SPEECH MECHANISM AND ORGANS OF SPEECH

                              SPEECH MECHANISM AND ORGANS OF SPEECH 

       Phonetics is the scientific study of speech sounds. It may be also described as the study of the production, transmission and reception of speech sounds. It furthers the classification of these sounds into consonant and vowel sounds. Phonetics is also concerned with the manner and place of articulation of these sounds. It also studies the stress and intonation used in the production of speech sounds by us. Every language has its own system of speech sounds. English speech sounds are produced when the air stream coming from the lungs assumes various shapes in the mouth during the process of breathing. In other words, we can say that speech is as essential a function of these organs as are the other function. Pulmonic Egressive Airstream Mechanism is used while producing sounds of English. The word Pulmonic refers to lungs and Egressive relates to throwing out. English is spoken when we throw the air out of our mouths in the process of breathing. All European languages are spoken by employing the Pulmonic Egressive Airstream Mechanism. All the Indian languages, except Sindhi, are also spoken in this way. The organs of the body which help in the production of speech sounds are called organs of speech. Most of the sounds are produced from different parts of our mouths. The tongue is also a major organ of speech. Here follows an account of the organs that help in the production of speech. Phonetics is the scientific study of what speech sounds exist in a language. It represents how the speech sounds are produced and perceived and what acoustic properties they have. Thus, it can be described in the class of natural sciences. 

    Phonetics essentially seeks to trace the processes physiologically involved in sound production. It also describes the ways the sounds are produced and the points at which they are articulated. Phonology is concerned with the regularities that govern the speech sounds in words of a language. It looks at and tries to establish a system of sound distinctions relevant to a particular language. It then seeks to determine how the elements of this abstract system behave in actual speech. Phonology actually delineates the functioning of sounds in particular contexts. The organs of speech had been adapted by human beings for speech production. The most important source of speech production is the air stream exhaled from the lungs. It is called the pulmonic Egressive Air Stream. It is also called Mechanism because it is the process of air stream release that works together to form sounds. The English language generally makes use of the Pulmonic Egressive Air Stream Mechanism for the production of speech sounds. However, it should be noted that some languages possess sounds not requiring lung or pulmonic air for their articulation.

1. The Respiratory System 

        The Respiratory System consists of The Lungs, The Muscles of the Chest, The Wind Pipe (Trachea) and the Bronchial Tubes. The lungs perform the function of breathing under the action of the chest muscles. The respiratory system is helpful in producing speech sounds in the sense that it provides the air stream which acts as the source of energy. No speech organ can produce speech sounds without the presence of the air which is provided by the lungs. The air released from the lungs initiates the speech mechanism. English speech sounds are produced with the help of Pulmonic Egressive Airstream Mechanism. The respiratory system plays a very significant role in the production of speech sounds in a particular language. The respiratory system, also called the gas exchange system, releases carbon dioxide and takes in oxygen. Carbon dioxide, a waste product, goes out of the body. Oxygen, which the body needs, comes in. The Lungs are the main organ to do this. In other words, we can say that the process of inhaling and exhaling oxidation of organic compounds is called the respiratory system. The first step in the process of inhaling and exhaling means bringing air rich in oxygen into the human body. The second step of the respiratory system is a gas exchange in the lungs where oxygen is diffused into the blood and the carbon dioxide diffuses out of the blood. The third process is cellular respiration, which produces the chemical energy that the cells in the body need, and carbon dioxide. Finally, the carbon dioxide from cellular energy is breathed out of the body from the lungs. he Organs of Speech are situated in the respiratory system, phonatory system and the articulatory system of the human body. According to one view, speech is the secondary function of these organs, their primary function being breathing, chewing, eating, smelling, tasting and so on.

 2. The Phonatory System 

The Phonatory System consists of vocal cords which are located in the larynx. These vocal cords are so flexible that they can close or open the air passage. When the need arises, the vocal cords close the air passage and prevent food from entering the windpipe. The lip-like structure of these vocal cords is horizontally placed in the larynx. These vocal cords are joined at the back. The opening between the vocal cords is called the glottis. The vocal cords can assume the following three position. 

Vocal Cords Drawn Wide Apart:  When the vocal cords are drawn apart, an opening, called glottis, appears between them. The air can pass through this opening without causing any vibration in the cords. There is the normal sounds produced when the vocal cords stand wide apart are called voiceless sounds because no hum is caused in the cords at the time of the production.

 The voiceless sounds produced in this way are as follows: /p/, /t/, /k/, /ts/, /f/, /Q/, /s/, /h/. When the vocal cords are held apart these nine sounds are produced. T. There is a wide gap visible in the vocal cords . 

Vocal Cords Held Loosely Together: When the vocal cords are held loosely together, the air passing through the glottis causes vibration in them. The speech sounds produced when the vocal cords are in this position are called voiced sounds. All the twenty vowel sounds are also voiced sounds. 

Vocal Cords Held Tightly Together: When the vocal cords are held tightly together, the glottis is closed along with the whole life. Vocal cords adopt thus position when we eat or drink something. The closure of the vocal, cords prevents the food stuff from going into the windpipe. The glottal stop is responsible for the mild cough in the throat. The following diagram shows the position of vocal cords when they are held tightly together.

 3. The Articulator System

   The Articulator System consists of those speech organs which are directly involved in the production speech sounds. All these organs of speech are chiefly located at various places in the mouth between the lips and the pharynx. The articulator system thus consists of the lips, the teeth, the teeth ridge, the hard palate, the soft palate, and the uvula. All these organs are situated on the roof of the mouth but the tongue which is the most important organ of speech is situated in the lower part of the mouth. We can understand the working of the articulatory system with the help of the following diagram. The space between the vocal cords is called the glottis. Above the vocal cords, in the vocal tract itself, are several parts that move in various ways to change the size and shape of the open part of the vocal tract and produce all the sounds of English, or any other language. These are called the articulators.

