Hearing Impairments and Treatments of the Auditory System - Research Paper Example

Hearing impairment is a prevalent disease that involves mostly both ends of the spectrum, from the infants who are still undiagnosed, to the adults, and the aging populating. In Canada, it is allegedly one of the fastest growing chronic conditions in the Canadian population, with presbycusis and noise-induced hearing loss being two of the most common etiology (Anon, 2010). In the American population, studies have shown that there also concomitant demographic characteristics that increase the risk for developing hearing loss such as smoking, noise exposure and cardiovascular risks (Agrawal, 2004). Newborn screening for hearing loss has been done on 90% of infants as of 2005 to 2006 with some 30% lost to follow up after several years (Gaffney, 2010). Hearing impairment has also been noted to be more prevalent among subjects 40-49 years old and more common in white males than in females, and even among blacks (Polley, 2008). In a statistics study done in Canada, it was shown that approximately more than one million Canadian elderly have been reported to have hearing impairment, and these numbers may actually be greater since there is a tendency to underreport the cases (Anon, 2010). It is also becoming a trend that the age wherein hearing impairment is diagnosed has become increasingly younger due to noise damage. Hearing impairment in childhood may be classified as hereditary genetic or acquired. A common result of undiagnosed hearing impairment in this group is abnormal speech development. Of the genetic cases, most of them are monosynaptic, meaning that only the hearing is affected, with no associated anomalies (Probst, 2006) Conductive hearing loss can be treated or improved by surgery, and medical treatment rarely improves hearing impairment. Hearing aids are advised for patients with moderate to severe hearing loss, while cochlear implants are used for profound hearing loss and for those not benefitting from hearing aids (Probst, 2006). Different treatments are available for the pediatric population, and this includes behind-the-ear hearing aids, and if the defect is bilateral, the patient can avail of bone conduction hearing aids. For those patients with cochlear damage and with auditory nerve unresponsive to stimulation, cochlear implants may be provided, and is done via cochlear implantation surgery, a low risk procedure (Probst, 2006). In adults, most cases are that of the age-related presbycusis, and this is often managed with hearing aids. In many cases, recently, however, much younger patients are being diagnosed with hearing impairment secondary to chronic exposure to industrial noise or any form of noise pollution that can cause damage to the ears if not prevented. This is a different group from the older adult population whose hearing impairment is thought to develop from gradual degeneration of the cochlea at the base, which results in hearing impairment at high frequencies. Rehabilitative options available include surgery for conductive hearing loss, hearing aids, active middle ear implants, cochlear implants, vibrotactile aids, and other assistive devices. Other options for management include lip reading, speech improvement, selective listening techniques and proper use of hearing aids, for which the patients can be trained. According to the study done by Corna, et.al., introduction of mastery and self-esteem further reduced the size of the effect of reporting a decline in hearing…, thus these two may have an impact on the development of the development or non-development of psychological distress in hearing impaired older adults (Corna, 2009). With this, it can be seen that hearing impairment may be disabling not only because it is physically necessary to adjust to the condition, but also because of the distress it causes the disabled patient who has to adjust his life again. The World Health Organization has also recognized that even the ageing-associated changes in hearing ability, known as presbyacusis has its social impact on the disabled individual. “…The problem of this group becomes very essential social question. One of very important vital difficulties of that particular age is the problem with verbal communication, caused by the hearing disorders, very often stated in the older population. The hearing disorders (presbyacusis) are characterized by difficulties in speech understanding, the so called "social deafness", which often is a cause of psychical changes and isolation of persons with such hearing impairment. Because of its character, presbyacusis is very difficult in hearing rehabilitation” (Beteljewski, 2006). Several studies have been done regarding hearing aids, and this can be either unilateral or bilateral aids. One study done at the University of Texas at Southwestern Medical Center and Childrens Medical Center Dallas did a review of some analysis of medical records of children 1-17 years of age diagnosed with sensorineural hearing loss. They found out that the imaging modality of choice, which was the Computer tomography scan failed to show the soft tissues which would be responsible for the conduction of electrochemical stimulus necessary for hearing conduction. They found 170 children that were included and of these, a certain 59 percent had bilateral hearing loss and 49 percent had unilateral hearing loss after they underwent MRI studies between 1996- 2002 (Maclay, 2002). They concluded the study with a recognition that although CT and plain radiographs were useful in diagnosing bone defects that could result in hearing impairment, the soft tissue structures in the ear need to be studied as well for any defects. This was shown by the result of the study wherein 40 percent of the study population was diagnosed with inner ear abnormalities, with 32 percent of the total population having cochlear abnormalities. They also found that children with moderate, severe or profound hearing loss in one ear had more inner ear abnormalities than children with hearing loss of the same severity in two ears (62 percent vs. 38 percent) (Maclay, 2002). Another study compared the result of Bone-anchored hearing aids (BAHA) in contrast with contralateral routing of signal amplification (CROS). The study showed that there was significant increase in benefits with monoaural hearing when using BAHA than with CROS. Some subjects who already used CROS opted to try BAHA. The benefit was seen more in patients with moderate sensorineural hearing loss, with greater