Phonetics - The Study of Speech Sounds-overview.

Phonetics - The Study of Speech Sounds

Phonetics has been defined as the science of speech sounds. It is a branch of linguistics and deals with the sounds produced by human beings in their speech behaviour. In speaking trial listening a complex of activities is involved : there is the production of speech which is the result of simultaneous activities of several body organs.

These activities are aimed at creating disturbances in the air. The inhaled air acts as source of energy setting the outside air vibrating so that the sound thus generated is carried along to the ears of the listener. The auditory process is set in motion which is again a complicated process involving auditory organs; perception of speech segments which involves discarding the non-significant features from the significant or distinctive features and perceiving only those that are meaningful. ‘Even a single speech sound combines a large number of distinctive features which provide the information on which an auditor bases recognition of the sound’ (Tiffany-Carrell). It is like retrieving a small visual image from a crowd of intricate details. But the brain can quickly decode the incoming signals that have been encoded by the speakers. ‘Physical energy in the form of sensory nerve impulses reaches the brain’, the brain circuitry is understood to organise them into percepts which are the basis of recognition. Obviously, a complex of multiple factors in the form of the listeners’ interest, his social background, intellectual level, pas! experience and other parameters play an active and significant role in the perception level, and the interpretation is made accordingly.

We thus observe that speech act encompasses intricate movements and activities that occur on different planes, some of them simultaneously and at incredible speed. We ate so used to speaking in a natural effortless manner, that we hardly give attention to the complex nature of speech production and speech perception.

Branches of Linguistics

Phonetics    has three major branches:

1)   Articulatory Phonetics

2)   Auditory Phonetics

3)   Acoustic Phonetics

Articulatory phonetics is also known as physiological phonetics; and auditory phonetics is known by the name perceptual phonetics.

Articulatory Phonetics

This branch of phonetics recognises that there is speech producing mechanism in human beings. ‘The ‘apparatus’ that produces speech sounds is situated within the human body. However, it must be clear that there is no separate ‘apparatus’ exclusively used for generating speech sounds. Speech is, infact, an overlaid function in that human beings utilize in a special way organs which are part of the respiratory and digestive system. Man uses those organs for speaking which already serve other biological needs. Thus lips, teeth, tongue, hard palate, soft palate, trachea, lungs - all these organs used in speech production have different basic biological functions. In the process of cultural evolution, man devised ways of utilizing these organs and parts thereof (such as the tip, blade, front, centre, back of the tongue alongwith the corresponding areas or points in the roof of mouth or hard palate) for verbal communication.

Besides( these the airstream that goes in and out of the lungs forms the basis of speech; that is, speech is based en the outgoing airstream. Articulatory phonetics studies how the outgoing airstream is regulated along the vocal tract to form various speech sounds.

Auditory Phonetics

This branch of phonetics studies how speech sounds are heard and perceived. This galls for a close study of the psychology of perception on the one hand, and the mechanism of the neuro-muscular circuitry on the other.

Hearing is a very intricate process; it implies ‘interpreting the physical description of actual or proposed signals in terms of the auditory sensations which the signals would create if impressed upon the ear’ (French). Acoustic signals generate a ‘complex chain of physical disturbances within the auditory system’. The brain receives signal about these physical disturbances; in the brain are caused other disturbances - physical counterparts of the sensations. It is necessary to establish correlation between the auditory signals and their interpretation in terms of the disturbances in the brain. It is a challenging task, one can say that not much headway has been made in unravelling the complex pattern of the course charted by the speech signals through the auditory system into the neuro-muscular processes. However, we can divide the whole process into three stages:

i)    the physical aspect of die auditory system

ii)   recognition of the essential characteristics of hearing.

iii)  interpreting auditory sensations, their attributes and their relation to the signals.

The physical aspect of die auditory system involves a detailed description of the external, middle and inner ear (also known as Cochlea), and the auditory receptive centres of tic bran, the neural network. This also takes into account ‘translating acoustic signals into auditory sensations’ which begins with the transfer of pressure variation of sound waves to the fluids in the inner ear. The inner ear analyses these vibrations and encodes them into ‘neural pulses of elctrochemical activity’. The inner ear is connected to the auditory receptive centres by the auditory nerve which carries these pulses. The auditory centres are correspondingly stimulated. But there is a difference between the liaises and the actual sensations in the neural centres that ate thus generated.

