Process of speech production.pptx

Speech production is a complex functioning of our system.speech is an overlaid function .systems involve s in speech production already have their primary function ;their secondary functions are for speech productions.Systems involve in this process are respiratory system,phonatory system, resonatory system ,articulatory system & regulatory system.

1. PROCESS OF SPECCH PRODUCTION ANSHITA SINGH(ASLP)

2. SPEECH PRODUCTION

3. INTRODUCTION The processes by which air in the lungs is transformed into the meaningful sequence of sounds i.e. "speech". Speech is a highly coordinated fine motor act. It involves a high integration and coordination between various systems. The structures involved in speech production are the organs and structures that are a part of the systems in the human body that participate in the speech production act

4. CONT… These structures include: (a) Structures in the respiratory system: Lungs, trachea, bronchi, the rib cage, diaphragm and other muscles of respiration. b)Structures in the phonatory system: Larynx, the vocal folds in the larynx and the muscles of the larynx. c)Structures in the articulatory system: Lips, tongue, teeth, jaw and palate. d)Structures in the resonatory system: Oral cavity (mouth), nasal cavity (nose) and pharyngeal cavities (throat). e) Structure in the nervous system which act as controlling or regulating centres during speech production.

5. RESPIRATORY SYSTEM

6. RESPIRATORY SYSTEM Respiration provides a power source for speaking. The respiratory tract begins at the mouth and nose openings and terminates deep within the lungs One part of the respiratory tract is upper respiratory tract, which is formed by nasal cavity, oral cavity, pharynx and larynx. The other lower part of the respiratory tract is composed of the trachea, two bronchi and the lungs. The lower respiratory tract functions exclusively for respiration for speech production (elevation of ribs). The lungs are housed in the bony rib cage, which is formed by 12 pairs of ribs. All the ribs are joined to each other by muscles which are called as intercostal muscles.

7. CONT… The lungs are composed of elastic, non-muscular tissue surrounding the alveoli or air. The lungs are capable of expansion and contraction only by intervention of the respiratory movements activated by the muscles of respiration. Air enters the lungs through the passage of nose, pharynx, larynx, trachea and bronchi. The trachea is made up of about 16-20 rings which are made up of cartilage. There is bifurcation of last cartilage into 2 bronchi. Bronchi are divided into bronchioles. These bronchioles open into alveoli.

8. CONT… The actual gaseous exchange between the blood and oxygen rich air takes place in the lungs. The oxygen is absorbed from the air by blood circulating though capillaries of air-sacs. While at the same time carbon dioxide passes from the blood into the air sacs to be exhaled during exhalation. We speak during expiration. During the act of speaking there is quick inhalation and prolonged exhalation.

9. PHONATORY SYSTEM

10. LARYNX

11. PHONATORY SYSTEM After the air has been inhaled during inspiration the larynx acts on the exhaled air stream to create voice. This act is called as "phonation". Voice is produced by the vibration of the two vocal folds (also called vocal cords) in the larynx. The larynx lies in the anterior midline of the neck extending from the root of the tongue to the trachea. It is at the level of the third to sixth cervical vertebrae. It forms a continuous tube with the laryngeal portion of the pharynx above. It consists of a skeletal framework of various cartilages bound together by ligaments and membranes and activated by the intrinsic laryngeal muscles .

12. LARYNX It is about 44 mm length in males and 36 mm in females. Until puberty the size is more or less the same in males and females but at puberty the male larynx grows rapidly and becomes larger than that of females. Structure of larynx: The larynx is made up of skeletal framework of cartilages. These cartilages are connected by joints, ligaments, and membranes and are moved by a number of muscles. The cavity of the larynx is lined by mucous membrane. The skeleton of larynx is made up of 9 cartilages, 3 paired and 3 unpaired. The unpaired cartilages are thyroid cartilage, cricoid cartilage and epiglottis.

13. CONT… Thyroid cartilage : This is the largest cartilage of the larynx. It is shaped like a shield and can be thought as shielding the structures inside. The most anterior angle of this cartilage is commonly referred to as the Adam's apple, which can be seen on the neck in some men. Thyroid cartilage is composed of two plates of cartilage, joined at midline to form an angle. Posteriorly thyroid cartilage has two horns or cornua. The superior horn connects hyoid bone and the inferior connects the cricoid cartilage. The vocal folds extend from the interior (inside portion) thyroid angle to the arytenoids across the laryngeal cavity

14. CONT… Cricoid cartilage : It is a ring shaped cartilage, narrow in front and broad behind. It is attached to the thyroid cartilage on its upper end and to the first tracheal ring. Epiglottis : It is a leaf shaped large cartilage. It is not considered important for phonation. It is attached to the posterior cricoid elevation and the root of the tongue. It funnels the food to the esophagus and away from the laryngeal inlet

15. CONT… The paired cartilages are arytenoid cartilages, corniculate cartilages and cuneiform cartilages. The corniculate are small cone shaped cartilages that form the apex of the arytenoids. The cuneiform cartilages are small rod shaped cartilages found within the ary- epiglotttic -fold , a fold of tissue and muscle coursing from the arytenoids to the epiglottis.

