• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.121-123
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• 1995

This paper presents a new method which compensates loss of loudness for digital hearing aids. Loudness grows more rapidly in frequency domain with substantial shifts of hearing threshold, so that loud sounds reach the uncomfortable sound level (UCL) at about the same physical stimulus level as with normal hearing. The result is a compression of the available dynamic range of hearing. Many techniques have been developed to compensate for hearing losses. In this paper, we propose a digital hearing aid which uses a single digital filter for reducing distortion and the fuzzy function to calculate gain factors. This function describes how much gain is needed for every frequency to restore loudness perception of a normal ear.

• Phonetics and Speech Sciences
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• v.1 no.3
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• pp.123-132
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• 2009

This study investigates the differences in nasalance across handicap, gender, and vowels and the correlation between nasal energy and oral energy both of which are used to compute nasalance. For this study, 20 hearing-impaired adults and 20 normal hearing adults as a control group were asked to read 7 Korean vowels (/$\alpha$, $\Lambda$, o, u, ɯ, i, $\varepsilon$/). Subjects' readings were recorded by NasalView and analyzed by Praat. Results showed that the hearing impaired group (HL) has a significantly higher nasalance than the normal hearing group(NH), and that there was a significant positive correlation between nasal energy and oral energy. A higher nasalance of the hearing impaired group seems to be due to an improper velopharyngeal control which is caused by lack of a proper auditory feedback.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.539-553
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• 1996

The study was conducted from May to September in 1994 to investigate applicability of the Hearing Handicap Inventory for the Elderly-Screening version(HHIE-S) in parallel with the pure-tone audiometer to the initial screening test of noise-induced hearing loss(NIHL) in some noise-exposed workers. Subjects were selected by systemic sampling that took every 10th person from 6, 700 workers taking the annual occupational health examination by the department of Health Maintenance of Dongsan Hospital Keimyung University in Taegu. The authors administered the pure-tone audiometric test and self-reported questionnaire of HHIE-S including items of sociodemographic and job-related variables concurrently. The final subjects analysed were 1,019(488 males and 531 females) excluding fourteen persons who had many missing values in their questionnaires. The reliability coefficients of HHIE-S scale by Cronbach's alpha were 0.84. In the univariate analysis of hearing handicap measured by the HHIE-S, work duration, military service and the hearing threshold loss at 1KHz and 4KHz by the initial audiometer were significant in males while age, work duration and hearing threshold loss at 1KHz and 4KHz were significant in females. In the stepwise linear regression analysis, hearing threshold loss at 1KHz and 4KHz, was the only selected variable explaining the hearing handicap in males and hearing threshold loss at 1KHz and 4KHz, age, and work duration were selected in females. In ROC curves for HHIE-S scores against NIHL as gold standard which was defined by the follow-up audiogram as more than 30dB of the average of 0.5/1/2KHz and 50dB at 4KHz, the optimal cutoff for the parallel HHIE-S appeared to be 8. The results suggest that HHIE-S appeared to have some reliability and validity in this data and might be used in screening NIHL in parallel with pure-tone audiometer in noise-exposed workers.

• Clinical and Experimental Pediatrics
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• v.49 no.8
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• pp.845-850
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• 2006

Purpose : To assess the incidence of neonatal hearing loss in a neonatal intensive care unit and the relative importance of risk factors for hearing imparement in a neonatal intensive care unit which the Joint Committee on Infant Hearing(JCIH) had recommended. Methods : One thousand, two hundred and one newborns admitted to the Good Moonhwa Intensive Care Unit from May 2003 to December 2005 were assesed using the automated auditory brainstem response(AABR). The screening was performed on those aged more than 36 weeks and weighing more than 2,200 g. We divided the infants into two groups, 'pass' and 'refer'. The 'refer' group were retested one month later, and if classified as 'refer' during the retest, were referred to a hearing impairment clinic. Results : From the 1,201 neonates, 1,187(98.8 percent) passed the test and 14(1.2 percent) failed. 293(24.4 percent) of the 1,201 neonates had a risk factor for hearing impairment; 282(96.2 percent) passed the test and 11(3.8 percent) failed. The group with risk factors were shown to have a higher incidence of hearing loss(P<0.001). The neonates in the refer group were shown to have a higher incidence of ototoxic drugs(P<0.001), low birth weight(<1,500 g)(P<0.001) and craniofacial anomalies(P=0.007). On the other hand, there were no statistical differences between the pass and refer groups in congenital infection, hyperbilirubinemia, bacterial meningitis, low Apgar scores, prolonged mechanical ventilation and syndromes known to include hearing loss. Conclusion : In order to identify hearing-impaired infants within an appropriate period, neonatal hearing screening tests and identification of the risk factors for neonatal hearing loss are important.

• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.87-98
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• 2022

The purpose of this study is to develop the Korean version of Music-Related Quality of Life (K-MRQoL) for the elderly. The K-MRQoL consisted of Musical Ability, Attitude, Activity Frequency (PART 1) and Musical Ability, Attitude, Activity Important (PART 2). Each subcategory consists of Music Perception with 11 items and Music Engagement with 7 items. The validity and reliability of K-MRQoL were measured with Pearson's and Cronbach's alpha correlation coefficients and Independent t-test in total 30 elderly with normal hearing and 30 elderly with hearing loss from local welfare Centers and nursing homes. The correlation coefficients between total scores and PART 1 and PART 2 ranged from .701 to .948 and from .598 to .926, respectively. The internal consistency between total and Part 1 and Part 2 ranged from .846 to .931 and from .838 to .918, respectively. The test-retest correlations were .979, .970, and 979 for total, PART 1, and PART 2, respectively. The correlation between K-MRQoL and Quality of Communication Life Scale was .449. There were significant differences in total, PART 1, and PART 2 between the elderly with normal hearing and hearing loss. This indicates that the K-MRQoL can be used as a useful clinical tool to evaluate Music-related Quality of Life in the elderly with normal hearing or hearing loss.

• Journal of Life Science
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• v.31 no.5
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• pp.453-463
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• 2021

Hearing loss is a group of clinically and genetically heterogeneous disorders characterized by congenital- to adult-onset deafness with frequent additional symptoms such as myopathy, nephropathy, and optic disorders. It is commonly divided into two types: syndromic, with no other symptoms, and nonsyndromic, with other symptoms. Autosomal recessive hearing loss is relatively frequent in Pakistan, which may be due in part to frequent consanguineous marriages. This study was performed by whole exome sequencing to determine the genetic causes in two Pakistani consanguineous families with autosomal recessive hearing loss. We identified a pathogenic homozygous variant (p.Leu326Gln in MYO7A) in a family with prelingual-onset hearing loss and two variants of uncertain significance (p.Val3094Ile in GPR98 and p.Asp56Gly in PLA2G6) in a family with early-onset hearing loss concurrent with muscular atrophy. The missense mutations in MYO7A and PLA2G6 were located in the highly conserved sites, and in silico analyses predicted pathogenicity, while the GPR98 mutation was located in the less conserved site, and most in silico analysis programs predicted its nonpathogenic effect. Homozygosity mapping showed that both alleles of the homozygous mutations identified in each family originated from a single founder; spread from this single source might be due to consanguineous marriages. This study will help provide exact molecular diagnosis and treatment for autosomal recessive hearing loss patients in Pakistan.

• The Journal of the Acoustical Society of Korea
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• v.30 no.4
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• pp.207-214
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• 2011

Human auditory acuity decreases naturally due to aging. But recently cases of impaired hearing at a young age are increasing greatly. The biggest reason for such an increase of population with impaired hearing is popularization of various kinds of portable multimedia appliances. Many studies on impaired hearing due to noises caused by the earphone and headphone are being made, but there are few studies on noise-impaired hearing caused directly by mobile phone communication. Based on a precedent inquiry, this study proposes a technique for preventing noise-impaired hearing applying to an active noise reduction technique onto bone conduction speaker. This technique is a method for reducing noises by antiphase oscillation through bone conduction speaker with ambient noises. If the proposed system is applied, the noise level that is actually introduced to audition decreases by more than 12 dB, and such a decreased amount of sound volume fundamentally prevents the factors of noise-caused hearing difficulty due to mobile phone communication. Sensibility test results showed that adequate communication was possible even in such a situation where communication volume was decreased like this.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.402-411
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• 2023