The basic characteristics of healing include such features as loudness, absolute sensitivity, frequency tones, ‘masking’ or the elimination of the subjective traces of one of the two or more sounds; that the ear is exposed to, pitch etc. Interpreting, the auditory sensations into their physical signals poses serious problems. The auditory sensations do lint offer a featly, palpable pattern that can satisfactorily be described Sound signals may be composed of a variety of components - horn bits of ‘transients’ to sounds of longer duration; from single unit tones to multiple segment complexes; Bonn ones having a constant pattern to continually changing frequencies. It is not necessary that the auditory sensation would reflect the identical occurrences of these sound signals. In the complex sound patterns, their ‘separate components may retain the identity in the resulting sensation’ or may produce an entirely new sensation. Signals of varying frequencies may produce a study pattern of sensations or separate sensations. Composition of the human brain plays a crucial role in this regard. It poses difficulties in the way of interpretation. Many signals are highly complex and can only be described in mathematical terms. However, such descriptions do not have any relevance to phonetics and must, therefore, be ignored.

Acoustic Phonetics

Acoustic phonetics is the study of the physical properties of speech sounds such as frequency and amplitude in their transmission. Acoustic phoneticians analyse the speech waves with the help of instruments, attempt to describe the physical properties of the stream of sound issues forth from the mouth of a speaker.

It is in the field of acoustic phonetics that the most sulking developments have taken place since the Second World War. Complex sound waves produced in speech can be analysed into their component frequencies and relative amplitudes. Considerable progress has also been made in speech-synthesis. Acoustic analysis has confirmed (if confirmation was needed) that speech is not made up of a sequence of discrete sounds. The articulatory features of rounding of voice, of nasality, of obstruction and of friction can also be identified acoustically. Acoustic phonetics achieved a good deal of success in matters of the study of the n vowels, but regarding consonants it has not reached final conclusions.

Articulators

We shall now consider the organs which are used in articulation. All speech organs are known as articulators. They are broadly divided into two categories :

a)   Mobile or active articulators

b)   Fixed or passive articulators

We have already noted that there is perceptibly significant mobility in the laryngeal and pharyngeal regions. In fact, the whole of sub-laryngeal area is active in speech production. However, there are more noticeable movements in the larynx and areas immediately above it. The throat forms a crucial factor in determining resonance. The length of the pharyngeal resonator can be changed by muscular actions which raise and lower the larynx. Among the mobile or active articulators the centrally important one is the tongue. It is extremely flexible and mobile. The other two mobile articulators are the lower jaw (mandible) which can move both vertically and horizontally to change the phonetic qualities of sounds, and the lips; they can be rounded or spread, brought closer to the upper teeth or simply held neutrally.

The fixed or passive articulators are include the roof of the mouth. This is dome-shaped, hard and bony. It is known as the hard palate. The hard palate and the teeth play a necessary, although passive role in articulation. The bony palate forms the anterior part of the roof of mouth, separating the oral cavity from the nasal passage. The hard palate terminates in the soft palate which is muscular. This is also called velum or velum palatinum which forms the posterior section of the roof  of the mouth, separating the mouth cavity from nasopharynx. The velum can be lowered or raised for opening or closing the nasopharyngeal passage. We shall see this in detail in the section dealing with nasal sounds.

The upper teeth also participate in articulatory process, with the active articulators coming into contact with them to form various constrictions, thus modifying the airstream and producing different speech sounds.

We shall now separately consider in detail each one of these articulators. First let us look at the active articulators.

Active Articulators

The main role of the active articulators is to actively interfere with the outgoing airstream and modify it to produce various types of speech sounds. This is done either by approximating (forming a constriction) or coming into full contact with the passive articulators (forming complete stoppage). We have seen the functioning of the larynx, glottis and vocal cords in earlier sections. Now we shall take a look at the oropharyngeal articulators that are situated in the mouth.

Tongue

The most active of articulators is the tongue. It shows an amazing range of adjustments and movements mainly because it is made of two groups of muscles, intrinsic ones are fibres of the longitudinal, transverse and verticalis lingual musceles. These muscles are within the tongue and mainly responsible for changes in its shape. They blend with the extrinsic muscles which originate outside of the tongue. Their function determines the position and movement of the tongue. ‘The tongue is an organ of taste, and used for chewing and swallowing activities... On the basis of its great flexibility and motility, the secondary function of articulation has been super-imposed’. (G.E. Arnold)

It has been divided into the following major parts on the surface along its length.

i)    apex or tip

ii)   blade

iii)  front

iv)  back or dorsum

v)   root

The sides of the tongue can also be used in speech, these are known as margin. For lateral sounds the sides are raised enough for the airstream to create turbulence and escape continuously. The tip can be raised and curled backwards letting the passing airstream to vibrate it. This produces retroflex sounds of various types.

