Gimson Chapter 4: Description and Classification of Speech Sounds

Gimson Chapter 2. The Production of Speech. The Physiological Aspect.

The Speech Chain: Any manifestation of language by means of speech is the result of a highly complicated series of events. In the first place, the formulation of the concept will take place at a linguistic level, the first stage may be said to be psychological. The nervous system transmits this message to the so-called organs of speech. The second important stage is said to be articulatory or physiological. The movement of our organs of speech will create disturbances in the air, these varying air pressures may be investigated and they constitute the third stage, the physical or acoustic.

These stages will be reversed at the listening end: the reception of the sound waves by the hearing apparatus (physiological) and the transmission of the information along the nervous system to the brain, where the linguistic interpretation of the message takes place (psychological).

The Speech Mechanism: The human being differs from other animals in that he has been able to organize the range of sounds which we can emit into a highly efficient system of communication. When we speak we make use of organs whose primary physiological function is unconnected with vocal communication, namely those situated in the respiratory tract. The most usual source of energy for our vocal activity is provided by n air-stream expelled from the lungs. All the essential sounds of English need lung air for their production: our utterances are, imitations imposed by the capacity of our lungs and by the muscles which control their action. The air-stream provided by the lungs undergoes important modifications in the upper stages of the respiratory tract before acquires the quality of a speech sound: first of all, in the trachea windpipe, it passes through the larynx, containing the so-called vocal folds. The larynx is a casing, formed of cartilage and muscle, situated in the upper part of the trachea. The opening between the folds is known as the glottis. Biologically, the vocal folds act as a valve which is able to prevent the entry into the trachea and lungs of any foreign body or which may have the effect ?????In using the vocal folds for speech, the human being has adapted and elaborated this open-or-shut function in the following ways:

a) The glottis may be held tightly closed, with the lung air pent up below it.

b) The glottis may be held open in such a way that, when the air-stream is expelled through with sufficient energy, there is audible glottal friction.

c) The action of the vocal folds consists in their role as a vibrator set in motion by lung air: the production of voice, or phonation. In order to achieve the effect of voice, the vocal folds are brought sufficiently close together that they vibrate when subjected to air pressure from the lungs. We are able, within limits, to vary the speed of vibration of our vocal folds; we can alter the amplitude of the vibration.

d) A very quiet whisper may result merely from holding the glottis in the voiceless position [/h/]. Such a whisper may in fact be uttered with an almost total closure of the glottis and an escape of air in the region of the arytenoids.

The air-stream, having passed through the larynx, is now subject to further modification according to the shape assumed by the upper cavities of the pharynx and mouth and according to whether the nasal cavity is brought into use or not. These cavities function as the principal resonators of the note produced in the larynx. The pharyngeal cavity extends from the top of the larynx and esophagus, past the epiglottis and the root of the tongue, to the region in the rear soft palate. The escape of air from the pharynx may be effected in one of three ways:

a) The soft palate may be lowered, as in normal breathing, in which case the air may escape through the nose and the mouth.

b) The soft palate may be lowered so that a nasal outlet is afforded to the air stream, but a complete obstruction is made at some point in the mouth, with the result that, although air enters all or part of the mouth cavity, no oral escape is possible.

c) The soft palate may be held in its raised position. All normal English sounds, with the exception of the nasal consonants mentioned, have this oral escape.

Although all the cavities play an essential part in the production of speech sounds, most attention has been paid to the behaviour of the cavity formed by the mouth. The only boundaries are, in the front, the teeth, in the upper part, the hard palate; and in the rear, the pharyngeal wall. The remaining organs are movable: the lips, the various parts of the tongue, and the soft palate with its pendent uvula. The lower jaw, too, is capable of very considerable movement. The roof of the mouth is divided intro 3 parts:

1. Moving backwards from the upper teeth: alveolar.2. The bony arch which forms the hard palate and which varies in size and arching from one individual to another.3. The soft palate or velum which is capable of being raised or lowered.

The lips constitute the final orifice of the mouth cavity. If they are held apart, the positions they assume may be:

1. Held sufficiently close together over all their length that friction occurs between them.

2. Spread lip position e.g see

3. Neutral position e.g get

4. Open position e.g card

5. Close rounded position e.g do

6. Open rounded position e.g got

The tongue is the most flexible organ, and is divided into three sections: the front, the back and the centre. The tapering section facing the teeth ridge is called the blade and its extremity the tip. The tip and blade region is known as the apex. The edges of the tongue are known as the rims.Gimson Chapter 4. Description and Classification of Speech Sounds.Phonetic description: A speech sound has at least three stages available for investigation: the production, transmission and reception stages. A complete description of a sound should, therefore, include information concerning all three stages.

