articulators nearly make contact but do not actually constrict the air passage so as to produce a friction noise, then we produce what are known as approximants or frictionless continuants. In English these are [l, r, k, w]. We are dealing with degrees of stricture and the articulatory channel for an approximant is just sufficiently wider than that of a fricative for there to be no turbulence. Widening the articulatory channel of an approximant will produce a vowel; narrowing will produce a fricative consonant or, if obstruction is complete, a plosive or affricate. Apart from physiological differences between vowels and consonants, a distinction is also made on the basis of acoustic considerations: there is the question of elative sonority. Given the same length and degree of stress and constancy of intonation, some sounds have a timbre which makes them inherently more sonorous than others. Vowels are more sonorous than consonants, and open vowels (pronounced with the tongue low in the mouth) are mostly more prominent than close ones (pronounced with the 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 nasal are the most prominent, these being the most vowel-like. Although sounds have an inherent quality which we call tamber and which determines their different degrees of sonority or prominence, it must be remembered that the relative sonority of sounds depends on their length, stress and intonation –in the case of voiced sounds. By increasing the length and stress of a sound relative to another which is inherently more sonorous, we can make it more prominent. Similarly, intonation also plays an important role in making sounds stand out. Sounds can be made more prominent by raising their pitch.

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Another difference between vowels and consonants is their role in the syllable. The sounds we call vowels are usually the nucleus of the syllable. If we take the English word bet, we find it that we have three segments: [b] the onset of the syllable, [e] the syllabic nucleus and [t] the coda. The vowel [e] constitutes the peak of prominence of the syllable and is bounded on either side by less prominent sounds, the consonants [b] and [t]. Physiologically, this reduced prominence on either side of the vowel corresponds to a narrowing of the vocal tract. First the air is blocked for [b]; then there is a stretch when the vocal tract is relatively open, and this is followed by narrowing again, and therefore a decrease in sound, as the [t] is pronounced. Not all the sounds of a language fit tidily into this pattern. Some sounds are consonantal in some respects but vocalics in others. In fact, phoneticians prefer the terms contoid (consonantal) and vocoid (vocalic). The sound which are a kind of half-way house between vowels and consonants in English are the approximants [l, r, j, w] and the nasals [m, n, ŋ]. The segment [l] is contoid if we considers that the tongue tip is on the alveolar ridge, but vocoid if we consider the laterally released air – the air passes down the sides of the tongue, which are raised. The segment [r] if we consider the proximity of the tongue to the post-alveolar region. The nasals are contoid because of the obstruction in the mouth during their articulation, but vocoid from the point of view of air passing unobstructed through the nose The liquids, [r] and [l] and the nasals are relatively long, they can act like vowels in English words and form the syllabic nucleus. The consonant [r] has fallen from pronunciation Standard English after vowels, that is, it has vocalized or become vocoid and disappeared. 3.2. The classification of vowels These figures are intended to show the effective area in the mouth in which the tongue can move and change shape in order to produce different vowels. The dots represent the highest point of the tongue during the articulation of the vowels. A vowel may be describe as being: I. Open or Closed II. Back or Front III. Rounded or Unrounded (Labialized or Non-labialized) I. Open vowel = If the tongue is held away from the roof of the mouth when a certain vowel is articulated, so that the effective area of the oral cavity is large. Closed vowel = If the tongue is held close to the roof of the mouth. We also use the terms half-open and half-closed. II. Front vowel = If the front of the tongue is raised towards the roof of the mouth during the articulation of a vowel. Back vowel = If the back of the tongue is raised. There are also central vowels. Vowels pronounced with the centre of the tongue raised. In the word further both vowels are central /fᴈ:ᵭә/

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III. It can be said that back vowels are normally rounded. Vowels are articulated with backtongue raising have a graver tamber than those articulated with front-tongue raising. Now, when we push the lips forward, this elongates the oral cavity and also adds graveness to the sounds we produce. Thus, by combining backness and labialization, we are capitalizing on graveness and making our back vowels maximally distinct from our front vowels. Back unrounded vowels are also found but are not as common as other types. 3.3. Diphthongs A diphthong is a long vowel in which there is a single noticeable change of quality during one syllable. Therefore, it is a kind of vowel-glide or gliding vowel. The operative word in the definition is noticeable, as it is quite normal for long vowels to be slightly diphthongal owing to the fact that it is difficult to hold the tongue in one position for more than a brief moment. The term glide implies that the tongue starts in the position of one vowel and move towards the position of another, passing through all the intermediate positions on the way. Thus, although our transcription of diphthongs ([ai], [eI], etc) gives the impression that a diphthong is composed of two parts, this is not so; we are merely indicating the beginning point and potential ending point of the glide. The fact that a diphthong is a single glide also means that it is articulated in one syllable. A diphthong may be described as being: I. Rising or Falling II. Centring, Closing or Opening III. Wide or Narrow I. II.

III.

