SPEECH ORGANS

Organs of speech

In our body we have many body parts- internal and external, which are used to perform different functions. Out of all the body parts, the organs which are used to produce sounds (phones) are called organs of speech. When we speak, these organs help us to make different sounds.

All the organs of speech are divided into three groups

A.    The articulatory system

B.    The phonatory system

C.    The pulmonary system: it brings air (oxygen) to the body

 These organs start from oral tract and lasts to chamber of lungs. All the organs of speech are given below-

TYPES OF SYSTEMS AND ORGANS OF SPEECH

 

 

Place and Function of Speech of Organs

 A.    ARTICULATORY SYSTEM

The articulation process is the most obvious and important too. It is the third element of speech production. Articulation is the term used for all actions of the organs of the vocal tract that effect modifications of the signal generated by the voice source. It takes place in the mouth and we can differentiate most of the speech sounds with the help of this mechanism. In the mouth, oral cavity acts as a resonator while tongue, lips, mouth roof are called articulators.

Articulators are of two types- active and passive. Among the articulators we have

1.               Upper lip and lower lip

2.               upper and lower teeth,

3.               tongue (tip, blade, front, back) and

4.               roof of the mouth (alveolar ridge, palate and velum).

In the articulatory system we study about various articulatory organs-

1.     Nasal cavity:

It is the cavity which starts from nostril (opening of nose) and extends till it joins the pharynx. It is internal nose area.  Air passes through nose and helps in production of sound like /m/, /n/ etc.

2.     Lips:

lips are placed just at the opening of mouth. They serve for creating different sounds, mainly the

labial, bilabial for example /p/, /b/, /m/  etc. The sounds produced with the help of lips and teeth are called labio-dental for example /f/, /v/ etc.

3.     Oral cavity/buccal cavity:

It includes the area between lips and mouth cavity. It allows various movements of speech organs to move freely. It plays a significant role in determining the phonetic qualities of speech sounds. The shape and volume of the oral cavity depends on the shaping and positioning of the tongue, moving of the lips, jaw and soft palate.

                           i.          Teeth:

Teeth are the small whitish structures found in jaws in front of mouth in the oral cavity just behind the lips. They guard the oral cavity. Teeth are helpful in production of many sounds. /t/, /n/, / ð/, / θ/ etc

                         ii.          Alveolar ridge:

Alveolar ridge is basically hard ridge behind the upper front teeth. It is between the roof of the mouth and the upper teeth. It is also known as the front part of the roof of the buccal cavity (alveolar). Teeth are fixed in it. It is helpful in the projection of many sounds like /t/, /n/, /d/ etc. when front part of the tongue touches the front part of the alveolar ridge.

                       iii.          Hard palate:

It is the center part of the roof of the buccal cavity. Hard palate is a thin horizontal bony plate of the skull, located in the roof of the mouth. It is often called the roof of the mouth. It is curved in shape. When tongue touches the hard palate then the sounds like /r/ is produced.

                       iv.          Velum (soft palate)

It is the end part of the alveolar ridge towards the pharynx. It is in a position that allows air to pass through the nose and through the mouth. During speech, it is raised so that air cannot escape through the nose. Its mains function is to separate the nasal cavity from oral cavity in order to produce the oral speech sounds. It is helpful in the production of sounds like /ʈʃ/, /dʒ/ etc.

                         v.          Uvula:

Uvula is a muscular part hanging in the buccal cavity. It functions is to create a number of guttural and other sounds. it closes to prevent air escaping through the nose when making some sounds.

                       vi.          Tongue:

The tongue is a very important articulator and it can be moved into many different places and different shapes. Its movement in oral cavity plays important part in production of almost every speech sound. usually, it is divided into different parts like

a)     apex (tip) of tongue

b)    blade (front) of tongue

c)     dorsum (back) of tongue

4.     Pharynx:

Pharynx is a tube in which both the nasal cavity and oral cavity open. Its distal end divided into larynx and esophagus (food pipe).

5.     epiglottis:

It is a small projection at the top of the larynx. It covers the larynx when food comes downward from pharynx. It allows air stream to enter into pharynx.

B.    PHONATORY SYSTEM

Phonatory system includes ‘Phonation mechanism’ which takes place when voice is produced in the speaking process. During phonation air stream moves up and enters the trachea or wind pipe of larynx. The main parts of the Phonatory system are- larynx, vocal cords and glottis.

1.     larynx:

It is also called voice box. It is a structure of cartilages and muscles situated just above the trachea. It is helpful in the production of several types of sound effects like voice quality, pitch, whisper etc. It contains vocal cords and glottis.

 

2.     vocal cords:

There are two horizontal bands of ligament and muscle. Their vibration helps in the articulation of vowels and of many consonants. These are also called vocal folds.

3.     Glottis:

The space between the vocal folds is called the glottis. As the vocal folds vibrate, the resulting vibration produces a ‘buzzing’ quality to the speech called voice. The sound produced only by the glottis is called Glottal sound like /h/.

 

SN	Vocal codes	glottis	Speech sounds	examples
1	apart	open	Voiceless sounds	/p/, t/t, /k/, /f/, /ʈʃ/ etc
2	vibration	Open & closed simultaneously	Voiced sounds	/b/, /d/, /g/, /m/, /l/ etc
3	Closed tightly	closed		Cough, hiccups etc
4	Narrow	narrow		whispering

 

C.    PULMONARY SYSTEM

Pulmonic system includes the movement of lung air by the respiratory muscles. Most sounds are produced with a pulmonic airstream mechanism. The main organs of Pulmonic systems are -

4.     Trachea:

 It I also called wind pipe. It is a tube which has cartilages. It opens one side in Larynx and at the other end it splits into two bronchi that connect to the lungs.

5.     Bronchi:

Two tube like structures which join both the lungs to the trachea are called bronchi. It helps in the passage of stream flow of air from lung to trachea.

6.     lungs:

These are two in numbers. These are elastic structure which are placed in thorasic cavity and protected with rib case. These supply the source of energy for speech i.e. flow of stream of air when we breathe out (exhale).