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the utterance of vocal sounds conveying ideas; the faculty of conveying thoughts and ideas by vocal sounds. The process is controlled through motor speech areas located in the frontal lobe of the brain.

The Mechanics of Speech. The voice originates in the larynx, which is in the upper end of the air passage to the lungs and is behind the thyroid cartilage. The larynx, in cooperation with the mouth, throat, trachea, and lungs, works on the same principle as musical instruments such as organs and oboes, in which air is forced over a thin reed to produce sound. The vocal cords, two reedlike bands, are attached at one end to the wall of the larynx behind the laryngeal prominence or “Adam's apple”; the other ends are attached to movable cartilages. When the voice is not being used, muscles move these cartilages outward and hold the vocal cords against the sides of the larynx so that breathing is not obstructed. When a person starts to speak, sing, grunt, or shout, the ends of the vocal cords connected to the cartilages are brought across the larynx, so that they partly obstruct it. As air is forced through, the cords vibrate, producing sound waves, which are what is known as the voice.

In speaking, the size and shape of the mouth and pharynx are varied as the sound goes through, by means of muscles of the mouth, throat, and tongue. Vowel sounds are initiated in the throat and are given their distinctive “shapes” by movements of the mouth and tongue. Consonants are formed by controlled interruptions of exhaled air.
Volume, Pitch, and Timbre. The voice itself has three characteristics: volume, pitch, and timbre (or quality). Volume depends on the effort made in forcing air through the vocal cords. The pitch of the voice depends on the amount of tension placed on the vocal cords, and on the length and thickness of the cords. Children's and women's vocal cords are short, giving them higher-pitched voices. A man's are longer and thicker and his voice is deeper. Timbre is affected by the size and shape of the individual's various resonating chambers (mouth, pharynx, chest, and others) and the way they are used. Bones in the head and chest also contribute to the quality of a voice. By long training in the use of the voice, singers are able to alter and control the mouth, throat, and chest cavities to produce a wide range of harmonics or overtones.
Speech Defects. Over 100 muscles are involved in the utterance of a simple word, and the construction of a simple sentence is a feat so complicated that it is beyond the capacity of any animal except the human being. The process of learning to talk is obviously a difficult task for children, and it is not surprising that 5 to 7 per cent of children reach adulthood with a serious speech disorder.

The baby learns to make specific sounds with the voice by babbling and cooing. Gradually he or she becomes able, more or less unconsciously, to put these sounds together to form intelligible speech in imitation of parents and other speakers in the environment. This complicated process is sometimes disturbed if the child has congenital physical defects, illness, or psychologic difficulties. As a result, speech disorders may occur.
Congenital Causes. Prominent among the congenital defects that may cause speech problems are cleft lip and cleft palate. These abnormalities are evident at birth and should be corrected by surgery at an early age. Another congenital defect is ankyloglossia (tongue-tie), abnormal shortness of the frenulum of the tongue. This condition, which if uncorrected may cause lisping and other awkwardness, is easily corrected by surgical cutting of the frenulum as soon as the difficulty becomes evident. Congenital deafness will prevent a child from learning to speak in the usual way and may result in mutism. However, if the speech mechanisms are normal, the child can be taught to speak by a speech therapist. Malformations of the nasal passages, larynx, or other parts of the voice-producing tract may cause oddities in the sound of the voice. Such defects also can be corrected in many cases by minor surgery.
Other Causes. By the age of 5 or 6 years most children have mastered the basic art of talking. Serious difficulties that persist or appear for the first time after this age, and that are not due to congenital defects, are likely to arise from illness, injury, or a psychologic disturbance. Damage to speech centers of the brain by multiple sclerosis, syphilis, or parkinson's disease, for example, may cause speech to be singsong, explosive, mechanical, or slurred. In such instances improvement of speech follows treatment of the basic disorder. Poor alignment of the front teeth also may interfere with proper speech. Speech defects of psychologic rather than physiologic origin include stammering and stuttering.
speech disorder defective ability to speak; it may be either psychogenic or neurogenic. See also aphasia, aphonia, dysphasia, and dysphonia. Called also lalopathy and logopathy.
esophageal speech speech produced by expelling swallowed air across one or more constrictions in the pharyngoesophageal segment; used after laryngectomy.
explosive speech loud, sudden enunciation, occurring in certain brain diseases.
speech and language in the omaha system, a client problem in the physiologic domain, defined as articulated vocal sounds, symbols, signs, or gestures used for communication.
mirror speech speech in which the order of syllables is reversed.
pressured speech logorrhea.
scanning speech speech in which syllables are separated by pauses.
telegraphic speech speech consisting of only certain prominent words, without others such as modifiers; it is typical of children around age two but in older persons it is a form of agrammatism.


