 Hello, this e-lecture introduces you to the central topics of clinical linguistics, that is, to the application of linguistic science to the study of language disability in all its forms. As a starting point, we will use the classification based on the framework provided by the communication chain in which three different kinds of abnormal language behavior can be identified. The auditory level can be associated with the so-called reception disabilities. The articulatory level can be associated with production disabilities and the central disabilities can be associated with the brain as the mediator between speaking and hearing. The major goals of clinical linguistics are to identify linguistic problems and describe them systematically in order to provide a classification of the linguistic behavior of a patient as part of the process of differential diagnosis. The role of clinical linguistics as an applied linguistic discipline can be summarized under five different headings. One of them is clarification. Clinical linguistics clarifies and classifies the various types of disability. Another is description. A major area of clinical linguistic research has been to provide ways of describing and analyzing the linguistic behavior of patients, of clinicians and others who interact with them. Diagnosis is another term, a language disability which is characterized explicitly with reference to its linguistic parameters can provide more adequate diagnostic models. An assessment based on clinical linguistic insights tells us more precisely how serious the diagnosis is. The ultimate goal of clinical linguistics is intervention, that is to formulate hypotheses for the remediation of abnormal linguistic behavior, thus making judgments about what to teach next and to monitor the outcome of an intervention hypothesis as treatment proceeds. Let us now look at the central types of abnormal language behavior and let's start with the reception disabilities. Disorders of language which interfere with the process of phonetic decoding are called reception disabilities. One of the most important disabilities is called deafness and it can be categorized broadly into two types. Conductive deafness occurs as a result of a pathological condition either in the outer ear or in the middle ear, so here we have the two sources for conductive deafness where the transmission of the sounds to the inner ear is somehow distorted. On the other hand we have sensory neural deafness which results from damage to the neural receptors of the inner ear, so here we have the inner ear related to sensory neural deafness. That is the hair cells, the organ of corti which you find here in an enlarged format. The nerve pathways to the brain, notably the auditory nerve or the area of the brain that receives sound information. Sensory neural deafness is further divided into two types, sensory or cochlear deafness resulting from the cochlear which is due to inner ear damage and the much rarer neural deafness which is due to nerve disease, typically a tumor. Deaf patients have difficulties constructing sentences grammatically even in writing. For instance they often have problems with articles, with tenses, with agreement, with prepositions and so on and so forth. Moreover their sentence structure is extremely restrictive. Let's now move on to the central disabilities, disorders of language which originate in the central nervous system are called central disabilities. There are central disabilities where the linguistic problems appear to be the result of organic pathology in specific centers of the brain. This disorder is referred to as aphasia, a disorder where language is the primary or the only aspect of behavior affected. This category which should be distinguished from other neurological problems such as dysartria or dyspraxia where dysartria for example is a phenomenon where the tongue would be quite mobile although it is not necessarily under control and dyspraxia is a phenomenon where a patient might have considerable difficulty in moving his tongue around his mouth. So from these two aphasia should be distinguished. Let us now concentrate on aphasia and look at it in more detail. Aphasia is a communication disorder caused by brain damage and it is characterized by complete or partial impairment of language comprehension, language formulation and use. There are several types of aphasia according to the location of the brain damage. Here are the most common types. One of them is referred to as Broca's aphasia. It goes back to the French physiologist Paul Broca and it is associated with a lesion in the frontal part of the human brain. The second type is referred to as Wernicke's aphasia named after the German physiologist Karl Wernicke and it is associated with lesions in the posterior part of the brain, Wernicke's aphasia. Depending on the area and the extent of the damage someone suffering from aphasia may be able to speak but not to write or vice versa, understand more complex sentences than he or she can produce or display any of a wide variety of other deficiencies in reading, writing and comprehension. Broca's aphasia is characterized by the loss of the ability to produce complete sentence structures in speech and writing. Although the individual may retain the use of nouns and verbs, pronouns, articles, conjunctions, prepositions, etc., might have been lost in all their forms. Broca's aphasics struggle to speak fluently. They hardly produce more than one word at a time but they show signs of enormous effort. Thus Broca's aphasia is characterized as non-fluent aphasia. Interestingly, comprehension is only slightly impaired but patients are often limited as far as writing is concerned. Live names for Broca's aphasia are expressive or motor aphasia or if you focus on the linguistically reduced grammar, a-grammatism. Wernicke's aphasia is a type of aphasia where patients have a lesion in Wernicke's region in the posterior part of the brain and they have extreme difficulty understanding speech produced as well as selecting phonemes or entire words with which to express