Lower lip: The lower lip is a mobile articulator which can be used for many oral configurations. With the upper lip it can form various degrees of rounding that produce different vowels. It can bring about complete oral occlusion with the upper lip which produces bilabial sounds, plosives and in many languages fricatives also. When the lower lip comes into contact with upper teeth, we hear fricative sounds (labio-dental).

Passive Articulators

Passive or immobile articulators cannot be moved about, but perform a v cry crucial role in speech production. The mobile organs approximate them, i.e. come close enough to affect the shape of the outgoing column of air, or form a complete closure by coming into full contact with them.

These organs are mostly located in the upper part of the mouth, beginning in front with the upper lip, upper teeth, the gum ridge or alveolum, hard palate, the soft palate, just behind the hard palate and the back wall of the throat (pharynx).

Upper lip : Though upper lip is not a rigid organ and can be moved, in speech production it is not used as a mobile articulator; rather the lower lip reaches up to create various constrictions with it. Therefore, it has been classified as a passive articulator.

Upper teeth: The row of upper teeth functions as the passive articulator. Tongue-tip and blade as well as the lower lip form constriction with them. The active organs can do so either with the edges of the teeth or the back of them. Dental class of sounds is produced in this manner. Upper teeth are also involved in the production of the fricative sounds, called labio-dentals in which the lower lip approximates them to form a slit through which the air escapes creating friction noise.

Gum ridge: Just behind the upper teeth is located alveolar or gum ridge. The mobile speech organs - various parts of the tongue reach it to form either a narrow stricture or a complete closure. Hindi /d/ and /t/ and their aspirated counterparts are dental stops. But English /0/ in thin and /ð/ in this are fricatives.

Hard Palate: Behind the alveolum or gum ridge begins the hard palate which forms the major part of the oral arch or roof of the mouth. We already possess an idea of its formation. It is made of the horizontal plates of bone which terminate in the soft palate. ‘Some part of both the hard and the soft palates serves as a point of contact or near-contact for the tongue in the production of a number of speech sounds’. It can be divided into parts or areas where the tongue makes contact. Phonetic quality is changed according to the point at which the hard palate is approximated by the tongue. These sounds are recognised as palatal. These are further classified according to which part of the tongue comes into contact with the precise palatal area. For example, we can produce palato-alveolar sounds by bringing the tip of the tongue to touch the extreme front of the hard palate or the place lying between the gum-ridge and the palate. Alveo-palatal area lies further back of the region just mentioned; palatal the slope of the hard palate and domal is the dome of it. Classification is largely a matter of convenience and practical need of the particular language. Not all the languages or dialects make use of all the classification criteria. What is suggested here is that precise classifications are possible.

Soft Palate: This is recognised as the fixed articulator though it can he moved, being a soft and flexible organ. The principal action of soft place consists of opening the naso-pharyngeal cavity by lowering itself. When it is lowered, the oral passage is closed off and the outgoing airstream passes through the nose, sounds produced in this manner are identified as nasals. /m/, /n/, /h/ and the nasalised vowels are of this type. For opening the oral passage and allowing the air a free passage through it, the soft palate is raised. Soft palate thus acts as a valve. The back of the tongue or derssum makes contact with the velum to produce either frictional sounds or stops. These stops are known as velar stops /k/, /g/. Retroflex sounds can also be produced by bringing the underside of the tongue tip to touch the velum.

Uvula

The soft palate terminates into a piece of flesh which dangles over the pharyngeal passage. This is called uvula. It is a ‘small flexible appendage hanging down from the posterior edge of the velum, (Gleason). It can be vibrated by the outgoing breath-stream, to produce uvular sound, particularly uvular trills. Some languages use these sounds as phonemes.

Pharynx: The posterior wall of the pharynx is used for producing speech. In the front are the base of the tongue, the palate, and the two openings leading to the nasal and oral passages. This area can be divided into three parts : the hypopharynx behind the tongue; the mesopharynx, behind the velum, and nasopharynx behind the nose. In the mesopharynx area are to be found the crossing of the alimentary and respiratory canals. The pharynx serves as a resonator for the voice. Widening of the pharynx promotes resonance and makes the tones full, dark, strong and resonant; narrowing tends to make them thin, sharp, dampened, and throaty’ (Arnold). Besides, the root of the tongue can also be made to come into contact with the pharyngeal wall and produce certain types of fricatives and stops. Below are discussed certain processes of speech production. These are generally used by languages all over the world.

