• Korean Journal of Audiology
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• v.23 no.1
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• pp.20-26
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• 2019

Background and Objectives: Autosomal recessive non-syndromic hearing loss (ARNSHL) with genetic origin is common (1/2000 births). ARNSHL can be associated with mutations in gap junction protein beta 2 (GJB2). To this end, this cohort investigation aimed to find the contribution of GJB2 gene mutations with the genotype-phenotype correlations in 45 ARNSHL cases in the Kurdish population. Subjects and Methods: Genomic DNA was extracted from a total of 45 ARNSHL families. The linkage analysis with 3 short tandem repeat markers linked to GJB2 was performed on 45 ARNSHL families. Only 9 of these families were linked to the DFNB1 locus. All the 45 families who took part were sequenced for confirmation linkage analysis (to perform a large project). Results: A total of three different mutations were determined. Two of which [c.35delG and c.-23+1G>A (IVS1+1G>A)] were previously reported but (c.299-300delAT) mutation was novel in the Kurdish population. The homozygous pathogenic mutations of GJB2 gene was observed in nine out of the 45 families (20%), also heterozygous genotype (c.35delG/N)+(c.-23+1G>A/c.-23+1G>A) were observed in 4/45 families (8.8%). The degree of hearing loss (HL) in patients with other mutations was less severe than patients with c.35delG homozygous mutation (p<0.001). Conclusions: Our data suggest that GJB2 mutations constitute 20% of the etiology of ARNSHL in Iran; moreover, the c.35delG mutation is the most common HL cause in the Kurdish population. Therefore, these mutations should be included in the molecular testing of HL in this population.

• Safety and Health at Work
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• v.12 no.2
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• pp.184-191
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• 2021

Background: Hearing protection devices (HPDs) are often used in the workplace to prevent hearing damage caused by noise. However, a factor that can lead to hearing loss in the workplace is improper HPD fitting, and the previous literature has shown that instructing workers on how to properly insert their HPDs can make a significant difference in the degree of attenuation. Methods: Two studies were completed on a total of 33 Hydro One workers. A FitCheck Solo field attenuation estimation system was used to measure the personal attenuation rating (PAR) before and after providing one-on-one fitting instructions. In addition, external ear canal diameters were measured, and a questionnaire with items related to frequency of use, confidence, and discomfort was administered. Results: Training led to an improvement in HPD attenuation, particularly for participants with poorer PARs before training. The questionnaire results indicated that much HPD discomfort is caused by heat, humidity, and communication difficulties. External ear canal asymmetry did not appear to significantly influence the measured PAR. Conclusion: In accordance with the previous literature, our studies suggest that one-on-one instruction is an effective training method for HPD use. Addressing discomfort issues from heat, humidity, and communication issues could help to improve the use of HPDs in the workplace. Further research into the effects of canal asymmetry on the PAR is needed.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.4-5
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• 1979

The degree of hearing impairment of chronic otitis media will indicate the nature and severity of middle ear pathology especially condition of ossicular chain, size of ear drum perforation and location of granulation tissue in the middle ear cavity. The subjects were 189 ears of tympanoplasty for chronic otitis media and divided into four groups as follows: Normal ossicular chain with only ear drum perforation (group I), normal ossicular chain with granulation tissue only around the ossicles regardless of any other region (group II), ossicular ankylosis or fixation of handle of malleus to promontory with or without granulation tissue around the ossicle (group III) and ossicular interruption by partial or complete destruction(groupf IV). The results were concluded as follows: 1) The average hearing threshold of chronic otitis media was 44.6 dB and hearing threshold was closely related to the condition of ossicular chain. Hearing threshold became greater in order of normal ossicular chain, ankylosis and interruption. 2) The average hearing threshold of ossicular interrupted group was 49.1 dB and it was greater in the cases of total destruction than that of partial destruction. 3) The hearing loss in the cases of normal ossicular chain with only tympanic membrane perforation was within 45 dB and this level was presumed to represent normal ossicular function. The degree of hearing loss was in proportion to the size of ear drum perforation and when over 45 dB, other middle ear pathology was suggested. 4) In the cases of small ear drum perforation with normal ossicular function, the hearing threshold was within 30 dB. 5) In the type of audiogram, flat type was 30.2% and ascending type 35.4%. Descending type was more frequent in the cases of normal ossicular mobility with granulation tissue around the ossicle and flat type was observed frequently in the cases of ossicular ankylosis. 6) Carhart's notch was seen in 14 cases (7.4%) and observed mainly in ossicular ankylosis. 7) There was no relation between hearing threshold and histopathological type of granulation tissue in chronic otitis media. However the degree of hearing impairment was related to the location of granulation tissue in the middle ear cavity. 8) Authors recognized the granulation tissue compensated the function of interrupted ossicular chain.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1978.06a
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• pp.9.2-9
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• 1978