Vowel and consonant: The articulation of vowels which would prevent the escape of the air stream through the mouth or give rise to audible friction; all other sounds are consonants.

From the practical phonetic standpoint, we distinguish two types of speech sound:

1. The consonantal type: the one which is most easily described in terms of articulation. Such sounds may be produced with or without vocal fold vibration and very often have a noise component in the acoustic sense. 2. The vowel type: depending largely on very slight variations of tongue position that is not accompanied by any closure or narrowing in the speech tract. Such sounds are generally voiced, having no nose component but rather a characteristic patterning of formants.Questions about the consonantal type: terico

Egressive pulmonic consonantal sounds: Most speech sounds, and all normal English sounds, are made with egressive lung air. At any point of articulation, a consonantal articulation may be voiceless or voiced.

Place of articulation: The chief points of articulation are the following:

Bilabial: the two lips are the primary articulators. [p,b,m]

Labio-dental: the lower lip articulates with the upper teeth. [f,v]

Dental: the tongue tip and rims articulate with the upper teeth [0,d]

Alveolar: the blade, or tip and blade, of the tongue articulate with the alveolar ridge. [t,d,l,n,s,z]

Post-alveolar: the tip (and rims) of the tongue articulate with the rear part of the alveolar ridge.[ ]

Retroflex: the tip of the tongue is curled back to articulate with the part of the hard palate immediately behind the alveolar ridge.

Palato-alveolar: the blade, or the tip and the blade, of the tongue articulate with the alveolar ridge and there is at the same time a raising of the front of the tongue towards the hard palate.

Palatal: the front of the tongue articulates with the hard palate.

Velar: the back of the tongue articulates with the soft palate.

Uvular: the back of the tongue articulates with the uvula.

Glottal: an obstruction, or a narrowing causing friction but not vibration, between the vocal cords.Manner of articulation: Complete closure: plosive, affricate, nasal. Intermittent closure: roll, flap

Partial closure: lateral

Narrowing: fricative

Semi-vowels and frictionless continuants: Semi vowels [w,j] are usually included in the consonantal category on functional grounds, but from the point of view of phonetic description they are more properly treated as vowel glides. Frictionless continuants or approximants [ ] have neither the closure nor the noise component characteristic of consonantal segments; they are variants of consonantal types.Fortis and Lenis: a voiceless/voiced pair are distinguished not only by the presence or absence of voice but also by the degree of breath and muscular effort involved in the articulation. The voiced consonants which are articulated with relatively weak energy are lenis; and those which are voiceless and strong are fortis.Classification or egressive pulmonic consonantal articulations: the essential factors to be included in any classificatory chart refer to: the place of articulation, the manner of articulation, the presence or absence of voice and the position of the soft palate.Egressive glottalized consonants [h, ]: speech sounds may be articulated without the passage of lung air into the upper speech tract. In the production of these sounds, known as glottalized or ejective, the glottis is closed so that lung air is contained beneath it.The vowel type: this category is made with a voiced egressive air-stream. Vowels description must include:1st. The position of the soft palate

2nd. The kind of aperture formed by the lips

3rd. The part of the tongue which is raised and the degree of raisingThe cardinal vowel scale in the cardinal vowel system, created by Daniel Jones, the basis of it is physiological. Three auditory equi-distant points were established from the lowest to the highest position. A scale of eight primary cardinal vowels was set up.

The front series (I,e,3,a) and (a) of the back series are pronounced with spread or open lips, whereas the remaining three members of the back series have varying degrees of lip rounding. A secondary series can be obtained by reversing the lip position. In addition, a pair of cardinal vowels, unrounded and rounded has been established. It is possible to give a visual representation of the vowel relationships on a chart which is based on the cardinal vowel tongue positions. The internal triangle is made by dividing the top line into three equal sections and drawing lines parallel to the two sounds, so that they meet near the base of the figure.

Nasality: a vowel description must indicate whether the vowel is purely oral or whether it is nasalized. The eighteen cardinal vowels mentioned may all be transformed into their nasalized counterparts if the soft palate is lowered.Relatively pure vowels and gliding vowels The classification of vowel type articulations