16. CONT… Arytenoid cartilages : These are two cartilages each positioned on either side of the midline on the supraposterior surface of the cricoid cartilage. They are roughly pyramidal in shape. The most anterior angle of the base of the arytenoid is called vocal process. On this the vocal folds are attached. The body of vocal folds are made of thyroarytenoid muscle. There are various muscles attached to these cartilages. Some muscles are extrinsic muscles, which alter the position of the larynx. Other muscles are called intrinsic muscles, which help in phonation

17. VOCAL FOLDS The vocal folds are two muscle bands that serve to open and close the trachea by vibrating to and fro. When the vocal folds are open, free flow of air from the trachea to the oral and nasal cavities is possible. The opening between the two vocal folds is called the glottis. During normal breathing, the vocal folds are separated from each other (glottis is open), allowing air to flow easily. When the vocal folds vibrate to and fro, the air stream coming from the lungs is released into the cavities above the larynx in small air puffs. This results in the production of a complex sound called the laryngeal tone (phonation).

18. CONT… The laryngeal muscles play an important part in opening and closing the glottis. The glottis can be completely open when the vocal folds are away from each other and it can be completely closed when the vocal folds are tightly closed against each other. The laryngeal muscles can also close the glottis only lightly so that the vocal folds can be parted by air pressure from the lungs, causing rhythmic opening and closing of the glottis for phonation.

19. RHYTHMIC CYCLE During phonation, the vocal folds follow a rhythmic cycle: vocal folds come together . air pressure below the glottis is increased. due to the pressure the vocal folds open up. emission of a puff of air. vocal folds close again due to the decrease in air pressure and constant muscle tension. When the vocal folds close, air pressure below the glottis again increases and the pattern is repeated. The resulting periodic puffs of breath (air) give the sound of voice.

20. FUNDAMENTAL FRQUENCY The frequency at which the vocal folds vibrate (number of vibrations per second) determines the fundamental frequency of the voice. The fundamental frequency of the voice depends on an interaction between the height of the larynx in the neck and the length, thickness and tension of the vocal folds. The vocal folds of males vibrate at a lower frequency while that of females vibrate at a higher fundamental frequency. The frequency of vibration is the highest in children. The fundamental frequency of vibration decides the individual's vocal pitch.

21. RESONATORY SYSTEM

22. RESONATORY SYSTEM The physical (acoustic) changes made in the original vocal tone are called resonance phenomenon. The sound waves created by vibration in the larynx travel up through the other structures of the airway, primarily the hypopharynx, the oropharynx, oral cavity, nasopharynx and nasal cavity. The place where the velum meets pharynx is the beginning of nasopharynx, which leads to the nasal cavity. The site is known as the "velopharygeal port ".

23. CONT… When the velum hangs down during breathing, it connects nasal cavity with oral cavity. This nasal-oral coupling is required for nasal resonance When the velum is lifted by the muscular action the velopharyngeal port is closed. This closed position is required for the oral resonance of all vowels and consonants except nasal sounds

24. ARTICULATORY SYSTEM

25. ARTICULATORY SYSTEM

26. ARTICULATORY SYSTEM After phonation, that is the production of voice, the next action is to create specific speech sounds needed to speak. This is done by the articulatory system. The production of various speech sounds such as consonants and vowels is done by the articulatory system. The structures in the oral cavity which are responsible for articulation of the phonemes are called the articulators. These include the tongue, lips, teeth, lower jaw (mandible), the hard palate and the soft palate (velum). The articulators can be classified into two types :

27. CONT… Active articulators are the organs in the oral cavity which take an active part in articulation. These include the parts which move to change the shape of the vocal tract. Active articulators in the vocal tract are lips, tongue, mandible and soft palate. Passive articulators are the organs in the oral cavity which do not move but take part in articulation by providing a surface for contact by the active articulators. The alveolar ridge (gums just behind the upper front teeth), hard palate and teeth are passive articulators

28. Role of various articulators 1. Tongue : The tongue is a highly mobile muscular organ arising from the floor of the mouth. It occupies most of the space in the oral cavity. Muscles within the tongue enable it to change its shape easily. Other muscles coming from various sites allow important movements such as tongue upward movement, protrusion elevation or outward movement, retraction or backward movement and lateralization c to side movement. The tongue can be divided into its tip, middle portion and back. The tongue is the most important structure for articulate speech .

