Pure Word Deafness and Indicators on Speech Perception - Essay Example

PURE WORD DEAFNESS AND INDICATORS ON SPEECH PERCEPTION – A LITERATURE REVIEW Table of Contents Introduction 3 Pure Word-Deaf (PWD) Patients 3 Pure Word Deafness and Speech Perception 4 Speech Perception, Pattern in Speech Comprehension and PWD 5 Neurobiology of the Brain and Speech Recognition 7 Practical Application of PWD and Lessons for Speech Perception 9 Conclusion 11 References 13 Introduction Linguistics traditionally provides a framework and system through which people’s perception of spoken words and languages is studied for improved and enhanced comprehension. This has culminated in numerous models and systems that are applied in a wide array of situations and contexts. The purpose of this essay is to conduct a literature review on how word-deaf patients relate to the various models of speech perception. Obviously, speech perception models are put together to explain how people internalise and interpret spoke words. Hence, there is a question of how word-deaf patients react to these situations and matters. How do word-deaf patients cope and how they understand and comprehend important ideas and concepts. Pure Word-Deaf (PWD) Patients “Pure word deafness (PWD) is a rare auditory disorder that is characterized by a selective deficit in comprehending spoken words, while the identification of nonverbal sounds remains intact.” (Zhu, et al., 2010, p. 843). This is a form of brain damage that makes it challenging for a person to comprehend words that are spoken to him or her. Pure word deafness is characterised by a selective problem of accessing language sound patterns and word forms (Rickheit & Strohne, 2012). This means that the sound patterns and variety of words presented to a person suffering from this condition are not understood by such an individual. This is distinguished from cortical auditory deficit by the fact that pure word deaf persons can hear and comprehend music and environmental sounds (Kaga, 2013). Thus, by implication, pure word deaf patients can hear and understand music as well as environmental sounds around them. However, they cannot hear words spoken to them by a third party. Pure deafness is scientifically known as Auditory Agnosia for speech and verbal communication (Feinberg & Farah, 2012). This expresses the difference and inconsistency in comprehension of verbal discourse and the lack thereof of verbal auditory recognition. “The underlying problem of a person with word-sound deafness is at the stage of extracting the phonetic features from the speech input such that the patient has problems discriminating between widely variant words (the severe form) or between similar sounding words” (Ingram, 2014, p. 166). This means that the person with word deafness has some challenges in decoding the phonetic and sound elements of speech and cannot sort it out for onward interpretation and understanding. Pure Word Deafness is caused by a brainstem lesion which is a complication that often comes with stroke and other conditions that makes it difficult for patients to hear and understand some selected forms of information for onward assimilation (Godefroy, 2012). However, most authorities assert that PWD is a very rare condition that does not often occur in medical cases (Feinberg & Farah, 2012; Godefroy, 2012; Rickheit & Strohne, 2012). Pure Word Deafness and Speech Perception PWD is viewed as a unique and distinct aspect of hearing inabilities and hearing incapability. This is because the patients seem to exhibit characteristics that are so different and distinct from patients with other forms of deafness. Evidence shows that PWD is one in which patients do not have hearing impairments but they are severely limited in imputing information to certain parts of their brain (Gibbons, et al., 2012). Therefore, in the absence of presenting information to these vital parts of the brain for onward processing and evaluation, there is a major trend whereby patients tend to be incapable of hearing and understanding words that come with the speech and the communication. Evidence also shows that in patients with PWD, linguistic skills remain intact and strong but there is degraded speech perception which results in impaired repetition and comprehension (Robson, et al., 2012). This confirms that the situation is one in which the patients are limited in their ability to understand and internalize the words of a given communication. They do not tend to have a part of their brain that filters the information and gather the information. This shows that in linguistics, the ability of an individual to hear and understand information transcends just the ability to hear. There is more to it and this includes the ability of the brain to rightfully sort out information and classify it in order to get the other aspects of the mind to interpret it and make use of the information or words. In PWD, the neural language system is affected and information gathering from speech is not correctly done (Robson, et al., 2012). This indicates that the neurology of the brain is in some way affected and influenced when a patient has a case or issue with PWD. And this leads to major problems and major challenges with the way and manner in which an individual understands and makes sense of information presented to him or her. Speech Perception, Pattern in Speech Comprehension and PWD Speech perception is a complicated approach and system and includes word discrimination and right hemisphere helps in lexical perception (Posni & Remez, 2012). The information given to a person is critiqued and analysed by different parts of the brain to get the individual to act on the information that is granted to him or her. Studies have shown that there are five key pointers in the neuropsychology of language acquisition and speech decoding, which includes: 1. Auditory analysis system extracts phonemes and other sounds in speech wave 2. Auditory input lexicon contains information in spoken words that are familiar to the listener; 3. Word meaning are stored in a semantic system 4. Speech output lexicon provides the spoken form of word with meaning 5. The phoneme response buffer provides distinctive speech sounds (Eysenck & Kean, 2014) Therefore, when information is presented to an individual, the first thing that is done is an auditory analysis of the information. This is done by the extraction of phonemes and other speech elements. This is a basic sorting of information by examining the phonetics and the patterns of the brain and conducting various levels of evaluations of the worth of the words