• The Journal of the Acoustical Society of Korea
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• v.26 no.1E
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• pp.8-13
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• 2007

It has long been known that high-frequency sensorineural hearing loss (HFHL) can contribute to difficulty in speech understanding by elderly listeners. This study evaluated the relative contribution of HFHL and age to speech understanding. Subjects included adult middle-aged and old groups with normal hearing or with limited HFHL. The Hearing-in-Noise-Test (HINT) was used to measure speech perception performance in quiet and in noise. The middle-aged groups showed significant effects of HFHL for speech intelligibility in quiet and in noise, but the old groups showed the difference in quiet only due to high frequency hearing. The results suggest that HFHL may affect speech intelligibility differently with age and therefore hearing aid selection needs to take into account the influence of age.

• Genomics & Informatics
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• v.16 no.4
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• pp.20.1-20.20
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• 2018

Genetic hearing loss crosses almost all the categories of hearing loss which includes the following: conductive, sensory, and neural; syndromic and nonsyndromic; congenital, progressive, and adult onset; high-frequency, low-frequency, or mixed frequency; mild or profound; and recessive, dominant, or sex-linked. Genes play a role in almost half of all cases of hearing loss but effective treatment options are very limited. Genetic hearing loss is considered to be extremely genetically heterogeneous. The advancements in genomics have been instrumental to the identification of more than 6,000 causative variants in more than 150 genes causing hearing loss. Identification of genes for hearing impairment provides an increased insight into the normal development and function of cells in the auditory system. These defective genes will ultimately be important therapeutic targets. However, the auditory system is extremely complex which requires tremendous advances in gene therapy including gene vectors, routes of administration, and therapeutic approaches. This review summarizes and discusses recent advances in elucidating the genomics of genetic hearing loss and technologies aimed at developing a gene therapy that may become a treatment option for in the near future.

• Korean Journal of Audiology
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• v.25 no.2
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• pp.80-88
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• 2021

Background and Objectives: Non-linear frequency compression (NLFC) technology compresses and shifts higher frequencies into a lower frequency area that has better residual hearing. Because consonants are uttered in the high-frequency area, NLFC could provide better speech understanding. The aim of this study was to investigate the clinical effectiveness of NLFC technology on the perception of speech and music in patients with high-frequency hearing loss. Subjects and Methods: Twelve participants with high-frequency hearing loss were tested in a counter-balanced order, and had two weeks of daily experience with NLFC set on/off prior to testing. Performance was repeatedly evaluated with consonant tests in quiet and noise environments, speech perception in noise, music perception and acceptableness of sound quality rating tasks. Additionally, two questionnaires (the Abbreviated Profile of Hearing Aid Benefit and the Korean version of the International Outcome Inventory-Hearing Aids) were administered. Results: Consonant and speech perception improved with hearing aids (NLFC on/off conditions), but there was no significant difference between NLFC on and off states. Music perception performances revealed no notable difference among unaided and NLFC on and off states. The benefits and satisfaction ratings between NLFC on and off conditions were also not significantly different, based on questionnaires, however great individual variability preferences were noted. Conclusions: Speech perception as well as music perception both in quiet and noise environments was similar between NLFC on and off states, indicating that real world benefits from NLFC technology may be limited in Korean adult hearing aid users.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.80-88
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• 2021

Background and Objectives: Non-linear frequency compression (NLFC) technology compresses and shifts higher frequencies into a lower frequency area that has better residual hearing. Because consonants are uttered in the high-frequency area, NLFC could provide better speech understanding. The aim of this study was to investigate the clinical effectiveness of NLFC technology on the perception of speech and music in patients with high-frequency hearing loss. Subjects and Methods: Twelve participants with high-frequency hearing loss were tested in a counter-balanced order, and had two weeks of daily experience with NLFC set on/off prior to testing. Performance was repeatedly evaluated with consonant tests in quiet and noise environments, speech perception in noise, music perception and acceptableness of sound quality rating tasks. Additionally, two questionnaires (the Abbreviated Profile of Hearing Aid Benefit and the Korean version of the International Outcome Inventory-Hearing Aids) were administered. Results: Consonant and speech perception improved with hearing aids (NLFC on/off conditions), but there was no significant difference between NLFC on and off states. Music perception performances revealed no notable difference among unaided and NLFC on and off states. The benefits and satisfaction ratings between NLFC on and off conditions were also not significantly different, based on questionnaires, however great individual variability preferences were noted. Conclusions: Speech perception as well as music perception both in quiet and noise environments was similar between NLFC on and off states, indicating that real world benefits from NLFC technology may be limited in Korean adult hearing aid users.

• Journal of Biomedical Engineering Research
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• v.30 no.2
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• pp.169-178
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• 2009

In this study, we suggest Korean nonlinear fitting formula (KNFF) to maximize speech intelligibility for digital hearing aids based on NAL-NL1 (NAL-nonlinear, version 1). KNFF was derived from the same procedure which is used for deriving NAL-NL1. KNFF consider the long-term average speech spectrum of Korean instead of English because the frequency characteristic of Korean is different from that of English. New insertion gains of KNFF were derived using the SII (speech intelligibility index) program provided by ANSI. In addition, the insertion gains were modified to maximize the intelligibility of high frequency words. To verify effect of the new fitting gain, we performed speech discrimination test (SDT) and preference test using the hearing loss simulator from NOISH. In the SDT, a word set as test material consists of 50 1-syllable word generally used in hearing clinic. As a result of the test, in case of moderate hearing loss with severe loss on high frequency, the SDT scores of KNFF was more improved about 3.2% than NAL-NLl and about 6% in case of the sever hearing loss. Finally we have obtained the result that it was the effective way to increase gain of mid-high frequency bands and to decrease gain of low frequency bands in order to maximize speech intelligibility of Korean.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.12 no.2
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• pp.140-144
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• 2001