improvement especially in background noise and speech understanding (Mei-Lin, 2006). These studies also took into account the patient’s satisfaction with the aids being used and the benefits in different backgrounds and speech improvement. There was no mention of the quality of life, only the perceived improvement in the hearing in different environments. In a study done on Nigerian elderly patients, there was a noted correlation between the levels of folic acid deficiency and hearing loss in high frequencies. The study was based on the presumption that some micronutrients have a role in the cellular metabolism, nervous system, and vascular function. The study also made it a point to exclude patients who had chronic illnesses like hypertension, diabetes, ear diseases, ear infections, ear trauma, ear surgery, or exposure to noise and ototoxic drugs such as aminoglycosides, antibiotics, and diuretics, which may affect the auditory system. This was a study rooted in the fact that many groups, especially the underserved populations also suffered from a lack of proper nutrition, and this lack may possibly contribute to significant deficiencies in important vitamins like folate (Akeem Olawale Lasisi, 2010). Although there have been more studies related to the hearing aids and other devices and surgical interventions that may be of benefit to the population, it also important to look at the implications of this hearing impairment on the persons who are diagnosed based on their quality of life. For the population of undiagnosed children, studies in relation to speech development, or a tendency towards a delay in normal functioning, or a notable poor academic performance may be signs of hearing impairment. This is similar with the aging population, wherein communication is also the most affected aspect of the changes notable once hearing impairment sets in. A study done on Brazilian population noted that “…the hearing apparatus is one of the most important factors related to the development of oral communication. A failure in this system can start a chain reaction, that is, a hearing impairment causes great communication difficulties that in its turn bring about deterioration in life quality. Early diagnosis and intervention in aging-related hearing loss are paramount in order to provide the elderly with a good life quality…” (Revas, 2007). Emphasis on early interventions for adults after early diagnosis of the hearing impairment is a known fact that can help to improve the quality of life of this population, especially with the advent of technology that can be of use to alleviate of help with the adjustment period to the impairment. With early diagnosis, the patient is then better able to adjust regarding his condition, and not feel hopeless about it. Also, there is a more awareness on the part of the patient regarding the changes in lifestyle or the lack thereof in relation to his hearing impairment. For children, the testing for the effectiveness of the aids takes a different form since it cannot be expected that they have developed the same levels of awareness regarding their condition. The tests therefore include performance in daily living, especially academic and social development. In these stages of development, speech is a very important and a very good tool to help in the diagnosis, especially since it is necessary to hear sounds for communication to be able to develop among this population. In terms of the quality of life, children are also unable to verbalize satisfaction with aids, as precisely perhaps as adults. Measures to test the interventions therefore are different, and studies have used intelligence quotients, and other tests for communication in order to help them identify the efficacy of the interventions, and to be able to identify any gaps in the management of the children with hearing impairment. A study done by Sujata Satapathy noted that “…Academic performance has been considered as an interactive function of many psychosocial and demographic variables.” He studied students from the levels VIII and X, ranging from 13-21 years old form different demographic backgrounds. He compared these 80 hearing-impaired students with about 111 nonhearing-impaired students, and found that social adjustment was not very much different between the two groups, and both groups were noted to have improved in this area. Self-esteem did not, however, end up being very significant. He also noted though, that socio-demographic data may have a correlation to the academic-performance of the hearing-impaired students. The study took into consideration specific socio-demographic data and examined the differences on selected psychosocial (stress, self-esteem and socialemotional adjustment) and demographic variables and their correlations with academic performance of the hearing-impaired and non-impaired adolescents (Satapathy, 2007). He found out that contrary to most beliefs, the hearing-impaired group resulted in quite a well-adjusted group in terms of social-emotional adjustment as adolescents. The study showed that these hearing-impaired adolescents were better adjusted due to many factors noted by the author during the course of his study. These children had been provided a good social environment from pre-school up to the present, with social interactions between students and their teachers were very detailed in terms of helping the child develop skills necessary for communication, with emphasis on their interactions with other students. This resulted in well-adjusted families and adolescents who managed to handle the same stressors as their nonhearing-impaired counterparts with the same social-emotional and self-esteem levels (Satapathy, 2007). There was also note of a more or less good academic performance among this study group, which, as the author noted, was encouraging since it defies the misconception that any impairment would result in maladjusted adolescents. In this regard, it was shown by the author that although deaf people had an additional stressor in their families, it is also a fact that makes the support system stronger, especially in schools for the deaf where the teachers are very keen on helping their students adjust to their condition by helping them build ways of communication that need a lot of interaction. The author Satapathy also concluded that “…the finding of better academic performance of hearing impaired students could be interpreted by using the individualistic theory, which proposed that normal surroundings tend to compound the inferiority