CHAPTER: 23 SPEECH MECHANISM

 

CHAPTER: 23

SPEECH MECHANISM

This Chapter Deals with

Speech Mechanism

Stuttering

Types of Stuttering

Normal Speech Production

Symptoms of Stuttering

Causes of Stuttering

Diagnosis of Stuttering

Treatment of Stuttering

Chances of Developing Stuttering

Speech Organs

Conclusion

Speech Mechanism

We use language every day without devoting much thought to the process, but articulator movement of the lips, tongue, and other organs—is among the subtlest and most adept of any actions performed by human beings. Here, I discuss the mechanisms of speech production, introduce functions for producing sound by controlling the movement of vocal organs, and consider models for achieving speech functions that will enable a computer to mimic a voice that it hears. Human Speech Production Mechanisms Speech is a natural form of communication for human beings, and computers with the ability to understand speech and speak with a human voice are expected to contribute to the development of more natural man-machine interfaces. Computers with this kind of ability are gradually becoming a reality, through the evolution of speech synthesis and speech recognition technologies. However, in order to give those functions that are even closer to those of human beings, we must learn more about the mechanisms by which speech is produced and perceived, and develop speech information processing technologies that make use of these functions. We use speech every day almost unconsciously, but an understanding of the mechanisms on which it is based will help to clarify the brain processes information and will also lead to the development of more human-like speech devices through the imitation of these functions by computers.

 

Speech mechanisms are primarily based on physiological structures that strengthen in man as a end result of object-directed endeavor and affiliation with different people, and that are not possible besides sure innate competencies and abilities (for example, suitable coordination of articulation, syllable-formation, and right breathing). The systemic localization of speech features in the cerebral cortex makes viable the special psychophysiological conditionality for the identical (as regards linguistic structure) speech utterances. Speech mechanisms are studied by way of the physiology and psychology of speech; and, in phrases of their linguistic shape of utterances, they are studied by using psycholinguistics and neurolinguistics. Generally the manufacturing of speech sounds we want an air-stream. The air that flows out of mouth is modified speech sounds through the motion of sure organs of our body. The speech sounds don’t come automatically. For the articulation of most speech sounds of most language, lung-air is used. This air is modified into speech sound through the operation more than a few speech organs which is regarded as ‘air circulate Mechanism’ or ‘speech Mechanism.

 Stuttering: Stuttering is a speech disorder characterized by a difficulty in producing the sounds that make up words. As a consequence, people that stutter seem to get "stuck" while pronouncing words, or have difficulty getting words out of the mouth. For this reason, it can take a long time for people with a stutter to get their message across. In severe cases, they may not be able to pronounce some words at all. Although individuals who stutter may develop emotional problems, such as fear of meeting new people or speaking on the telephone, these problems are often a result, rather than cause, of stuttering.

 Types of Stuttering: The most common form of stuttering is thought to be developmental, that is, it is occurring in children who are in the process of developing speech and language. This type of stuttering is felt to occur when a child's speech and language abilities are unable to meet his or her verbal demands. Stuttering happens when the child searches for the correct word. Developmental stuttering is usually outgrown.  Another common form of stuttering is neurogenic. In neurogenic stuttering, the brain is unable to adequately coordinate the different components of the speech mechanism. Neurogenic stuttering may also occur following a stroke or other type of brain injury.  Other forms of stuttering are classified as psychogenic. Psychogenic stuttering originates in the mind and may result from mental activity of the brain, such as that which occurs during thought and reasoning.

 Normal Speech Production: Speech is normally produced through a series of precisely coordinated muscle movements involving respiration (the breathing mechanism), phonation (the voicing mechanism) and articulation (throat, palate, tongue, lips and teeth). These muscle movements are initiated, coordinated and controlled by the brain. They are monitored through the senses of hearing and touch. Before speaking, an individual takes a breath and the vocal folds (or vocal cords), which are two bands of muscular tissue located in the voice box directly above the trachea or windpipe, come together. The voice is produced by vibrations of the vocal folds as the air from the lungs passes through them. The sound of the voice is passed through the throat and is directed into the mouth for most speech sounds, or into the nose for nasal sounds such as "m," "n," and "ng." The palate, tongue, jaws and lips move in precise ways to modify the sounds in order to make speech sounds.

 

Symptoms of Stuttering: There are some common symptoms of Stuttering which are as given below-:

• Pauses between or within words
• Repetition of sounds, parts of words, or whole words
• Having discomfort while talking
• Frequently using interjections such as "uh" or "um"
• Using words that are easy to pronounce, such as those with one or two syllables, instead of using more complex words
• Using incomplete phrases
• Using explanatory or seemingly unrelated words or phrases when conveying a thought

Some signs of stuttering are not related to speech itself, but rather result from difficulties in speaking. Signs of these secondary behaviors include movements that terminate a speech attempt. This avoidance can take the form of head jerks, finger tapping, or eye blinking.

Causes of Stuttering: Scientists suspect that stuttering has numerous causes. Many forms probably have a genetic basis, but the gene or genes that cause stuttering have not been identified. The exact mechanisms underlying stuttering are not understood.  At one time, the major cause of stuttering was thought to be psychogenic. Now, psychogenic stuttering is believed to account for only a minority of stuttering conditions. Psychogenic stuttering occasionally occurs in individuals who have some types of mental illness or individuals who have experienced severe mental stress or anguish.

