The Production of Sounds ~ ENGLISH PHONOLOGY

The production of sounds is possible because of the cooperation of four aspects. Those four aspects are (1) the air-stream mechanisms, (2) the speech organs or articulators, (3) the glottis, and (4) the velum.

1. The Air-Stream Mechanisms

An air-stream is the basis of the whole of the human speech sounds, An air-stream is produced by an air-stream mechanism. There are three main types of air-stream mechanisms in human sound-producing system, namely, (1) pulmonic air-stream mechanism, (2) glottalic air-stream mechanism, and (3) velaric air-stream mechanism. Among these three air-stream mechanisms, only the pulmonic air-stream mechanism that plays an important role in the production of speech sounds; the other two also play a role in the production of sounds, but most of them are non-linguistic. Each of these air-stream mechanisms has its own initiator which can set an air-stream in motion.

The pulmonic air-stream mechanism consists of the lungs and the respiratory muscles. The respiratory muscles move the lungs, so that air is either drawn into the lungs or pushed out of them. The air-stream drawn into the lungs is called the ingressive air-stream, and the air-stream pushed out of the lungs is called egressive air-stream. The air-stream which plays a very important role in the production of linguistic sounds is the egressive air-stream.

2. The Articulators

The articulators also play a very important role in the production of speech sounds. These articulators lie in the head, particularly in the mouth. These articulators are commonly divided into (1) active articulators and (2) passive articulators.

The active articulators are the articulators that can move toward the passive articulators and include the lower lip, the lower teeth, the tip of the tongue, the blade of the tongue, the body or front of the tongue, and the back of the tongue and the velum, All these active articulators, except the velum, lie in the lower pan of the mouth. The passive articulators are the articulators that cannot move and lie in the upper part of the mouth. They include the upper lip, the upper teeth, the teeth-ridge, the hard palate, and the front pan of the soft palate. These articulators, both active and passive articulators, can block the air-stream coming from the lungs completely or partly at some point in the mouth, depending upon what sounds are produced.

3. The Glottis

The pulmonic air-stream on its way into or out from the lungs has to pass the wind-pipe or trachea lying at the top of the larynx. The larynx also plays an important role in the production of speech sounds. The most important part of the larynx is the vocal cords (also commonly called the vocal folds or vocal bands). The space between the vocal cords is called the glottis. The vocal cords can produce a number of different states of the glottis. There are three primary states of the glottis, namely, (a) open glottis, (b) glottis in vibration, and (c) closed glottis. When the vocal cords are pulled apart, the air-stream passes directly through the glottis. Sounds produced with the vocal cords in this state is said to be voiceless sounds, namely, sounds produced without the vibration of the vocal cords. When the vocal cords are brought close together, but not tightly closed, the air-stream passing between .them causes them to vibrate, producing the so-called voiced sounds. The vocal cords can also be brought together tightly, and this is the state for producing glottal stop.

4. The Velum

The velum is the end pan of the soft palate which has two positions, namely, raised position and lowered position. If it is raised, it hampers the air-stream to pass through the nose, so that it passes through the mouth producing the so-called oral sounds, namely, sounds produced in the mouth. The oral sounds in English are as follows: p, b, t, d, k, g, d, j, f, v, 9, ö, s, z, S, i, h, l, r, w, and y, If it is lowered, it hampers the air-stream to pass through the mouth, so that it passes through the nose producing nasal sounds, namely, m, n, 0 and nasalized vowels, such as T, T, ä, ö, etc.