presented to the individual. Afterwards, the individual moves the information to the stock of words and similar ideas and concepts linked to the words he just heard. This will enable him to decipher the patterns and the trends in the information and the spoken words. The listener is able to get important meanings and basic understandings of the words. When the meaning is deduced, it is stored in the memory of the individual and this informs various forms of conduct that relates to the information. This updates the memory and stock of information that the individual has and gets the person to work on the information that is granted to him. Speech output lexicon refers to the obvious reaction to the information by also forming words and presenting it to the individual. The phoneme buffer is the system through which a person gets differing speech sounds and speaking limits in order to provide a fitting response. The speech and comprehension model shows how the human brain works and reacts to information that is given to it. This gives an explanation of how and why we take in information and utilise it to achieve various goals and ends. The study if PWD shows a clear example of situations whereby the inability of people is identified. This includes the process whereby some auditory systems in the neurological system of a person is limited and cannot meet its goals. Hence, a patient might not be able to fully appreciate the extent and scope of new information that is given to the person through speech and words. Instead, the individual can understand other sound patterns like songs and music amongst others in order to act or react to it. This shows that the mind and the brain is compartmental and there are different processes and activities that go on to help a person to achieve comprehension of information that is handed to him or her. Therefore, although people might suffer PWD, they retain reading, writing and spontaneous speech abilities (Gibbons, et al., 2012). Information from speech is therefore evaluated and synthesized in a more comprehensive and distinct manner. This shows that information in speech is not simply gathered without any kind of effort or work by the brain. Neurobiology of the Brain and Speech Recognition Speech perception model includes the following variables: syllable discrimination or identification and perception which lead to natural language comprehension (Hickok & Poeppel, 2012). This therefore indicates that the human brain is able to discriminate and evaluate words and provide a framework for examining and providing some kind of meaning or value to whatever is fed to the human mind. There is an entire and a unique auditory conceptual interface that works with various components to form the human mind (Hickok & Poeppel, 2012). Therefore, speech is examined and critiqued by the different components of the auditory conceptual interface and this is used to provide important meanings and conclusions in matters. There is the auditory motor interface which feed information to the mind and this is connected to the sound-based representation of speech and the motor articulatory system (Hickok & Poeppel, 2012). They both have separate functions that come together to help to acknowledge word, speeches and other sounds (Hickok & Poeppel, 2012).The auditory motor interface helps to examine and accept sounds. Therefore, the sound representation of speech is internalised and given meaning by this completely different brain part (Hickok & Poeppel, 2012). On the other hand, words and other sound based interpretation systems are conducted by the motor articulatory system. This system helps to put together words and try to present it to the other brain units for onward processing and evaluation. PWD is therefore a situation whereby the motor articulatory system is damaged. Due to this, the words that are presented to an individual are not understood by the individual. On the other hand, the individual understands and appreciates the sound representation because the auditory motor interface is working. Hence, the brain’s function of sorting and sifting through information relating to sounds is working whilst the part that gathers words and sends them to the other part of the mind for interpretation and comprehension is not working. Hence, the patient is able to understand the sounds and other aspects of information that is presented to it. It must be added that the fact that information cannot be processed by one part of the mind does not cause the individual not to understand or process other further information. There is the ability of the mind to retain and hold on to its linguistic abilities and the individual in question to understand certain things in linguistics intercourse. Therefore, the individual is able to understand and hear sounds and some auditory patterns, however, the ability to understand words and hear speech in a clear-cut manner and fashion is eliminated (Poeppel, 2010). Evidence shows that there is a problem with the acoustic information and the integration of this into the linguistic computational system of people with word-deaf conditions (Poeppel, 2010). This explains why such persons can appreciate music and other forms of communication that does not follow the logic of spoken words. Indeed animals do not have that competency to decipher words. However, they are also able to hear various sounds and make meaning of it, especially in situations relating to danger. Most animals are able to hear sounds of dangerous creatures and circumstances like fire and move away from it as a means of survival. Therefore, the motor articulatory system helps the human mind to decipher and understand words and tonations as well as other sentences and interpret it in order to aid specific action and conclusions from the set of information that is given through speech. Empirical research indicates that PWD is mediated by the posterior superior temporal cortex in both hemispheres (Poeppel, 2010). Therefore, where there is a problem or issue with this brain function, an individual is limited in many ways and cannot perceive or break down words and ideas in the most ideal and appropriate manner. Hence, the person ends up having a complication in understanding information. This has to do with a function of the brain rather than the circumstances around which a person hears or makes auditory reception. Practical Application of PWD and Lessons for Speech Perception There have been some evidential proof that the treatment of patients with PWD provides important pointers and measures that can be used to understand and evaluate changes