Diagnosis of Stuttering: Stuttering is generally diagnosed by a speech-language pathologist, a professional who is specially trained to test and treat individuals with voice, speech and language disorders. The diagnosis is usually based on the history of the disorder, such as when it was first noticed and under what circumstances, as well as a complete evaluation of speech and language abilities.

Treatment of Stuttering: There are a variety of treatments available for stuttering. Any of the methods may improve stuttering to some degree, but there is at present no cure for stuttering. Stuttering therapy, however, may help prevent developmental stuttering from becoming a life-long problem. Therefore, a speech evaluation has been recommended for children who stutter for longer than six months, or for those whose stuttering is accompanied by struggle behaviors. Developmental stuttering is often treated by educating parents about restructuring the child's speaking environment to reduce the episodes of stuttering. Several approaches can be used to limit stuttering in children:

• A relaxed home environment that provides ample opportunities for the child to speak
• Setting aside specific times when the child and parent can speak free of distractions.
• Refraining from criticizing the child's speech, or reacting negatively to a child's problems with speaking.
• Avoidance of punishment for not speaking correctly.
• Insisting that a child continually speak the word until it is pronounced correctly
• Resisting encouraging the child to perform verbally for people
• Listening attentively to the child when he or she speaks
• Speaking slowly and in a relaxed manner; children tend to speak like their parents.
• Waiting for the child to say the intended word without pressuring them.
• Talking openly to the child about stuttering if he or she brings up the subject.

Many of the currently popular therapy programs for persistent stuttering focus on relearning how to speak or unlearning faulty ways of speaking. The psychological side effects of stuttering that often occur, such as fear of speaking to strangers or in public, are also addressed in most of these programs.  Other forms of therapy utilize interventions such as medications or electronic devices. Medications or drugs which affect brain function often have side effects that make them difficult to use for long-term treatment. Electronic devices which help individual control fluency may be more of a bother than a help in most speaking situations and are often abandoned by individuals who stutter.

Chances of Developing Stuttering: According to the Canadian Stuttering Association, approximately 1% of adults and 5% of children stutter. Stuttering affects individuals of all ages but occurs most frequently in young children between the ages of two years and six years who are developing language. Boys are four times more likely to stutter than are girls. Most children, however, Outgrow their stuttering before they become adults. Almost 80% of children who stutter recover fluency by the age of 16 years. The prognosis is favorable provided that treatment is started early. The outcome is less favorable for individuals who continue to stutter into adulthood.

Speech Organs: Human beings are blessed with a set of unique organs which make of the vocal apparatus. These organs are helpful in producing the speech in different language. A person while producing sounds; generally he takes the help of various organs. Speech is generally produced by the air stream coming out of the lungs. The speech organs help in producing sounds. There are 17 speech organs which work for producing speech. They are of the followings-:

• Nasal cavity
• Lips
• Teeth
• Alveolar ridge
• Hard palate
• Velum (soft palate)
• Uvula
• Apex (tip) of tongue
• Blade (front) of tongue
• Dorsum (back) of tongue
• Oral cavity
• Pharynx
• Epiglottis
• Larynx
• Vocal cords
• Trachea
• Esophagus

 

• Lips: The lips are most important moveable organs of speech. These are situated in the oral cavity. In our jaw, we have two lips. The upper lip is fixed but the lower lip rise and contact with upper lip. Both of the lips are very important in the production of the specific consonants and vowels.
• Teeth: Teeth also play an important role in producing speech. The main function of the teeth is to obstruct their stream which comes out from the lungs. The lower front teeth are not important except that if they are missing certain sounds e.g. S,Z will be difficult to pronounce.
• Tongue: The tongue is the main articulating and most important speech organs. By shaping the tongue differently it is possible to modify the air passage and to produce many different sounds. There are four important parts of the tongue which are-:Tip, Blade, Front and back.
• Vocal cords: Vocal cords are two small bonds of elastic tissues located in the larynx. The two bonds have a gap between them which is known as glottis. The vocal cords help in the vibration of the sound. When these vocal cords are brought together and the glottis is closed, voice sounds are produced.
• Palate: Palate has three parts which are-(i) alveolar ridge or upper teeth ridge, (ii) The hard palate and (iii) The soft palate or velum, the end of which is called uvula. The alveolar ridge or upper teeth ridge is the part of the mouth directly behind the teeth. The hard palate is the hard and prominent concave part of the roof of the mouth. The soft palate can move and can be raised in such a way as to make a firm contact with the back wall of the pharynx. In such a situation breath cannot go into the nose. Another important function of soft palate is that the whole of it is used by the tongue to interfere with the air stream.

Conclusion: Language has a very necessary social purpose, due to the fact it is mostly used for linguistic communication. It can be used in two ways. It can be spoken or written. But the medium of speech is greater essential than the medium of writing. Linguistic is a systematic find out about of language. Phonetics is a department of Linguistics and it is department dealing with the medium of speech. It offers with the production, transmission and reception of the sounds of human speech. Speech manufacturing is one of the most complicated human activities. It entails coordinating severe muscle mass and complicated cognitive processes. The location of speech manufacturing is associated to Articulatory Phonetics, Acoustic Phonetics and Speech Perception, which are all reading a number factors of language and are section of a broader discipline of Linguistics.