If a diphthong is rising, the end is more prominent than the beginning; if it is falling, the beginning is more prominent. If a diphthong is centring, it ends in schwa. In the articulation of such diphthongs there is movement from a more peripheral tongue position to a central one. 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 English diphthongs [escribirr p.67] are closing. If the tongue makes a wide, sweeping movement, as in the diphthong [aI], in which there is change from very open position of [a] to the much closer position of [I]. If there is a little tongue movement, as in [ ], the diphthong is called narrow.

3.4. Vowel systems The minimal vowel system consists of three vowels, so that optimum use is made of the vowel space in the mouth. The system has one very open vowel and two close vowels, one front and two back: i a u. Every language has a different system. 3.5. The Cardinal Vowels Before turning to the classification of consonants, it is necessary to mention the cardinal vowels. A well-trained phonetician can learn to hear and reproduce the cardinal vowels and then describe the vowels of any language accurately by relating them to these reference points. For example, English vowel no.2 [I] can be described as a half-close, front, unrounded vowel, but it

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can be located much more precisely if we say that it is slightly more retracted and a little bit closer than CV2. 3.6. The classification of consonants We know that the relevant distinctions made for vowels are: I the height of the tongue; II the part of the tongue which is raised, and, III the position of the lips. As vowels are by nature voiced, no reference is made to phonation. In the case of consonants, phonation is relevant and, because the air passage is impeded or made turbulent at some point, we also refer to this in our description. For consonants, therefore, we state: I. II. III.

Whether they are voiced or unvoiced (voiceless) The place of articulation The manner of articulation

I. Apart from use of the terms voiced or unvoiced, consonants have also been referred to as sonants or surds, and the labels lenis and fortis are also common. Voiced consonants are lenis because they are pronounced with relatively weak breath force owing to the proximity and vibration of the vocal folds during their articulation, which reduces the force of the air expelled from the lungs. Unvoiced consonants are fortis for the opposite reason: as the vocal folds are open when they are pronounced, there is little to break the force of the breath. II. The place of articulation of a consonant may be: -

Bilabial: the lips are brought together [p, b, m, w] Labio-dental: the top teeth touch the lower lip [f, v] Dental: the tongue touches the teeth [ , ] Alveolar: the tongue touches the gum ridge behind the teeth [t, d, n, l, s, z] Palatal: the tongue touches the palate [j] Velar: the tongue touches the velum [k, g, ] Uvular: the tongue touches the uvula Pharyngeal: the pharynx is constricted Glottal: the glottis is closed or narrowed [h, ?]

The roof of the mouth can be sub-divided to permit greater precision of description: postalveolar [ , ], palate-alveolar [ , , , ] (less frequently, alveolo-palatal), palatevelar. We may also refer, in the case of lingual articulations, to which part of the tongue makes contact with the roof of the mouth by using the prefixes apico-, blade- and dorso-. However, such detail is not usually necessary as there exist physiological constraints. In English [p, b, m] are bilabial; [f, v] are labio-dental; [ , ] are dental; [t, d, s, z, n, l] are alveolar; [r] is post-alveolar; [ , , , ] are palate-alveolar; [j] is palatal; [k, g, ] are velar; [h] is glottal. English [w] is produced with both labialization and back-tongue raising so, as it is coarticulated, it is described as labio-velar. Another co-articulated consonant is “dark” [l], which has linguo-alveolar contact accompanied by raising of the back of the tongue. III. According of their manner of articulation, consonants may be:

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-

Plosive: if the air is completely blocked and then released so that a slight explosion is heard Fricative: if there is narrowing of the air passage such as to cause audible friction. Affricate: if the air is completely blocked and then released slowly so that friction is heard. Nasal: if the air passes through the nose. Lateral: if the air is channelled down the sides of the tongue while the front of the tongue makes some kind of contact with the passive articulators. Vibrant: if an organ (usually the tongue) makes several rapid tapping movements against another organ. Tap: if the tongue makes a single rapid tapping movement against another organ. Approximant: if the organs are not brought sufficiently close together to cause turbulence and produce audible friction.

The English plosives are [p, b, t, d, k, g, ?] and they can also be called occlusive or stop. The English fricatives are [f, v, breathed.

,

The English affricates are [ edge.

]; the first is found in the word each, the second in the word

,

The English nasals are [m, n,

, s, z,

,

, h]. They can also be called spirants or

].

English has only one lateral consonant, [l], with the important velar allophone [ call “dark” [l].

], which we

Standard English has no vibrants or taps, although English people sometimes produce a bilabial vibrant (brrr!) to express that they are cold. Americans generally use a tap articulation for the [t] in words like butter [ ] and duty [ ]. The English approximants are [l, r, j, w]. As we seen above, [l] is also called a lateral. The typical Standard English [r] of words like red is a post-alveolar approximant, pronounced with the tip of the tongue slightly curled back, although a more fricative, devoiced variety is heard after [p, t, k], as in the words prince, tree and cross. [l] and [r] are sometimes called liquids. 3.7 Obstruents and sonorants The vowel-like nature of the nasals, liquids and semi-vowels makes it useful to have the umbrella terms obstruent and sonorant. The obstruent are the plosive, fricative and affricate consonants. The sonorants (or resonants) therefore comprise the vowels and diphthongs and the other consonant categories, which are the ones which have vowel-like qualities.

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