Monaural and binaural hearing aid performance under quiet and noisy conditions were compared in regard to (1) the degree of hearing impairment, (2) the symmetry of pure tone audiogram, (3) the automatic gain control of the hearing aid. (4) hearing impairement with recruitment and, word discrimination ability. Performance using binaural hearing aids was consistently superior to that using monaural hearing aids. The results were as follows. 1. Speech detection thresholds were enhanced by a mean of 4.25dB when tested with danavox 747 PP stereo type hearing aid and by a mean of 4.12 dB when tested hearing aids connected seperately to the right and left ears. 2. Binaurally tested speech reception thresholds were superior to monaurally tested thresholds by a mean of 3.56dB when tested in quiet and by a mean of 5.56dB when tested in noise. 3. Binaurally tested word discrimination scores were also superior by a mean of 17.09% in quiet and by a mean 19.63% in noise. 4. Both SRT and word discrimination scores were performed best by subjects with moderately-severe impairement. The performance by one mildly impaired subject was the poorest of all performances. The levels of performance order were; moderately-severe loss, severe loss. moderate loss and mild loss. 5. The data obtained using AGC aids when compaired with that of linear amplification show that when AGC aids were worn in both ears. the results were very poor but when one AGC aid was worn in one ear and linear amplification in the other. the results were good. 6. The advantages of binaural hearing aids were obvious even in cases 1) with great diferences in hearing thresholds between right and left ears, 2) when the subject was unable to discriminate words without vision and. 3) when the subject had extreme recruitme t phenomenon.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.1
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• pp.19-40
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• 2017

A scientific and objective sound exposure criterion for underwater sound damage on fish has been required since there has been many disputes between an underwater sound maker and a fish damage receiver. The existing criteria are still incomplete scientifically owing to a degree of variability of underwater sounds, diversity of fish hearing sensitivity and damage types, etc. This study reviews existing studies on a hearing mechanism of fish species, manmade underwater sound characteristics and sound exposure assessment parameters, and recent sound exposure criteria. A governing equation for damage coverage estimation and damage coverage dependency on sound source level, ambient noise and transmission loss are also reviewed and interpreted based on sound exposure environments. The foreign and Korean (National Environmental Dispute Medication Commission) criteria are reviewed and compared based on scientific aspects. In addition, the deficit and limit of Korean criteria are presented. The objective of this study is to give a direction for related researches and legislation of sound exposure criteria on fish.

• Korean Journal of Audiology
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• v.25 no.3
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• pp.138-145
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• 2021

Background and Objectives: This study aimed to evaluate the audiologic results after cochlear implantation (CI) in older patients and the degree of improvement in their quality of life (QoL). Subjects and Methods: Patients over 65 years old who underwent CI at implant center in Bozyaka Training and Research Hospital were included in this study (n=54; 34 males and 20 females). The control group was patient over 65 years old with normal hearing (n=54; 34 males and 20 females). We administered three questionnaires [World Health Organization Quality of Life-BREF (WHOQOL-BREF), World Health Organization Quality of Life-OLD (WHOQOL-OLD)], and Geriatric Depression Scale (GDS) to evaluate the QoL, CIrelated effects on activities of daily life, and social activities in all the subjects. Moreover, correlations between speech recognition and the QoL scores were evaluated. The duration of implant use and comorbidities were also examined as potential factors affecting QoL. Results: The patients had remarkable improvements (the mean score of postoperative speech perception 75.7%) in speech perception after CI. The scores for the WHOQOL-OLD and WHOQOL-BREF questionnaire responses were similar in both the study and control groups, except those for a two subdomains (social relations and social participation). The patients with longer-term CI had higher scores than those with short-term CI use. In general, the changes in GDS scores were not significant (p<0.05). Conclusions: The treatment of hearing loss with CI conferred significant improvement in patient's QoL (p<0.01). The evaluation of QoL can provide multidimensional insights into a geriatric patient's progress and, therefore, should be considered by audiologists.