Backgrounds & Objectives : Prolonged hearing loss was considered as one of the factors which have the potential to cause vocal changes. However, the analysis of quality of phonation in hearing loss patients has not been achieved enough. The purpose of the study was to evaluate the difference in objective acoustic parameters between long-term hearing impaired patients and normal control group. Material & Methods : The material of this investigation comprised a group of 20 patients (M : F=10 : 10) with moderate or profound hearing loss(over 50dB). The duration of all hearing loss was over 1 year. All of them underwent the acoustic examinations comprising electroglottography, multidimensional voice program and formant analysis during phonation of the bowels /a/ with free confortable tone and /i/ with voluntary high tone. The results of the acoustic examinations were compared with those of a control group, composed of 20 sex- and age-matched normal hearing subjects. Results : In the male hearing loss subjects, the significant increase was detected in pitch and shimmer during phonation of /a/ and in pitch during phonation of /i/. In addition, this group was characterized by decreased fundamental frequency during phonation of /i/. In female, there was no difference between hearing loss group and normal control group except a decreased formant 1 frequency. Conclusion : Long-term moderate and profound sensorineural hearing loss could affect the objective voice parameters.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.3
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• pp.138-144
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• 2017

In this paper, we propose a high frequency boosting circuits compensating for age-related hearing loss. The frequency response of this hearing loss is quite similar to that of a low-pass filter of which the critical frequency get lower with age. Therefore the voltage gain of this compensation circuits increase proportionally to the frequency of signals when the frequency is higher than the critical frequency and the voltage is constant irrespective of the frequency of signals when the frequency is lower than the critical frequency. The proposed circuits consist of a differential circuit and a unity gain amplifier. Because the critical frequency of the proposed circuits is controlled simply in the shape of a volume control lever, the aged people can adjust the high frequency boosting level easily according to one's hearing loss level. The critical frequency is continuously controllable in the whole audible frequency band and the gain of this high frequency boosting circuits is above 80dB at 10kHz.

• Speech Sciences
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• v.3
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• pp.50-56
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• 1998

Frequency transposition (FT) hearing system was designed for individuals with little or no residual hearing at high frequencies. This device compresses and shifts the wide-band, high frequency acoustic energy where important features for speech perception are concentrated to the audible, lower range of frequencies. The usefulness of the FT system was investigated for 12 patients (7 children and 5 adults) with severe-to-profound sensorineural hearing losses compared with conventional hearing aids. Results suggest that the hearing impaired can benefit from the FT system with appropriate selection criteria and auditory (re)habilitation program.

• The Journal of the Acoustical Society of Korea
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• v.29 no.3
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• pp.184-190
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• 2010

Lowering of auditory caused by noise is increased, these days. Especially, people who have noise induced hearing loss by permanent exposure to noise are increased according to spread out of multimedia and improvement of information equipment. The pure tone audiometry used in the hospital presently inspect auditory manually up to 8,000 Hz bandwidth. So the case of noise induced hearing loss which suffered from extended high frequency over 8,000 Hz, there is a problem to prevent hearing loss by precognition. In this paper, we proposed a method to prevent noise induced hearing loss by using extended high frequency bandwidth from 12,000 Hz to 20,000 Hz. We have got a experimental result to fifty of twenties who are often used to earphones through portable equipment. As a result, 36% of twenties show lowering of auditory caused by noise and 2% of them shows severe loss of hearing.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.33 no.3
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• pp.332-345
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• 2023

Objectives: We examined the association of hearing with cardio-metabolic diseases, dyslipidemia, hypertension and diabetes mellitus according to the personal and occupational characteristics of workers exposed to noise. Methods: The subjects of the study were 237,028 workers who underwent 2, 3, and 4 kHz airway pure tone audiometry in 2015 and who underwent clinical tests to diagnose cardiovascular-metabolic diseases. Cardiovascular-metabolic diseases were defined using reference values for respective items including blood pressure (systolic/diastolic), fasting blood glucose, cholesterol, and triglycerides. The airway pure tone hearing threshold of 2, 3, and 4 kHz, the average threshold of 2-3-4 kHz, and the hearing loss by the average threshold of the primary examination were distinguished. Results: Workers with cardiovascular-metabolic disease had significantly higher average hearing thresholds and higher rates of hearing loss. Logistic regression analysis, which adjusted for demographic variables of gender and age and occupational variables such as workplace size, industry, and type of work, and cardiovascular-metabolic disease as independent variables, showed that the odds ratio of hypertension to hearing loss in the mid-frequency was 1.239 (95% confidence interval: 1.118-1.374). For hypertension was 1.159 (1.107-1.214) and for diabetes it was 1.166 (1.104-1.230) for hearing loss in the high-frequency. Hearing loss measured by mean hearing was 1.178 (1.105-1.256) for hypertension and 1.181 (1.097-1.271) for diabetes. Conclusions: Cardiovascular-metabolic diseases in noise-exposed workers are associated with an increased risk of hearing loss and should be accompanied by bio-monitoring of cardiovascular-metabolic diseases in addition to auditory surveillance.