• The Journal of the Acoustical Society of Korea
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• v.41 no.1
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• pp.99-107
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• 2022

This study attempted to analyze the consonant perception ability and errors and to verify compatibility items for hearing impaired children wearing hearing aids and cochlear implants using the Phoneme Perception Test for School-Aged children (PPT-S). As a result of the study, it was found that children with hearing impairments have more difficulty in perceiving final consonants than initial consonants. The hard type of PPT-S, in which the articulation method and articulation place of the target and foil words are similar, felt more difficult than the easy type. Among the initial consonants, the incorrect response rate for aspiration sound was higher. In the case of final consonants, the incorrect answer rate for 'ㄷ' and 'ㅁ' was relatively higher. There was no significant difference in the percentage of correct response rate according to the gender of the speaker. The above results can be usefully used as basic data for standardizing of PPT-S and evaluating the intervention effects before and after hearing rehabilitation with hearing impaired children.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.21-28
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• 2007

In most of hearing aids, amplification algorithms are used to compensate hearing loss, noise and feedback reduction algorithms are used and to increase the perception of speeches contrast enhancement algorithms are used. However, acoustic masking effect is occurred between formants if contrast is enhanced excessively. To confirm the masking effect in speeches, the experiment are composed of 6 tests; test pure tone test, speech reception test, word recognition test, pure tone masking test, formant pure tone masking test and speech masking test, and for objective evaluation, LLR is introduced. As a result of normal hearing subjects and hearing impaired subjects, more making is occurred in hearing impaired subjects than normal hearing subjects when using pure tone, and in the speech masking test, speech reception is also lower in hearing impaired subjects than in normal hearing subjects. This means that acoustic masking effect rather than distortion influences speech perception. So it is required to check the characteristics of masking effect before wearing a hearing aid and to apply this characteristics to fitting curve.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.1
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• pp.67-72
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• 2013

Data from Panel Survey of Employment for the Disabled(4th year, 187 workers) was used for analyzing the difference between hearing aid users and nonusers for their job satisfaction and daily life satisfaction. The analyses result shows that there are no significant differences in both job satisfaction and daily life satisfaction between hearing aid users and nonusers. However, job satisfaction of hearing aid users has a positive role in daily life satisfaction. Although hearing aids to the hearing impaired played very important role, it was thought to be resulted that some influence factors such as the increase of using IT devices and the expansion of communication support services weren't applied because of the nature of the panel data. These limitations of the study and implications are presented at the conclusion.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.27-34
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• 2009

Hearing impaired person's hearing loss has personally various shape, so existing symmetrical auditory filter of frequency band method wasn't properly simulated the hearing impaired person's various hearing loss shape. The shapes of auditory filter are asymmetrical different with each center frequency and each input level. Hearing impaired person which has hearing loss was differently changed with that of normal hearing people and it has different value for speech of quality through auditory filter. In this study, the asymmetrical auditory filter was simulated and then some tests to estimate the filter's performance objectively were performed. The experiment as simulated auditory filter's performance evaluation method used perceptual evaluation of speech quality (PESQ) and log likelihood ratio (LLR) for speech through auditory filter. In the test, processed speech was evaluated objective speech quality and distortion using PESQ and LLR value. When hearing loss processed, PESQ and LLR value have big difference between symmetrical and asymmetrical auditory filter. It means that the difference of the shape auditory filter may affect to speech quality. Especially, when hearing loss existed, auditory filter changing according to asymmetrical shape for each center frequency affected to perceive speech quality of the hearing impaired.

• Speech Sciences
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• v.4 no.2
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• pp.103-113
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• 1998

The human baby appears to be born with preexistent knowledge of language. This specialized neural structure in the brain awaits auditory experience with language to trigger it into functioning. The auditory-linked acquisition of language is a time-locked function related to early maturational periods in the infant's life. The longer auditory language stimulation is delayed, the less efficient the language facility will be. It is for these reasons that it is urgent to fight the hearing problems of children with all the skill, knowledge and insights of which we are capable, the so called 'rehabilitative process'. An understanding of the timetable and the origin of prenatal to early life development of auditory mechanism will help in planning the aural rehabilitation. Further interests and studies are needed to establish the systematic structure of rehabilitative audiology.

• Journal of Audiology & Otology
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• v.25 no.2
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• pp.72-79
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• 2021

Background and Objectives: The speech-in-noise test is typically performed using an audiometer. The results of the digit-in-noise recognition (DIN) test may be influenced by the flat frequency response of free-field audiometry and frequency of the hearing aid fit based on fitting rationale. This study aims to investigate the DIN test in unaided and aided conditions. Subjects and Methods: Thirty four adults with moderate and severe sensorineural hearing loss (SNHL) participated in the study. The signal-to-noise ratio (SNR) for 50% of the DIN test was obtained in the following two conditions: 1) the unaided condition, performed using an audiometer in a free field; and 2) aided condition, performed using a hearing aid with an unvented individual earmold that was fitted based on NAL-NL2. Results: There was a statistically significant elevation in the mean SNR for the severe SNHL group in both test conditions when compared with that of the moderate SNHL group. In both groups, the SNR for the aided condition was significantly lower than that of the unaided condition. Conclusions: Speech recognition in hearing-impaired patients can be realized by fitting hearing aids based on evidence-based fitting rationale rather than by measuring it using free-field audiometry measurement that is utilized in a routine clinic setup.

