The organs, which take part in the production of speech sounds, are called speech organs. When we speak, air comes out through the lungs and it is interfered at various places for the production of sounds. Sounds cannot occur without air. The following diagram shows the main organs of speech.
1. Lips 7. Epiglottis
2. Teeth 8. Pharynx
3. Alveolar ridge 9. Soft palate
4. Tongue 10. Uvula
5. Larynx 11. Hard palate
6. Vocal cords
Descriptions and functions of some important organs of speech
Þ The vocal cords
The larynx contains two small bands of elastic tissues. They are called vocal cords. The opening between the vocal cords is called epiglottis. When we breath in or out, the glottis is open. This is the position of the production of voiceless sounds. e.g. /f/, /s/, /h/, etc are voiceless sounds in English. The sounds produced when the glottis comes together are called voiced sounds. So the main function of the vocal cords is to produce voiced and voiceless sounds.
The soft palate is also called velum. It is the roof of the mouth. It separates the oral and nasal cavity. The last part of the soft palate is called uvula. When it is lowered, the nasal sounds (/m, n, ŋ/) are produced. When it is raised, the air passes out through the oral cavity and the oral sounds (/p, t, k, s, etc/) are produced.
Þ The tongue
The tongue is an important organ of speech. It has the greatest variety of movement. It is divided into four parts: the tip, the blade, the front and the back. The number of vowels is produced with the help of the tongue. Vowels differ from each other because of the position of the tongue.
The tip of the tongue helps to produce /t, d, z, etc/. The blade of the tongue helps to produce /t∫, dÎ, ∫, etc/. The front of the tongue helps to produce palatal sound /j/ and the back of the tongue helps to produce /k, g/ sounds.
Þ The lips
The upper lip and lower lip help to produce bilabial sounds /p, b, m/. If they are held together, the sounds produced in that position are bilabial stops : / p, b/. If the lips are held together, they produce different vowels.
Þ The teeth
The teeth take part in the production of consonant sounds. The upper teeth only take part in the production of speech sounds. The lower teeth don't take part for the production of sounds. The sound produced with the help of the upper teeth are called dental sound (q, r)
Þ The alveolar ridge
The alveolar ridge is the part between the upper teeth and the hard palate. The sound produced with the tongue touching the alveolar ridge is called alveolar sounds, e.g. /s/, /t/, /d/, etc.
Producing different speech sounds depends on the movement of speech organs. It is essential to know the movement and the placement of each organ to produce particular sounds. The above descriptions and functions of the organ of speech help you to guide students to produce the consonants and vowels in a right way.