their own meaning, producing errors known such as paraphasias, that is, the addition, the omission or the change of phonemes in position. The more such phonemic paraphasias accumulate in a word, the harder it is to understand to the extent that the intended word may become unidentifiable. Wernicke's aphasia speaks extremely fluently. Wernicke's aphasia is thus also known as fluent aphasia, however, speech is far from normal. Sentences do not hang together and irrelevant words intrude sometimes to the point of jargon. Alternative names for Wernicke's aphasia are fluent or sensory aphasia or if you consider the grammatical properties of speech output as paramatism. Let's now move on with the production disabilities. Under this heading, the range of disorders which interfere with the process of phonetic encoding, that is, speech production, will be introduced. There are three types of interference. One of them is referred to as disorder of fluency, that is, an interference with the sequencing of linguistic units in connected speech. Disorders of voice describe the phonetic interference with the source of phonation which will carry the linguistic message. And disorders of articulation, well, here we discuss the interference with the phonetic realization of the abstract units that constitute the linguistic system. Let us now look at these production disabilities in more detail and start with disorders of fluency. Disorders of fluency refer to specific disturbances in the rhythm and timing of speech. And not to such notions as vocabulary size. The main non-fluency syndrome is referred to as stuttering. Stuttering is a deep-rooted neurological problem affecting that part of the brain which controls the timing and sequencing of speech patterns. The degree of stuttering depends on the individuals and the situations. Six main types of stuttering can be classified respecting those who suffer from stuttering. I won't imitate them in the following. One of them is referred to as repetition. Now here you see that a person might have difficulty moving from the labiovila approximate at the beginning of where are you going to the remaining sounds in the first word where and simply repeats the labiovila approximate several times. In phenomena of sound prolongation, let's write down prolongation here, a fricative such as sir might be prolonged for a certain time before the remaining phonemes, the remaining sounds of course in a word can be retrieved. Well at the phenomenon of interjection is also well known. In response to the anticipated difficulty several interjections are produced until the word at can be produced. Well other phenomena are referred to as blocking where the airflow is obstructed resulting in a pause, erratic stress patterns resulting in strange intonation patterns and circumlocution behaviors where particular sounds are avoided. All these are types of the stuttering syndrome. Another production disability is referred to as the disorder of voice. Now voice disorders are subdivided into two types. One is referred to as disorder of phonation. It arises when something interferes with the normal functioning of the larynx so that instead of the expected range of vocal effects in pitch, the voicing of consonants and vowels and so on, noticeable distortions may occur such as hoarseness or excessive breathiness. A disorder of resonance arises when something interferes with the functioning of the adjoining cavities both beneath the glottis so down here and above so that abnormal sound effects are added to the voice quality as a whole as in excessive nasal voice for example. There are some main auditory effects likely to produce by these lesions or states. These effects can be grouped into abnormalities of pitch abnormalities of loudness and abnormalities of timbre. Finally, disorders of articulation constitute the most numerous of all speech disorders and this is the traditional center of the speech pathologist's inquiry. However, the notion of an articulation disorder is a very wide-ranging one. Several types of disorder can be distinguished, though no one knows how many there are. Here are just a few examples of an articulation disorder. And we can use the same text to illustrate these disorders. One of them, for example, can be referred to as substitution where certain phonemes with their alophones are replaced by others. So here, for example, we have the case that the alveolar approximate and the alveolar lateral consonant are replaced by a labial velar approximate. Well, and the result would then be something like whenever we were speaking about whizzy and woza somebody came up with a wobbly story about a little wabbit and how whizzy and woza tweeted this cuddly sweet animal. Another effect is referred to as distortion where the most well-known example is lisping. Now here we make an attempt at a correct sound, but the result is pretty poor. And in lisping, the alveolar fricatives, s and z, are replaced by their dental counterparts and the result will be whenever we were speaking about whizzy and woza, somebody came up with a lovely story about a little wabbit and how whizzy and woza treated this cuddly sweet animal. Well, other examples are omission and addition, for example, where particular sounds are emitted for a word and did additions where sounds or sound clusters are inserted into a word. Just listen to this example of addition. Whenever we were speaking about whizzy and woza, somebody came up with a lovely story about a little wabbit and how whizzy and woza treated this cuddly sweet animal. Okay, so that's it for now. I hope I could provide you with an overview of clinical linguistics, the application of the linguistic sciences to the study of language disability. We could not cover all details of this fascinating branch of applied linguistics, though. For further information, I recommend my e-lectures on neuro-linguistic speech perception or the auditory system to name a few. Nevertheless, I hope that to most of you, this overview was informative enough as a starting point. Thank you very much for your attention.