29. CONT… 2. Lips : The lips are made up mainly of facial muscles which make it possible for them to spread, round, come together or pucker. They are the most visible structures of the mouth and are also used in various facial expressions. The lips can close to stop the air stream as in the production of sounds such as p in parrot, b in bag and m in mummy. The lower lip can touch the upper front teeth for production of sounds such as f in father and v in van. Rounding the lips and changing the degree of lip opening contributes to the production of vowel sounds such as u in pull and o in four

30. CONT… 3. Teeth : The teeth that are most important for production of speech sounds are the four front teeth in each jaw-lower and upper. They are used in the production of sounds such as f in father, v in van, s in six and z in zebra. 4. Alveolar ridge : This is the gum ridge just behind the upper front teeth. This is an important point of contact by the tongue for sounds such as t in ten, d in dog, n in nose, I in letter, s in six and z in zebra. 5. Mandible : The lower jaw or the mandible helps in opening or closing of the mouth (oral cavity). It also changes the size and shape of the oral cavity required for different vowels. Mandibular movement is also important in maintaining optimal vocal resonance.

31. CONT… 6. Palate : This is the structure separating the oral and the nasal cavities. It extends from the alveolar ridge to the back of the mouth. The part of the palate just behind the alveolar ridge is bony and hard. This is called as the hard palate. The part toward the back of the oral cavity is soft, muscular and mobile. This is known as the soft palate or the velum. The hard palate helps to direct the air stream toward the front of the mouth during consonant articulation. It also contributes to vowel resonance. It provides various points of contact by the tongue for articulation of different speech sounds.

32. CONT… The soft palate is a mobile structure and can be raised or lowered. When elevated, it is in contact with the wall of the throat (posterior pharyngeal wall), thus separating the oral cavity from the nasal cavity. When it is not elevated, air can flow from the oral and pharyngeal cavities to the nasal cavity. This is required in production of nasal sounds like m in mat and n in nose. The velum also serves as a point of contact for the back of the tongue during production of sounds such as k in kite and g in go. Any structural defect such as cleft palate will have its effect on speech.

33. REGULATORY SYSTEM

34. REGULATORY SYSTEM The role of nervous system is to control the ongoing speech activity. It is our brain that allows us to understand and use the complex structure of language. The system investigates and transmits neural impulses that stimulate our muscles to contract. At the same time muscle contraction and movements about the joints initiate neural impulses, and they in turn travel back to the coordinating centres of the brain to "tell it" what is happening and if things are happening as planned. The nervous system is divided into a central nervous system and peripheral nervous system .

35. CONT… The central nervous system consists of the brain and spinal cord. The brain consists hemispheres which have different lobes such as frontal lobe, temporal lob parietal e, lobe, occipital lobe, cerebellum and brainstem. The brain stem finally leads to the spinal cord The peripheral nervous system is divided into voluntary part (cranial nerves and spinal nerves) and involuntary part (autonomous nervous system). There are specialized centres in the brain respectively for the various speech and language functions

36. CONT… The functions of these centres are discussed below: The broca's area : It is located on frontal lobe of the left hemisphere. The Broca's area is responsible for motor speech. This area is responsible for originating, planning and carrying out the transmission of messages. Damage to the area leads to a problem in production of speech and comprehension of spoken language may also be affected but to a lesser degree. The wernike's area : Wernike's area is located in the temporal lobe of the left hemisphere in most individuals. This area is responsible for comprehension (understanding).

37. CONT… Cerebellum : The role of cerebellum is coordination of movements required for production of speech. Cranial nerves : The command centres in the cerebral hemispheres relay orders to the specific muscle groups of speech production and receive information from the sense organ of hearing through the peripheral nervous system. This is done through the cranial nerves. There are 12 pairs of cranial nerves. They emerge from the base of the brain and are named primarily according to the function they serve. For the control of speech mechanism the fifth ( trigeminal ), seventh (facial), ninth (glossopharyngeal), tenth (vagus) and twelfth (hypoglossal) nerves play important roles. The eight cranial nerve is the auditory nerve, which is responsible for hearing and balance.