• Journal of Audiology & Otology
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• v.25 no.3
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• pp.138-145
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• 2021

Background and Objectives: This study aimed to evaluate the audiologic results after cochlear implantation (CI) in older patients and the degree of improvement in their quality of life (QoL). Subjects and Methods: Patients over 65 years old who underwent CI at implant center in Bozyaka Training and Research Hospital were included in this study (n=54; 34 males and 20 females). The control group was patient over 65 years old with normal hearing (n=54; 34 males and 20 females). We administered three questionnaires [World Health Organization Quality of Life-BREF (WHOQOL-BREF), World Health Organization Quality of Life-OLD (WHOQOL-OLD)], and Geriatric Depression Scale (GDS) to evaluate the QoL, CIrelated effects on activities of daily life, and social activities in all the subjects. Moreover, correlations between speech recognition and the QoL scores were evaluated. The duration of implant use and comorbidities were also examined as potential factors affecting QoL. Results: The patients had remarkable improvements (the mean score of postoperative speech perception 75.7%) in speech perception after CI. The scores for the WHOQOL-OLD and WHOQOL-BREF questionnaire responses were similar in both the study and control groups, except those for a two subdomains (social relations and social participation). The patients with longer-term CI had higher scores than those with short-term CI use. In general, the changes in GDS scores were not significant (p<0.05). Conclusions: The treatment of hearing loss with CI conferred significant improvement in patient's QoL (p<0.01). The evaluation of QoL can provide multidimensional insights into a geriatric patient's progress and, therefore, should be considered by audiologists.

• Journal of dental hygiene science
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• v.15 no.5
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• pp.603-611
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• 2015

This research is aimed at cutting off hearing loss and other harmful factors due to noise and providing basic material for noise reduction plan. As the research method, this research assessed noise by measuring acoustic pressure level and frequency in various situation of non-treatment and treatment. As the measurement result, average noise degree of high speed handpiece of non-treatment, ultrasonic waves scaler, and low speed handpiece showed 58~66 dB(A). Average noise degree of scaling of treatment, tooth elimination, and denture adjust showed 73~81 dB(A). The result is inferior to recognized standards of noise induced hearing loss. But the result of assessing this with (noise rating) NR curve was NR-73~78, which exceeded general workplace noise standard. This level can cause hearing loss when exposed to a long time. Therefore, treatment office noise during dental treatment can cause psychological and physical damage in dental clinic employees, and it is urgently required to establish systematic and active noise reduction plan.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.430-440
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• 2021

The purpose of this study was to analyze the degree of depression, cognitive function, communication ability, and the quantitative electroencephalogram (EEG) in elderly individuals with hearing loss and to investigate their inter-relationship. Hearing-impaired elderly participants, aged 60 years or older (37 men and 26 women) who visited the S Hearing Rehabilitation Center in Y City from June 20, 2020, to September 3, 2020, participated voluntarily after a recruitment announcement.The participants' overall characteristics, depression, and cognitive functions were evaluated with a structured questionnaire. The Word Recognition Score (WRS) was evaluated with an audiometer using the Korean Standard Monosyllabic Word Lists for Adults (KS-MWL-A). The quantitative EEG was measured with dry electrodes using a 2-channel EEG on the frontal lobes Fp1 and Fp2. The results are summarized as follows: Communication ability showed a positive correlation with the left-right symmetry of the frontal lobes (**p<.01) and a negative correlation with right-brain mental distraction and stress (*p<.05). In the difference WRS test for each group, the left-right symmetry of the frontal lobes (**p<.01) showed the greatest correlation with communication ability. Our results suggest that the left-right symmetry of the frontal lobes can be a biomarker indicative of the communication ability of older people with hearing impairments.

• Korean Journal of Social Welfare
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• v.66 no.3
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• pp.55-73
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• 2014

The purpose of this study was to develop and validate Korean version of Deaf Acculturation Scales(DAS). Pilot items were made a faithful translation of the Acculturation Scales of Maxwell-McCaw and Zea (2011) and were modified for Korean Deaf people. The Scale involves two dimensions, in order to measure the acculturation of Deaf people; Deaf acculturation and hearing acculturation. Using factor analysis, we developed a Korean version of DAS consisted of twenty-five items for Deaf acculturation dimension and twenty-five items for hearing acculturation dimension. These analysis supported the four factors of Deaf acculturation dimension and the five factors of hearing acculturation dimension. Reliability, assessed by Cronbach's ${\alpha}$, was .93 for Deaf acculturation and .93 for hearing acculturation, respectively, which confirm the Koran version of DAS. Construct validity was demonstrated through correlation with Deaf acculturation-related variables: age, age of Deafness, Degree of hearing loss, American Sign Language ability, and lip-reading ability. Criterion validity was supported by correlation with Collective Self-Esteem Scale. Limitation and implication of this study and direction for future research were discussed.