Labiabialization

This is a process in which the lips play an active part in various ways. They come together to form various stages or degrees of rounding which is a crucial factor in producing back vowels /u/, /o/, / /, as in shoe, shore, and .a. The two lips are joined together for the pronunciation of the plosive sounds /p/, /b/; and the voiced nasal continuant /m/. The lower lip is raised approximate the edge of the upper teeth for the fricatives /f/, /v/. For the semi-vowel /w/ again there is a noticeable lip-rounding. Bilabial fricatives are not uncommon. In the African language Tshiluba this is used. Even a bilabial trill is heard in some languages.

Polatalization: In palatalization the tongue approximates the hard palate leaving only a narrow space through which the airstream passes producing friction noise; or the tongue may form complete occlusion and then gradually withdraw, creating a turbulence of air due to the breath-stream escaping through the space slowly being allowed to form. This is how the sound in jar /dзa:/ and chair /tòe∂/ is pronounced.

Velarization: Velar sounds are produced by this process. The back of the tongue either approximates or forms total occlusion for articulating certain types of stop and fricative sounds. The velar sounds are /k/ and /g/ in English. /h/ is a velar nasal heard in such words as king, sing, inquest and conquer.

Glottalization: The space between the vocal cords is called glottis. If the vocal cords are brought together taut and released with a ‘popping’ action, the resultant sound will be heard as a ‘glottal stop’, symbolised as /?/. We
create a glottal closure when we have to lift something heavy. In this act adequate pressure of air is, built up in sub- laryngeal region to provide enough strength. Immediately after doing the work a heavy amount of breath is forcefully released, accompanied by a glottal sound. In rapid conversation often this is used in the form of ‘catch’ in the throat. The Cockney speech of London contains quite a generous share of this sound takes place of certain dropped sounds, for example, in butter pronounced bu’er /b^?/ or letter /le?ә/. Glottal stops are phonemic in some
languages. Glottal fricatives are used in Scottish language and its regional dialects. These are symbolised as [h] and [h]. In English /h/ as used in house, he, her, horse is a glottal fricative. The Scottish word loch ‘lake’ contains the glottal fricative.

Nasalisation : This is a process whereby we produce nasal sounds or nasalised vowels. In articulating these sounds, the soft palate is lowered to close off the oral passage and direct the airstream through nasal cavity. In another case, the air is allowed to go into both the oral and the nasal cavities, but the active articulators check it in the mouth. For /m/ two lips come together to form a closure, and channelise the air flow, through the nose. Similarly, for /n/ the tip of the tongue comes into contact with the back of the upper teeth and forms a closure. ‘Although the vocal tract is blocked at one point, the breath-stream flows outward through what has been called a secondary aperture consisting of the nasal airway. Acoustically, the physical conditions which impart the perceived nasal quality to these sounds are sometimes referred to as cul de sac resonance, where a relatively small cavity, the nasal resonator, is coupled to a large cavity, the oropharyngeal cavity (Tiffany-Carrell). Nasals are also classed as resonants or continuants.

Voicing : It is an articulatory process in which the vocal flaps are set in vibration by the outgoing column of air. During voicing, the vocal cords are brought close enough to hold them taut and the airstream vibrates them in rapid succession. There is as a result, quick opening and closing of these vocal cords several times a second. Sounds can be produced without the vibration of the vocal cords. Such sounds are called unvoiced or voiceless sounds; sounds produced with the cords in vibration are called voiced sounds. How can one ascertain whether a sound is voiced or not? There are simple methods to do so. If we cup our ears and pronounce a voiced sound we can hear a ‘buzzing’ noise, from the time we actually get ready for it. /z/ in zoo and /dз/ in judge or jam are voiced sounds. Another simple method is to put a finger on the front of the voice box or ‘adams apple’ and say these sounds - a distinct sensation of noise can be felt which is missing when we pronounce an unvoiced sound. In English we produce /g/, /b/, /d/, /dз/, /v/, /z/, /з/, /ð/, /m/, /n/, /h/, /l/, /w/, /r/ and all the vowels with voicing. These are voiced sounds. The voiceless sounds are /k/, /p/, /t/, /tò/, /f/, /s/, /ò/, /q/.

Frequency of the vocal cords vibration is also related to the low and high tones, pitch level and voice amplitude, but we shall consider this in a later section. We must bear in mind at this stage that voicing or vibration of the vocal cords has a crucial function in speech production. It forms a basic factor in the fundamental classification of speech sounds into two functional categories, the voiced and the voiceless ones.