Background: We hypothesized that fatty liver disease (FLD) is associated with a high prevalence of hearing loss (HL) owing to metabolic disturbances. This study aimed to evaluate the association between FLD and HL in a large sample of the Korean population. Methods: We used a dataset of adults who underwent routine voluntary health checkups (n=21,316). Fatty liver index (FLI) was calculated using Bedogni's equation. The patients were divided into two groups: the non-FLD (NFLD) group (n=18,518, FLI <60) and the FLD group (n=2,798, FLI ≥60). Hearing thresholds were measured using an automatic audiometer. The average hearing threshold (AHT) was calculated as the pure-tone average at four frequencies (0.5, 1, 2, and 3 kHz). HL was defined as an AHT of >40 dB. Results: HL was observed in 1,370 (7.4%) and 238 patients (8.5%) in the NFLD and FLD groups, respectively (p=0.041). Compared with the NFLD group, the odds ratio for HL in the FLD group was 1.16 (p=0.040) and 1.46 (p<0.001) in univariate and multivariate logistic regression analyses, respectively. Linear regression analyses revealed that FLI was positively associated with AHT in both univariate and multivariate analyses. Analyses using a propensity score-matched cohort showed trends similar to those using the total cohort. Conclusion: FLD and FLI were associated with poor hearing thresholds and HL. Therefore, active monitoring of hearing impairment in patients with FLD may be helpful for early diagnosis and treatment of HL in the general population.

• Neonatal Medicine
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• v.16 no.2
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• pp.213-220
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• 2009

Purpose: Hearing loss is one of the common birth defects in humans, with a reported prevalence of 1-3 per 1000 newborns. We investigated the incidence of hearing loss and evaluated the use of neonatal hearing screening test in neonatal intensive care unit (NICU) graduates who are at greater risk for hearing loss than normal newborns. Methods: The neonates admitted to the NICU of Asan Medical Center from 1 March, 2003 to 30 March, 2008 who were available for follow-up were included. Those who failed the first auditory brainstem response prior to discharge were retested with the stapedial reflex test, auditory brainstem response and tympanometry in the Otolaryngology department. Results: Of 2,137 neonates, 2,000 (93.5%) neonates were tested prior to discharge. Sixty-seven neonates (3.4%) failed the first newborn hearing screening test. Of 67 infants, 52 infants were retested for a second hearing test. Excluding 10 infants (19.2%) who were lost during follow-up, 16 infants were confirmed to have hearing impairment of which 12 and 4 infants had unilateral and bilateral hearing loss, respectively. Of 16 infants, 5 did not meet the criteria set by the Korean National Health Insurance Corporation. Conclusion: The prevalence of hearing impairment in NICU graduates is about 0.8%, excluding those who were lost for follow up, necessitating a systemic and effective hearing assessment program among these high risk infants and more generous national insurance coverage.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.11 no.1
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• pp.73-79
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• 2017

It is difficult to detect the adult hearing loss after the language acquisition because of its slow progression, which can be evaluated voluntarily and actively when the appropriate tools are provided. Smartphones are one of useful tools, and they can utilize surveys and/or applications for hearing screening. This study aims to verify the possibility as a tool discovering delayed acquired hearing losses by comparing the pure tone screening application (app_PTS) which was recently developed by our research team and hearing handciap inventory (HHI). The subjects were 22 people whose age ranges from 10s to 80s. For pure tone averages (PTAs), hearing threshold level was selected the best one in same frequency, in both ears. Sensitivity and specificity of HHI were confirmed based on self awareness of hearing loss and PTAs at 1, 2, 4 kHz. Comparisons of two tests were measured by analyzing simple regression of correlation between PTAs of App_PTS and HHI scores. Sensitivity and specificity were 1.000 in both criteria. There was a statistically significant relationship between the PTAs_4 kHz and HHI (R-square = .951, p = .000). Hearing screening by questionnaire showed high correlation with smart phones based on application. Therefore, it can be useful as a hearing screening tool for individual life cycle using an user-friendly tool.