in the way people think and analyse information that is presented to them. One of the direct application for the use of PWD is the concept of learning how children perceive and appreciate new words and understand language as and when they are presented to them (Slevc, et al., 2011). In PWD, patients preserve their decoding abilities and hearing abilities, but cannot hear the words being spoken to them (Slevc, et al., 2011). Therefore, in children and people who speak foreign language tend to hear what other people are saying, but they have an impaired ability and competency to internalise these words and make meaning of it. Therefore, the idea of promoting language learning is to ensure that the appropriate part of the brain of a language learner is activated in order to get him or her to appreciate the new language. The left hemisphere damage is generally responsible for the deficit in the perception of temporary stimuli. PWD occurs when the left hemisphere of the brain is damaged or affected negatively. This implies that the left hemisphere provides a process and system that breaks down words and provides meaning to them in an individual. Treatment for PWD includes the use of various computer software and systems like Fast ForWord which provides a basis through which the patient is treated with two different approaches (Slevc, et al., 2011). First of all, the program enables the patient to hear fast speech that is presented quickly in the form of songs or other deliveries. This is presented fast and the sound is comprehended by the patient. Secondly, there is the presentation and repetition of words that are familiar to the patient. This is done by presenting a word or a few words and providing a conscious and continuous presentation of the information about that particular item. Another approach is the use of pictures as a means of providing the patient with some information and some clues on what is being discussed. This is a process through which visual identification is used as an aid to help a patient who cannot comprehend speech is given information and assistance and guidance. This is complemented by the various approaches of communicating with the patient which s/he can understand. This includes writing and singing in order to get the patient to get a fair idea and understanding of what is being communicated or presented. There is also cross-modal input which is a process whereby a patient with PWD is encouraged to hear and perceive information (Robson, et al., 2012). This is done through the use of various communication methods and communication processes and systems that allow the patient to understand and accept information. Therefore, communication and speech perception is done through the brain and its component that sifts information and gives meaning to words. Where this is not available and that part of the brain is not functioning, there is the need for the patient to be given aid and other form of care and close contact in order to get them to contribute to the situation and understand what is going on in the situation. Conclusion Word-Deaf Patients have issues with the processes whereby people cannot process words and information. This provides a lot of information about the speech perception process of human beings. PWD is a sign that linguistics go beyond just the ability to hear information that is presented to people. It shows that human beings are able to understand and perceive words because of a number of privileges that we have in our brains. This is what sets humans apart from animals. The literature review identifies that the human brain is compartmentalised. It includes various parts and components that help a person to analyse phonemes and other sounds in speech-wave. This information is decoded in order to get people to compare information that is presented in words and compare it with the stock of words that the individual has in his mind. The process allows a person to decode message and evaluate information in order to make meaning of spoken words. PWD occurs when the parts of the information presented to people is deduced and evaluated in the brain for onward comprehension. Where there is no ability for this function in the left side of the brain to deduce and make meaning of words, that individual in person cannot comprehend information and falls into the condition of PWD. PWD has a symptom of the failure to achieve syllable discrimination and identification of tones. This causes the comprehension and perception of natural language to be halted and limited. In terms of neurology, authorities identify that the auditory interface of a person has two components. One component links the hearing system of people to the sound representation whilst the other links the hearing system to word representation and speech. PWD shows that in cases where the motor articulatory system which is responsible for perceiving the word presentation of information is impaired, an individual cannot make meaning of words. It is only sound that a person can perceive and internalise. Hence an individual can achieve other linguistic functions but cannot perceive or understand words. The treatment of PWD also shows that patients are able to get around the limitation of perceiving information where there are visual and other forms of repetitive speech combined. In this process, the patients’ visual functions are engaged through the presentation of pictures and other forms of information like songs to provide them with important guidelines and clues. This is comprehended by such persons and they are able to make meaning of them. This confirms the fact that the human brain provides important components and competencies that enable a unique function of understanding words to go on as a part of communication. References Eysenck, M. W. & Kean, M. T., 2014. Cognitive Psychology: A Students Handbook. 3rd ed. New York: Psychology Press. Feinberg, T. E. & Farah, M. J., 2012. Patient-based Approaches to Cognitive Neuroscience. 2nd ed. Boston: MIT Press. Gibbons, C., Oken, B. & Fried-Okena, M., 2012. Augmented input reveals word deafness in a man with frontotemporal dementia. Behavior Neurology, 25(2), pp. 151-154. Godefroy, O., 2012. The Behavioral and Cognitive Neurology of Stroke. Cambridge: Cambridge University Press. Hickok, G. & Poeppel, D., 2012. Towards a Functional Neuroanatomy o Speech. [Online] Available at: http://www.utdallas.edu/~otoole/HCS6330_F12/09_hickok.pdf [Accessed 21 May 2015]. Ingram, J. C. L., 2014. Neurolinguistics: An Introduction to Spoken Language Processing. 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