Manner of Articulation

The manner or way in which the outgoing air-stream is interfered with determines the manner of articulation. A sound can be described in this light. The airstream may completely be stopped and released with force producing a plosive or stop sound. The occlusion may occur anywhere between larynx and the two lips; or the passage of air may be constricted enough for it to produce audible friction. The sound thus produced is called fricative. According to the manner of articulation sounds are classified into smaller classes as stops, fricatives, affricates, nasals, laterals, trills or flaps and semivowels. These constitute the larger class of consonants. For the complete description both the point/place and manner of articulation are taken into consideration.

Fortis and Lenis

In producing speech sounds a great deal of muscular energy is involved. Some of the sounds need greater energy than others. Voiceless sounds are the examples of sound pronounced with greater energy. The dichotomy signifies grouping of sounds according to the degree of muscular tension. ‘The former tend to be voiceless, the latter voiced, but considerable contextual modification of these qualities are possible, especially as a result of accentual features’ (L.F. Brasnalian). English /p/, /t/, and /k/ are the examples of sounds pronounced with greater effort and breath. ‘In German fortis articulation such as t, k, f are distinctly voiceless, in American English, on the other hand, especially between vowels, these sounds are commonly voiced throughout their duration’.

In lenis, the muscular, energy is markedly decreased and so also breath. Mostly voiced sounds are lenis such as /b/, /d/, /z/, /v/, /з/, etc.

Voiced and Voiceless Sounds

We have already noted the voicing mechanism. The division of speech sounds into the voiced and the voiceless ones is of great importance in phonetics. The beginners should familiarise themselves with the vibrations felt during the production of voiced sounds.

Description of Speech Sounds

Speech Sounds are divided into two main groups: (1) consonants, and (2) vowels.

Consonants:

A description of consonants, according to A.C. Gimson, must provide answers to the following questions:

(i)           Is the air-stream set in motion by the lungs or by some other means? (pulmonic or non-pulmonic).

(ii)         Is the air-stream forced outwards or sucked inwards? (egressive or ingressive)

(iii)       Do the vocal cords vibrate or not? (voiced or voiceless).

(iv)        Is the soft palate raised or lowered? Or, does the air pass through the oral cavity (mouth) or the nasal cavity (nose)?

(v)          At what point or points and between what organs does the closure or narrowing take place? (Place of articulation).

(vi)        What is the type of closure or narrowing at the point of articu­lation? (Manner of articulation).

Thus the description of a consonant will include five kinds of infor­mation : (1) the nature of the air-stream mechanism; (2) the state of the glottis; (3) the position of soft palate (velum); (4) the articulators in­volved; and (5) the nature of the ‘stricture’.

The Nature of the Air-stream Mechanism. Most speech sounds and all normal English sounds are made with an egressive pul­monic air-stream, e.g., the air pushed out of the lungs.

The State of Glottis. A consonant may be voiced or voice-less, depending upon whether the vocal cords remain wide apart (voice-less) or in a state of vibration (voiced).

The Position of the Soft Palate. While describing consonants we have to mention whether they are oral sounds (produced with soft palate raised, thus blocking the nasal passage of air) or nasal sounds (produced with the soft palate lowered).

The Articulators Involved. In the description of consonants, we have also to discuss the various articulators involved. The articulators are active (the lower lip and the tongue) and passive (the upper lip, the upper teeth, the roof of the mouth divided into the teeth-ridge, the hard palate, and the soft palate, and the back wall of the throat pharynx). In the production of a consonant the active articulator is moved towards the passive articulator. The chief points of articulation are bilabial, labiodental, dental, alveolar, post-alveolar, palato-alveolar, retroflex, palatal, velar, uvular, and glottal. In the case of some consonantal sounds, there can be a secondary place of articulation in addition to the primary. Thus, in the so-called dark /l/, in addition to the partial alveolar contact, there is an essential raising of the back of the tongue towards the velum (velarization); or, again some post-alveolar articulator of ‘r’ (r) as in red are accompanied by slight lip-rounding (labialization). We can classify consonants according to the place of articulation.

The Nature of Stricture. By the nature of stricture we mean the manner of articulation. This stricture of obstruction made by the or­gans may be total, intermittent, partial, or may merely constitute a nar­rowing sufficient to cause friction.

When the stricture is that of a complete closure, the active and pas­sive articulators make a firm contact with each other, and prevent the passage of air between them. For instance, in the production of /p/ as in pin and /b/ as in bin, the lips make a total closure.