A form of aphasia characterized by an inability to construct a grammatical sentence and the use of unintelligible or incorrect words; caused by a lesion in the dominant temporal lobe.


A type of expressive aphasia characterised by a disintegration of spoken syntax, resulting in laboured speech peppered with substantives and short phrases. Function words such as verbs are omitted—resulting in so-called telegraphic speech—or are confused with each other more often than content words.
Aetiology Broca’s aphasia, traumatic brain injury.


Neurology A condition characterized by a dissolution of spoken syntax, which becomes laborious and reduced to scattered substantives, and short phrases; in agrammatism, 'function' words are omitted or confused with each other more often than 'content' words See Jargon agrammatism.


A form of aphasia characterized by a reduced ability to understand or produce most grammatical markers, usually related to severe expressive aphasia.
References in periodicals archive ?
It has been well established that as a matter of fact, Broca's aphasia includes two different abnormalities: (a) a motor production defect characterized by decreased fluency, abnormalities in the speech kinetic melodies, articulation slowness, and so forth, referred to as apraxia of speech, and (b) a disturbance in the use of grammar usually known as agrammatism [40, 46, 51, 84].
Code, "First in, last out?: the evolution of aphasic lexical speech automatisms to agrammatism and the evolution of human communication," Interaction Studies, vol.
Neuropsychological testing revealed that the patient's speech consisted of phrases, without noticeable agrammatism, but predicative: In the production of speech there was a predominance of verbs (see Table 4).
Crosslinguistically, sentence production difficulty in agrammatism is often characterized by exceptional difficulty producing certain types of morphosyntactic structures, such as tense marking, relative to other structures, such as agreement and mood marking (e.g., in English [10-13]; in Hebrew [14]; in German [15]; but see conflicting results in [16]; in Spanish [17, 18]; in Dutch [19, 20]; and in Greek [2123]).
Accounts of Tense Production Deficits in Agrammatism. Given the prominence of tense deficits in agrammatism, there are numerous tense-centric theoretical accounts of agrammatic aphasia [12,14,15,19].
Another family of tense-centric accounts of agrammatism draws attention to the fact that, in addition to its morphosyntactic role, verb tense interfaces with semantics of the event.
To summarize, a variety of accounts have been proposed to characterize the difficulty with production of tense morphology in agrammatism. A majority of the more recent accounts incorporate some reference to the semantics of time, one account proposes further dissociation within temporal morphology, and some accounts allow for performance variation based on task processing demands.
Few studies of agrammatism have compared perfect and imperfect aspect to glean the influence of grammatical aspect on sentence production (but see [29]).
Among specific topics are the fluidity of recursion and its implications, recursion and iteration, just how big natural languages are, a Bayesian exploration of how recursive language is, an evolutionary perspective on clauses that refuse to recur, a proposal for distinguishing the differences between human and non-human animal learners, kinds of recursion in Adyghe morphology, cognitive grouping and recursion in prosody, and recursion in severe agrammatism.
As evidenced by his performance on the Western Aphasia Battery (WAB) [8] (Aphasia Quotient = 81.6/ 100), the subject displayed a mild Broca's aphasia and relatively spared auditory comprehension in the context of nonfluent verbal output characterized by agrammatism, word retrieval failures (anomia in discourse and confrontation naming), and motor articulatory difficulty.
Theoretical motivation for the cross-language study of agrammatism. In Agrammatic Aphasia, A Cross-Language Narrative Sourcebook, vol.
Agrammatism: behavioural description and neurobiological explanation.