Phonetics and Organs of Speech

Phonetics and Organs of Speech

  Linguistics is a study of language. Phonetics is a branch of Linguistics, which deals with production, transmission and reception of speech sounds. Thus, the study of speech sound is known as Phonetics. Phonetics is concerned with how speech sounds are produced in the vocal tract and the physical properties of it. It is made of three different stages:

 (a) Articulatory Phonetics (which deals with production of speech),

 (b) Acoustic Phonetics (which deals with the transmission of speech throughout air). This is concerned with studying the properties of sound as a consequence of vibrations in air pressure.

 (c) Auditory Phonetics (which deals with the reception of speech sounds by the internal diaphragm fitted in the air-cavity).

 The outer ear collects the sound, the middle ear amplifies them and passes them to the inner ear. the sounds are smeared across each other.

 

 

   Organs of Speech:

         Actually speech is 'modulated breathing'. Air streams make speech sounds possible. The air (mainly lung-air) that flows out of the mouth gets modulated into speech sounds with the help of the certain organs of the body. These organs are referred to as organs of speech. The organs of speech can be divided into three heads:

  (a) The Respiratory System: This system involves the lungs, the chest muscles and the trachea and the wind pipe.

  (b) The Phonatory System: This system involves the larynx (the upper part of the trachea).

  (c) The Articulatory System: This system comprises the pharynx (the cavity forming the upper part of the gullet), the teeth, tongue, the roof of the mouth, the lips and the nose.

 

 

 

 

       The Respiratory System:

     This system consists of the lungs, the muscles of the chest and trachea or wind pipe. The lungs are spongy bodies. They are made up of alveoli (small spongy sacs). Small tubes that supply air to these alveoli are bronchioles. The large unified bronchioles are known as bronchi. The bronchi connect the windpipe or trachea. And through windpipe the air passes through the throat into the lungs. Respiration involves two different as well as opposite processes: inspiration and expiration.

 

    The Phonatory System:

 The Larynx:- In the upper part of the trachea is a muscular structure which is known as larynx. It is commonly called the 'Adam's Apple'. A pair of lip like structures is there in the larynx. These are the 'vocal cords'. These are placed horizontally from front to back, and joined at the front but separated at the back.

    These vocal cords can have three possible positions.

 

  1. Vocal cords drawn wide apart: In this condition, there is a wide opening between the cords. This gap is known as 'glottis'. Air can pass freely (through glottis) without the disturbance or vibration of the vocal cords. Voiceless sounds are produced in this condition. For Example, the initial sounds of the English words: pen, chair, tin, hat etc.

 

 

 

  2. Vocal cords held loosely together: In this structure of the vocal cords vibration is a must. Generally voiced sounds are produced under such condition. For example, the initial sounds in English words: nun, must, got, bat etc.

 

3. Vocal cords held together (tightly): In this structure, the glottis remains closed. Air cannot pass through the glottis. Vocal cords stand in this condition at the time of eating and drinking.

 

 

 

 Articulatory System

  

  The Lips: The lips play a crucial role in the production of speech sounds. The initial sounds in the English words pen and pin, ball, bag for example, are made with the help of lips. The lips play an important part even in producing some vowel sounds (as the initial sound of wet) in English

   The Teeth: Some English consonants are made with the help of teeth.

 For example, the initial sounds of four, father, though, than etc. 

   The Tongue: It is an important organ of speech. Tongue is divided into three distinct parts - tip, blade and front. It is flexible by nature. The tongue is moved accordingly to produce English speech sounds. 

The hard and soft plate: The hard plate is the bony, concave surface lying immediately behind teeth ridge

   The soft portion of the roof after the hard plate is known as soft plate. It has another name velum. It is an important organ of speech for a large number of sounds such as the initial sounds in the English words: go, gain, knight etc.

   There may be three conditions regarding the placement of the soft plate:

  (a) Soft plate in raised conditions: It blocks the nasal passage. (velic closure), Only 'oral sounds' (like /l/, /p/, /t/ etc.) are produced in this condition.

   (b) Soft plate is lowered: There is no velic closure. It is velic opening. The oral passage is blocked by closing the lip. Air can escape only through the nose. Nasal sounds (like /m/n/y) are produced in this condition.  

   (c) Soft plate is lowered but there is no blockage at the oral or nasal passage: In this condition there is neither velic nor oral closure. Nasalised sounds are produced in this condition. 

(1) The last sound in the French word 'bon' (good) is an example of nasalised sound. (2) The vowel sound in the Bangla word, 'বাঁশ' Bansh (bamboo) is a nasalised sound. 

 

 

  Production of nasalised sounds

 

 

 

 

 

 

 

 

                                                                                                                                                                                              

 

 

Active and Passive Articulators: The articulators (organs of speech) which move from their normal position in order to produce speech sounds are known as active articulators. For example: in the production of /t/ the tip and the blade of the tongue move from their original positions to articulate against the teeth. Here the active articulator is the tip and blade of the tongue. The organs that do not move from their position in the process of productions of speech sounds are known as passive articulators. Teeth ridge acts as the passive articulator (in the above example).

  

   

 The Air-Stream Mechanisms: Lung-air is used in the process of articulation of most speech sounds of most language. Ann air-stream is produced in air-stream mechanism. It has close approximity with the behaviour of a flitgun. There are three kinds of air-stream mechanisms involved in the articulation of speech sounds (in English):

 

  (a) Pulmonic air-stream mechanism: The walls of the lungs act as the initiator. It is the most important air-stream mechanism for the production of speech sounds.

  (b) Glottalic air-stream mechanism: The closed glottis acts as the initiator. The air in the phraynx is used in the process.

  (c) Velaric air-stream mechanism: For this mechanism the back of the tongue is the initiator and the air in the mouth is used in the process.

 

 

 

 

 

 

 

 

  When the air-stream mechanism is used to push air out, it is known as 'egressive' and when it is used to take air in, it is called 'ingressive'. We use 'pulmonic egressive air-stream mechanism' for the production of the sounds in English and 'pulmonic ingressive air-stream mechanism' for yawning and snoring, but obviously not for speaking.