The stricture may be such that air passes between the active and passive articulators intermittently. Such a stricture is called intermittent closure, and involves the vibration of the active articulator against the passive. The Scottish /r/ as in rat is an example. The intermittent closure may be of such a short duration that the active articulator strikes against the passive articulator once only. The English /r/ in the word very is an example; the tip of the tongue (active articulator) makes one tap against the teeth-ridge (passive articulator).

In the partial stricture, the air passes between the active and passive articulators continuously, but with some difficulty. The sounds thus pro­duced are clear /1/ and dark /1/ in late, and hill, the clear and the dark ‘1’ respectively.

And lastly, the stricture may be such that the air, while passing be­tween the active and passive articulators, produces audible friction. /f, v, q, ð, s, z, f, з, h/ in English are examples of this kind of stricture. Or the air may pass without friction. Examples are /w/ in wet, /j/ in yes and flap /r/ as in butter. A stricture which involves audible friction, can be called a stricture of close approximation, whereas one which involves no such friction can be called a stricture of open approximation.

If we are to describe some of the consonant sounds in terms of the points discussed in the preceding paragraphs, we shall do that in the following manner (we shall not make any reference to the air-stream mechanism since we have already mentioned that all English sounds are made with a pulmonic egressive air-stream):

1.   /p/ in the English word pack.

(i)      The vocal cords are held apart and the sound is voiceless:

(ii)     The soft palate is raised and the nasal passage is closed.

(iii)    The active articulator is the lower lip.

(iv)    The passive articulator is the upper lip.

(v)     There is a stricture of complete closure.

2.   /b/ in the English word back.

(i)      The vocal cords vibrate, and the sound produced is voiced.

(ii)     The soft palate is raised and the nasal passage is closed.

(iii)    The active articulator is the lower lip.

(iv)    The passive articulator is the upper lip.

(v)     There is a stricture of complete closure.

3.   /g/ in the English word god.

(i)      The vocal cords vibrate, and the sound produced is voiced.

(ii)     The soft palate is raised and the nasal passive is closed.

(iii)    The active articulator is the back of the tongue.

(iv)    The passive articulator is the soft palate.

(v)     There is a stricture of complete closure; the back of the tongue makes a complete closure with the soft palate.

4.   /t/ in the English words cat.

(i)      The vocal cords are wide apart, and the sound is voiceless.

(ii)     The soft palate is raised and the nasal passage is closed.

(iii)    The active articulator is the tip of the tongue.

(iv)    The passive articulator is the teeth ridge.

(v)     There is a stricture of complete closure. The tip of the tongue makes a firm contact with the teeth ridge.

5.   /m/ in the English word man.

(i)      The vocal cords vibrate and the sound is voiced.

(ii)     The soft palate is lowered and the air passes through the nose.

(iii)    The active articulator is the lower lip.

(iv)    The passive articulator is the upper lip.

(v)     There is a stricture of complete oral closure.

6.   /v/ in the English word van.

(i)      The vocal cords vibrate and the sound is voiced.

(ii)     The soft palate is raised and the nasal passage is closed.

(iii)    The active articulator is the lower lip.

(iv)    The passive articulators are the upper front teeth.

(v)     The stricture is one of close approximation. (The lower lip is brought very near the upper front teeth. The air passes between them with audible friction.)

7.   /j/ in the English word yet.

(i)      The vocal cords vibrate and the sound is voiced.

(ii)     The soft palate is raised.

(iii)    The active articulator is the front of the tongue.

(iv)    The passive articulator is the hard palate.

(v)     There is a stricture of open approximation. The front of the tongue is brought near the hard palate but the space between them is sufficient for the air to pass without any audible friction.

Hence the kind of stricture involved in the articulation of various sounds is as follows :

a)   plosive : complete closure,

b)   affricate : complete closure and slow release,

c)   nasal : complete oral closure,

d)   fricate : close approximation,

e)   lateral : complete closure in the centre of the vocal tract and the air passes along the side(s) of the tongue,

f)    vowel : open approximation,

g)   semi-vowel : open approximation,

h)   frictionless continuant : open approximation.

Classification of Consonants

Consonantal sounds are classified on the basis of (i) voicing, (ii) place of articulation, and (iii) manner of articulation.

(i) Voicing. On the basis of voicing, sound can be classified into voiced and voiceless sounds. The voiced sounds in English are /b, d, g, v. ð, z, dз, m, n, ŋ, l, r, w, j/.

All the vocoids and semi-vowels are voiced sounds, whereas among the consonants some are voiced and some voiceless. If the vocal cards vibrate when a sound is produced, it is said to be voiceless.

(ii) The Place of Articulation. Consonants are divided as given in the following table on the basis of the articulatory points at which the articulators actually touch, or are at their closest.