feelings in hearing-impaired persons which makes them try hard to develop and strengthen the compensatory mechanisms to achieve superiority (exhibited in better academic performance)…” (Satapathy, 2007). This may hold true for the group that was studied which had a good support system not just at home, but also in their schools, and who were diagnosed and managed earlier, and who were able to learn the different communication skills needed for a well-adjusted learning and communication necessary for social interaction in the community. Another study, this time a review of about the studies that have been done for the last few years on hearing impaired populations that have almost always concluded that the hearing impaired population had lower Intelligence Quotients than their hearing counterparts. This was done by McCay Vernon, which reviewed a total of 50 studies, and the author concluded that “…the series of studies which examined the relationship of the etiology of deafness to intelligence and the changes in etiology growing out of medical advances in treatment offer possible explanations of the disproportionateness of low IQs… based on these studies and on an understanding of the disease conditions that cause deafness, it is apparent that many etiologies for profound hearing loss are also responsible for other neurological impairment, which frequently result in lower intelligence…” (Vernon, 2005). With the advent of medical research and new technologies, he has summed up his findings and concluded that these diagnosed cases of hearing impaired individuals, when not affected mentally by the said condition that had caused the deafness in the first place are actually as intelligent and can do just as well as their hearing counterparts, and that such conclusions as had been made in the previous studies had been biased and did not take into account the concomitance of the deafness with neurologic conditions that can result in mentally retarded individuals included in the study. With these studies, we can see that hearing impairment is a common, albeit relatively treatable cause of disability in many countries. There is a need also for more support for studies in order to deal with those places where the diagnosis of hearing impairment is not being done routinely due to unavailability of resources for research, and if diagnosed, the concomitant unavailability of the technology for intervention. Many studies still need to be done regarding the other factors that may contribute to the state of the hearing-impaired population, and with the advent of genetics, interventions may be done earlier and with the use of more appropriate and patient- specific technology. Regarding the diseases that cause the impairment of the auditory system, they can now be prevented by screening, and even immunizations for those that are vaccine preventable like infections. Congenital hearing impairment resulting from maternal exposures and diseases are included in this aspect. It would also be an improvement if these interventions were made available even for third world populations where until now, no studies and no data are available, and even in the first world nations where screening is still not complete for the newborn, and the elderly. Provisions like screening for noise levels in industrial plants, and other work places have also been studied. Studies are lacking on other aspects of the quality of life that may be improved with the acknowledgment of society that these hearing impaired individuals are not in need of a different kind of attention, but only timely intervention, and proper social-emotional support for a good adjustment to the condition to occur. Further studies have also shown that psychological development of adolescents can be equivalent to their counterparts once intervention is started early, thus, as mentioned, the benefits of screening of infants. The follow-up of those who are screened is also necessary to improve the statistics of successful intervention and management. Some study designs need to be expanded also, as some authors have admitted that the limitations of their studies have included only those who have already received intervention, but may have benefitted from other, more appropriate treatments, as with those who had been using older types of hearing aids when they could already benefit from newer technologies, as with those who are in the elderly population. REFERENCES: 1. Polley, Sherry. Hearing Loss More prevalent Among Adults: Earlier Screening Recommended. ENT Today, November 2010. 2. Gaffney, M. et.,al. Newborn Hearing Screening and Follow-up: Are Children Receiving Recommended Services. Public Health Reports / March–April 2010 / Volume 125 (pages 199 – 207) From (www.publichealthreports.org/archives/issuecontents.cfm?Volume=125&Issue=2) 3. Probst, R. et. al.,Hearing Disorders in Children—Pediatric Audiology. From Basic Otorhinolaryngology: A step-by-step Guide. Pages 198-199. Georg Thieme Verlag. Thieme New York, New York USA. 2006. 4. Maclay, J. et.,al. MRI Reveals Inner Ear Anomalies in Children with Hearing Loss. From the Archives of Otolaryngology--Head & Neck Surgery. JAMA, 2008. Accessed on November 27, 2010. http://www.physorg.com/news140712590.html 5. Anonymous, "Study examines prevalence of hearing loss in the US." PHYSorg.com. 28 Jul 2008. Accessed on November 27, 2010. http://www.physorg.com/news136482724.html 6. Corna, et. al., Transitions in hearing impairment and psychological distress in older adults. Canadian Journal of Psychiatry, August 2009. 7. Beteljewski, S. Age connected hearing disorders (presbyacusis) as a social problem. Otolaryngology Pol., 2006. 8. Li-Mei Lin,et., al.. Deafness: Speech in Noise and Directional Hearing Effects with Bone-Anchored Hearing and Contralateral Routing of Signal Amplification. From Otology & Neurotology, 2006. 9. Akeem Olawale Lasisi. Age-related hearing loss and folate in theelderly.From Otolaryngology and Head and Neck Surgery. December 2010. Physorg.com. Accessed on November 26, 2010. http://www.physorg.com/news/2010-12-age-related-loss-folate-elderly.html> 10. Veras, R., et. al., Audiology and Aging: literature review and current horizons. Brazilian Journal Of Otorhinolaryngology, January/February 2007. Accessed on November 30, 2010. http://www.rborl.org.br / e-mail: revista@aborlccf.org.br 11. Vernon, M., Fifty Years of Research on the Intelligence of Deaf and Hard-of-Hearing Children: A Review of Literature and Discussion of Implications. Accessed on: November 30, 2010. Read More