Phonetics.

Phonetics is the science of speech sound. It is important to know the

mechanism of human speech sound production because much of the

communication done by human beings is carried on through speech. It is natural

for human beings to learn a language first by listening, which is then imitated by

speaking; this leads us to the development of more formal skills of reading and

writing. Thus we see Phonetics helps us to improve our Listening and Speaking

skills by helping us to be accurate in the production of the sound and be sensitive

in receiving of the sound. This should eventually give us a better grounding in the

language.

Language is a medium working in the spoken and written form. Almost in

all the cultures the more formal format is the written form that takes shape after the

language has been developed in the spoken form. Thus we see the written form of

language comes from the spoken format. Alphabets used in the written format are

signs of the sounds delivered while speaking. Hence written language is a

transcription of the spoken language. For example; the word hid is a word of three

sounds phonetically described as /hid/. We also have word like hide where ‘i’

could carry two sounds as it is here /ai/. The mechanism of producing sounds like

these is studied by Phonetics.

A renowned scholar of Phonetics Dr. T. Balasubramanian describes

Phonetics as,

“Linguistic is the systematic study of the language. Phonetics is a branch

of linguistics dealing with the medium of speech. It deals with the production,

transmission and reception of sounds of human speech.”

Air Stream Mechanism

Speech sounds are produced by the help of the breath and use of the organs

of speech like lips, teeth, tongue, nose and the roof of the mouth. Most of the

speech sounds are produced by throwing out air from the lungs into the outer

atmosphere or expiration.

There are three main air –stream mechanisms. These are called

1.) pulmonic, ( functions of the lungs)

2.) glottalic and

3.) velaric.

Large number of speech sounds is produced from pulmonic air stream

mechanism that operates on lungs and the muscles in the respiratory system. The

walls of the lungs act as the initiator.

The glottalic air stream mechanism produces sound by closing or opening of

the glottis in the wind pipe. This is also called pharyngeal air stream mechanism.

The velaric air stream mechanism produces sound by the back of the tongue.

This is also called the oral air stream mechanism.

Vocal cords are the lip-like structures in the windpipe in our throat. They

vibrate by the breathing out of air through mouth and this produces sound. The

opening between the cords is called glottis. When the sounds are produced by the

wide-open glottis they are called voiceless sounds like the first sounds in the words

peel, ten, keen. When the vocal cords are relaxed, the air pressure form the lung

makes them vibrate quickly and voiced sounds are produced. Like in words girl,

bead, deed. The rate at which the vocal cords vibrate is called frequency and this

determines the pitch of the voice. A speech becomes effective with the proper use

of pitch, tone and sound of the word called pronunciation.

The Articulatory System

This area comprises of

(1) the teeth ridge, (the convex part of the roof of the mouth)

(2) the hard palate,(bony concave surface)

(3) the soft palate, (velum) and

(4) the uvula.(fleshy structure hanging at the end of the roof)

When air escapes through nose and the mouth then nasalized sounds are

produced. Like in the words, sum, son, song.

The tongue

The tongue is a very important organ of speech. It can take different positions

during the production of the sound. We can divide the tongue into the tip, the

blade, the front, the back and the root.

The lips

The lips also have an important role in articulating the sound. For example the

first sounds in the English language like pill, mill, bill are produced with the lips

closed.

Speech sounds are broadly divided into two categories, vowel sounds and

consonant sounds. Like in the word “shoe” two sounds follow each other ‘sh’ and

‘oe’. ‘Sh’ is produced by friction and ‘oe’ without friction. During friction air does

not pass freely from the mouth. When we produce sound with the help of friction

such sounds are consonants and when the sound is produced without friction we

have vowel sounds.

Vowel Sounds

There are twenty distinctive vowel sounds in English. For example the words

‘head’ and ‘had’ have different vowel sounds. So they belong to different

phonemes. A Phoneme is defined as a minimal distinctive sound unit of a

language. In English language the 20 distinctive vowel sounds are further sub-

divided. 12 are pure vowel sounds, monophthongs and 8 vowel sounds glide or

have two sounds combined known as dipthongs.

The following list shows the different vowel sounds

Consonant Sounds

There are twenty four distinctive consonant sounds in English produced by friction

in the mouth cavity. As shown in the following table.