The Classification of English Consonants according to the place of Articulation.

Classification	Articulators	Examples
Bilabial	Upper lip and lower lip	/p b m w/
Dental	Teeth and tip of tongue	/q ð/
Labio-dentel	Lower lip and upper teeth	/f v/
Alveolar	alveolar (teeth) ridge and tip and blade of tongue	/t d s z r k b/
Post-alveolar	Hard palate and tip of tongue	/r/
Palato-aveloar	Hard palate—alveolar and tip, blade and front of tongue	/f/z/ò/dз/
Palatal	Hard palate and front of tongue	/j/
Velar	Soft palate and back of tongue	/k g ŋ/
Glottal	Glottis (vocal cords)	/h/

The Manner of Articulation           

According to the manner of articulation, which describes the type of obstruction caused by the narrowing or closure of the articulators, the conso­nants can be divided into stops. affricates, fricatives, nasals, rolls, laterals, and semi-vowels or frictionless continuants. We shall discuss these one by one.

(1) Stop. In the production of a stop, the oral and nasal passages arc closed simultaneously. The active and passive articulators come in contact with each other forming a stricture of complete closure and preventing the air from escaping through the mouth. The soft palate is raised and thus the nasal passage is also blocked. (This is also known as velic closure). The air behind the oral closure is compressed, and when the active articulator is removed from contact with passive one, the air escapes with an explosion. Stops are also known as mutes. explosives. plosives or occlusives. /p/ in pat and /b/ in hat are the examples of stops.

(2) Affricate. If the stop is not held for any appreciable time and released slowly, we get an affricate rather than a plosive, e.g. /tò/ in chair and /dз/ in jail.

(3) Nasal. In a nasal contoid, the breath stream is interrupted at some point in the oral cavity or at the lips, while being allowed to enter the nose and create resonance there. Thus a nasal is produced by a stricture of complete oral closure. The soft palate is lowered and the air passes through the nose. All nasal sounds are voiced. Examples /m, n, v/ in English.

(4) Trill (or Rolled Consonants). In the production of a trill, the active articulator taps several times against the passive articulator. The stricture in­volved can be called a stricture of intermittent closure. Scottish /r/, for example in red, in which the tip of the tongue strikes against the teeth ridge a number of times, is called a trilled consonant.

(5) Flap. For a flap the active articulator strikes the passive articulation once only. For example the /r/ in the English word very, in which the tip of the tongue strikes against teeth ridge only once.

(6) Lateral. Laterals are produced by a stricture of complete closure in the centre of the vocal tract, but the air passes out every one or both side of the tongue. For example, /I/ in late.

(7) Fricative. In the production of a fricative consonant the stricture is one of close approximation. The active articulator and the passive articulator are so close to each other that passage between them is very narrow and the air passes through it with audible friction. Examples are /f/ in face, /v/ in vain /q/ in think, /ð/ in them, /s/ in sail, /z/ in zero, /ò/ in ship, /з/ in measure, /h/ in hat.

(8) Frictionless Continuant. In the production of a frictionless continuant the stricture is that of open approximation. For example in the production of /r/ in red, read, real, ready, the active articulator (tip of the tongue) is brought just behind the passive articulator (alveolar ridge) so that there is plenty of space between the two articulators, and the air passes between them without friction; and hence the term “frictionless continuant.”

Gimson includes the English /r/ in words like red and read among the frictionless continuants, but the English (r) also occurs as a fricative as in try, cry, ray, pray, grow, very, sorry. Jones includes it in the list of fricatives and Gimson in the list of frictionless continuants.

(9) Semi-vowel. A semi-vowel is a vowel glide functioning as a consonant i.e., as the C element in syllable structure. In terms of articulation semi-vowels are like vowels, but they don’t behave like vowels. Semi-vowels are never stable; they can never be pronounced by themselves. They are sounds in transition. Examples are /j/ in yet and /w/ in wet. These are also called semiconsonants too.

(10) Fortis and Lenis. When we have voiceless/voiced pair, the two sounds are also distinguished by the degree of breath force and muscular effort in­volved in the articulations. e.g., is comparatively strong or fortis, and z is comparatively weaker lenis.

We summarize the classification of the consonants in English on the basis of the manner of articulation in the following table.