 (a) Pharynx: The Pharynx extends from the tip of the larynx to the root of the tongue. The pharynx and the root of the tongue lie just opposite each other. The muscles of the pharynx have the capacity to contract and expand in this way. They modify the shape and size of the pharyngeal cavity. The position of the pharynx is affected by the movement of the back of the tongue. Each of such modifications affects the quality of the sound performed by an individual.

 (b) The Lips: the lips are located at the front of the oral tract. They play an important role in the production of certain speech sounds. The consonant sounds /p/, /b/, are produced when we first close the lips and then release the air abruptly by opening the mouth. When the consonant /m/ is produced, we bring both the lips together and then allows the air to pass through the nose. The lips also assume various shapes during the production of the vowel sounds. 

(c) The teeth: The Teeth are responsible for the production of the RP sounds. The sounds /Q/ and /th/ are produced by the tongue at the back of the upper teeth. The sounds /f/ and /v/ are produced when the lower lips come in contact with the upper teeth.

 (d) The Teeth Ridge: The Teeth Ridge is also called the alveolar ridge. It is the convex part of the roof of the mouth lying just behind the upper teeth. This hard and raised structure can be felt with the tip of the tongue. The teeth ridge is the articulatory point of certain consonant sounds. The sounds like /h/ and /d/ of the RP are produced when the tip of the tongue comes in the contact with the teeth ridge and then the closure is suddenly released. The /s/ and /z/ sounds of the RP system are produced by narrowing the passage of the air at the teeth ridge and forcing the air out from this narrow passage with some friction. 

(e) The Hard Palate: the bone-like hard and concave surface located immediately beyond the alveolar ridge in the roof of the mouth is called the hard palate. The initial sound of the word yes /y/ is articulated here. 

(f) Soft Palate: The Soft Palate is located in the back part of the roof of the mouth just behind the hard palate. It is also called vellum. It is rightly called soft palate because it is soft, flexible and movable. G The velum is responsible for articulating certain RP sounds. The sounds /k/ and /g/ are produced at the velum. In the production of these sounds, the velum acts simultaneously in two ways. First, the back part of the tongue moves towards it and thus it causes complete closure. Secondly, it touches the back wall of the pharynx by raising itself. In this way, it closes the nasal passage which is called valid closure. In this case, the air passes through the mouth and the oral. 

(g) The Uvula: The Uvula is a pendent-like structure of flesh hanging at the end of the soft palate. It is situated at the end of the oral cavity in the upper portion. The back part of the tongue touches it to produce certain sounds of other languages. But the RP system has no uvular sound.

 (h) The Tongue: The Tongue is the most important and the most flexible of all the articulatory organs. It can easily move from one place to the other place and thus assumes positions which give rise to the articulation of different consonant and vowel sounds. The tongue may be divided into six parts named Tip, Blade, Front, Back, Root and Rims. The part of the tongue that lies behind the lower teeth is called the tip of the tongue. The part that lies opposite the teeth ridge is called a blade. The front of the tongue lies opposite to the hard palate. The part that lies opposite to the soft palate is called the back of the tongue. Any part of the tongue can be raised to any height to make contact with any part of the roof of the tongue. Vowel sounds are produced when the tongue regulates the air coming from the glottis in a stream which is called the case of open approximation.

     Consonant sounds are produced when the tongue causes a stricture of complete closure or narrow approximation. Active articulators are Lips, Tongue, Lower Teeth and certain position of the soft palate. Passive Articulators Upper Teeth, teeth Ridge, Hard Palate and certain parts of the soft palate. Classification of Consonant and vowel sounds. In English, there are 26 letters which produce 44 sounds containing 20 vowel sounds and 24 consonant sounds.

     In the production of 12 monophthongs and 8 diphthongs, the tongue’s position remains unchanged whereas there should be friction and obstruction in the production of consonant sounds. The description and classification of consonant sounds depend on the place and manner of articulation. According to the place of articulation, consonant sounds can be classified as bilabial, labio-dental, dental, alveolar, post-alveolar, retroflex, palato-alveolar, palatal, velar, uvular and glottal. According to the manner of articulation, they can be divided as plosive, affricates, nasal, rolls, taps, flaps, lateral, fricatives, frictionless, continuants and semi-vowels. The place of articulation of consonant sounds are determined by the passive articulator involved in the production of the sounds. 

    The articulatory system can not be involved in the production of vowel sounds. We can also make a distinction between one vowel and another vowel by mentioning the height of the tongue, raised in various position. Thus, the organs of speech play a very significant role in the development of a language. The chief aim of this research paper is to study how speech sounds are pronounced, how they travel from the speaker to the listener, and how these sounds function in a language. The sounds of English are produced by inhaling and exhaling air into the lungs. Producing different speech sounds of a language depend on the movement and classification of speech organs. It is essential to know the description and classification of each organ to produce particular sounds of a language. The above classification and description of speech sound of English help us to guide the students to learn the 20 vowel sounds and 24 consonant sounds in a right way. 

    The air mechanism can be modified at certain points which classify the distinct speech sounds of English. The study of the phonetics is based on the organs of speech. A clear understanding of The Respiratory System, The Phonatory System and The Articulatory System can change the style of individual’s pronunciation. The lungs, in the position of inhaling and exhaling can create the sound which is turned into vibration by the vocal cords in our larynx. These speech sounds can be studied at three stages: the production, the transmission and the reception. Vowel sounds are pronounced with the help of the mouth and the pharynx without any obstruction whereas all other consonant sounds are pronounced with friction and obstruction.