• Speech Sciences
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• v.12 no.4
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• pp.197-202
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• 2005

The cochlear implantation(CI) as an useful tool for aural rehabilitation in bilateral severe to profound hearing impairment. However, CI prefer to usually one ear in spite of bilateral hearing impaired. because of the various characteristics of hearing loss, the hearing conservation for the future possibility, and socioeconomic condition of hearing impaired person and their families. The unilateral CI has limitations such as a directional loss, a difficult speech understanding in noise and a neural plasticity. These limitations will be overcome by hearing aid(HA) which is familiar with hearing impairer. but HA fitting for bimodal-binaural hearing are difficult because the difference output characteristic of HA and CI. This study will be confirm realities of use of HA in unilateral cochlear implantee. For this goal, 25(m:f=10:15) child participated who are used to HA for 1 to 17 months. We had telephone interviews with their mother about use of HA, change of auditory performance and own voice. As the results, hearing threshold levels of unimplanted ear, the use of a appropriate HA, implanted and aided hearing threshold level(HTL) are must be considered for successful biomodal-binaural hearing. Especially, implanted and aided HTL should be very useful parameter for a prediction of HA effect and a criterion of selection for bilateral cochlear implantation.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.2
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• pp.121-128
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• 2015

In this paper, we introduce our smart phone application for hearing impaired people. Unlike previous hearing aids application, our application has both functions of self hearing tests and sound amplification. We provide user with two types of self hearing test, those are standard hearing test and detail hearing test. Each test has different advantages like short test time and accurate test result, however both tests provide reliable result. Our hearing test allows that user can measure their hearing loss level according to the frequency. Sound amplification function provide proper fitting formula by using NAL-NL1, and it guarantees high speech intelligibility. Our application can also memorize user's fitting data at specific test condition. Therefore those who using our hearing aids application can easily reset their hearing aids / earphone properties periodically. Our application is advanced at the aspect of self fitting function that no other previous application did. So we are expecting these comfortable processes about fitting lead the number of hearing aids user to be increased.

• Journal of Korean Academy of Medicine & Therapy Science
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• v.10 no.2
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• pp.39-45
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• 2018

Objective: The aimes of this study is to analyze the effects of presbycusis on the quality of life. Method: 47-elderly were participated. The participants were divided into the suspected hearing impaired group (N=18) and the within normal limits (WNL) group (N=29). One-way ANOVA was performed to determine the association between the HHIE and WHOQOL-BREF scores by age group, and independent t-test was carried out to analyze the inter-group relations. Results: The scores in WHOQOL-BREF differed significantly by age group (p=.011): people in their sixties scored $3.7{\pm}.62$, those in their seventies $3.3{\pm}.56$, and those in their eighties $2.8{\pm}.60$, with significant differences observed. There were statistically significant inter-group differences (p=.000), with significant differences observed. Conclusion: The quality of life of the elderly were lowered depending on age and hearing impairment.

• Phonetics and Speech Sciences
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• v.6 no.2
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• pp.73-79
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• 2014

Alveolar fricative sounds /s/ and /s'/ are learned last for normal children in the speech development process for Koreans. These are especially difficult to articulate for hearing-impaired children often causing articulation errors. The acoustic phonetic evaluation uses testing tools to provide indirect and object information. These objective resources can be compared with standardized resources on speech when interpreting the results of a test. However, most previous studies in Korea did not consider acoustic studies that used the spectrum moment values of hearing-impaired children. Therefore, this study was conducted to compare the characteristics of hearing-impaired children's pronunciation of fricative sounds using spectrum moment values. For this purpose, the study selected a total of 10 hearing-impaired children (5 boys and 5 girls) currently in 3rd or 5th grade and attending one of the elementary schools in Seoul or Gyeonggi-do. For the selection process, their age, type of hearing aid, implantation of hearing aid (CI) before two years of age, hearing capacity (dB) before and after wearing the hearing aid, duration of speech rehabilitation, and time of learning alveolar fricative sounds were all considered. Also, 10 normal children (5 boys and 5 girls) were selected among 3rd or 5th grade students attending one of the elementary schools in Seoul or Gyeonggi-do. The subjects were asked to read the carrier sentence, "I say _______," including a list of 12 meaningless syllables composed of CV and VCV syllables, including alveolar fricative sounds /s/ and /s'/ and vowels /a/, /i/, and /u/. The recorded resources were processed through the Time-frequency Analysis Software Program to measure M1 (mean), M2 (variance), M3 (skewness), and M4 (kurtosis) of the fricative noise. No significant differences were found when comparing spectrum threshold values in the acoustic phonetic characteristics of hearing-impaired children and normal children in alveolar fricative sound pronunciation according to vowels /a/, /i/, and /u/, alveolar fricative sounds /s/ and /s'/, and syllable structure (CV, VCV) other than, for M3 in the comparison of groups according to disability. In the comparison of syllable structures, there were statistically significant differences in M1, M2, M3, and M4 with clinical significance. However, there was no significant difference in results when comparing the alveolar fricative sounds according to the vowels.