Name of the Class	Structure Involved	Examples
Stop	Complete closure	/p b t d k g/
Affricate frication	Closure, then slow separation Narrowing, resulting audible friction	/t ò dз/ /f v q ð s z ò з/
Nasal	Complete clsoure in mouth, air escapes through nose	/m n ŋ/
Rolled	Rapid intermittent closure	/r/
Lateral	Closure in the centre of  mouth, air escapes over the sides of tongue	/l/
Frictionless Continuant	Slight narrowing, not enough to cause friction	/r/
Semi-vowels/ Semi-consonants	Slight narrowing, not enough  to cause friction.	/w j/

Vowels

Vowels may be defined with an open approximation without any obstruc­tion, partial or complete, in the air passage. They are referred to as vocoids in phonetics. They can be described in terms of three variables:

(1)  height of tongue

(2)  part of the tongue which is raised or lowered

(3)  lip-rounding.

In order to describe the vowels, we usually draw three points in the hori­zontal-axes: front, central and back, referring to the part of the tongue which is the highest. So we have

i)    front vowels, during the production of which the front of the tongue is raised towards the hard palate. For example, /i, i:, e. æ/ in English as in sit, seat, set, and sat respectively.

ii)   back vowels, during the production of which the back of the tongue is raised towards the soft palate. For example /a:, , :, u, u:/ in English as in cart, cot, caught, book and tool respectively.

iii)  central vowels, during the production of which the central part of the tongue (the part between the front and the back) is raised. For example, /ә, ә:, Λ/ in English as in about, earth and but respectively.

To describe the vowel sound we mention whether it is open or close, half-close or half-open, front or back or central, long or short, whether the tongue is tense or lax while the vowel is being pronounced, and whether lips are spread, neutral, open rounded, or close rounded. All English vowels are voiced. So, for every vowel, we must state that it is voiced:

Diphthongs

From the point of view of their quality, vowel sounds are of two types : monophthong and diphthong. Monophthongs are pure vowels and diphthongs are gliding vowels. ‘A vowel that does not change in quality’ may be called a monophthong; and a vowel sound with a continually changing quality may be called a diphthong.

A pure vowel is one for which the organs of speech remain in a given position for an appreciable period of time. A diphthong is a vowel sound consisting of a deliberate, i.e. intentional glide, the organs of speech starting in the position of one vowel and immediately moving in the direction of another vowel. A diphthong, moreover, consists of a single syllabic––that is, the vowel-glide most be performed with a single impulse of the breath; if there is more than one impulse of breath, the ear perceives two separate syllables...

––Peter MacCarthy, English Pronunciation.

A diphthong, thus, always occupies one syllabic. If two adjacent vowels form the nuclei of two successive syllables, they are not a diphthong. For example the vowels in bay, boy, and buy are diphthongs, but the vowels in doing are two different vowels since they belong to two different syllables.

One end of the diphthong is generally more prominent than the other. Diphthongs are termed ‘decrescendo’ of FALLING if the first element is louder or more prominent than the second, and ‘crescendo’ or RISING if the second element is louder or more prominent than the first. All the English diphthongs are falling diphthongs, because in them the first clement is louder or more prominent than the second clement.

Diphthongs are represented in phonetic transcription by a sequence of two letters, the first showing the position of the organs of speech at the begin­ning of the glide, the second their position at the end. In the case of the ‘closing’ diphthongs the second letter indicates the point toward which glide (movement) is made.

Phonetic Transcription

Phonetic transcription is a device in which we use several symbols in such a way that one symbol always represents one sound. It is also known as phonetic notation, it is an ‘attempt on paper, a record of the sounds that speakers make.’ By looking at an English word in its written form one cannot be sure of its pronunciation, whereas by looking at it in phonetic transcription one can be. Most of our phonetic transcriptions are phonemic transcriptions, that is, each symbol represents a phoneme, a distinct sound unit in language. A pair of square brackets [ ] indicates a phonetic transcription: Phonemic transcriptions are enclosed within slant bars / /.

The Usefulness of the International Phonetic Alphabet (IPA)

The IPA gives us a uniform international medium of studying and transcribing the sounds of all the languages of the world. Many languages in the world have no orthographic (written) form at all. It has been made possible to study such languages with this alphabet. In other words, the IPA is ‘a precise and universal’ means (i.e. valid for all languages) of writing down the spoken forms of utterances as they are spoken without reference to their or­thographic representation, grammatical status, or meaning.

As regards English, the IPA helps us in establishing and maintaining international intelligibility and uniformity in the pronunciation of English. With the help of the IPA we can easily teach the pronunciation of English or of any other language. The IPA has contributed a lot in the teaching and description of language. The teachers and learners of English can improve, and standard­ize their pronunciation and can overcome the confusion created by the spell­ings with the help of the international phonetic alphabet.