• Educational Technology International
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• v.18 no.1
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• pp.49-71
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• 2017

The purpose of the study was to identify key design features of virtual reality with head-mounted displays (HMD) and touchless interface for the hearing-impaired and hard-of-hearing learners. The virtual reality based training program was aimed to help hearing-impaired learners in machine operating learning, which requires spatial understanding to operate. We developed an immersive virtual learning environment prototype with an HMD (Oculus Rift) and a touchless natural user interface (Leap Motion) to identify the key design features required to enhance virtual reality for the hearing-impaired and hard-of-hearing learners. Two usability tests of the prototype were conducted, which revealed that several features in the system need revision and that the technology presents an enormous potential to help hearing-impaired learners by providing realistic and immersive learning experiences. After the usability tests of hearing-impaired students' exploring the 3D virtual space, interviews were conducted, which also established that further revision of the system is needed, which would take into account the learners' physical as well as cognitive characteristics.

• Speech Sciences
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• v.8 no.4
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• pp.109-118
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• 2001

This study was designed to evaluate the phonological characteristics in profound hearing-impaired children. 10 males and 10 females participated in this study and all were prelingually hearing impaired. 7 children were educated at deaf school and 13 children at general elementary school with private clinic. Their hearing levels were more than 95dB HL and did not appear any wave by ABR. The results can be summarized as following: The articulation accuracy of hearing impaired children was 54.19% and most distinguished phonological patterns of the hearing impaired children were alveolarization and stop assimilation. The accurate articulation phonation was significantly different from education system between deaf school and general school. The error articulation degrees in profound hearing impaired children at general school seemed meaningfully smaller than those in hearing impaired children at deaf school.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.229-238
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• 2010

This study investigates the differences in acoustic parameters in vowel space across hearing loss, gender and vowels. The parameters include F1, F2, Euclidean Distance between vowels, and vowel triangular area comprised of /i/, /a/ and /u/. For this study, 20 hearing-impaired and normal hearing adults as a control group were asked to read 7 Korean vowels (/a, $\wedge$, o, u, w, i, $\varepsilon$/). Subjects' readings were recorded by NasalView and analyzed by Praat. Results showed that F1 were significantly higher in the hearing impaired group than in the normal hearing group, higher in the female group than in male group, and higher in low vowels than in high vowels. And the means of F2 was significantly higher in the hearing impaired group than in normal hearing group, higher in high vowels than in low vowels, and there was no difference between male and female group. Secondly, Euclidean distance between vowels was significantly shorter in the hearing-impaired group than in the normal group. Finally, acoustic vowel space area was significantly smaller in the hearing-impaired group than in the normal hearing group. The hearing-impaired group showed that front vowels tended to be backed and back vowels to be fronted.

• Phonetics and Speech Sciences
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• v.1 no.4
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• pp.177-185
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• 2009

This study investigates the differences in mean F0, intensity, jitter and shimmer across hearing aid, gender and vowels. 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 means of F0 were significantly higher in the hearing impaired group(HL) than in the normal hearing group(NH), in the female group than in male group, and in high vowels than in low vowels. Second, intensity was significantly higher in the normal hearing group(NH) than in the hearing impaired group(HL), in male group than in female group, and in low vowels than in high vowels. Third, jitter was significantly higher in the normal hearing group(NH) than in the hearing impaired group(HL), and in female group than in male group and in the back vowels than in front vowels. Finally, shimmer was significantly higher in the normal hearing group(NH) than in the hearing impaired group(HL), and in male group than in female group. In particular, the male group showed that front vowels tend to have higher shimmer than back vowels.

• Phonetics and Speech Sciences
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• v.2 no.1
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• pp.135-145
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• 2010

This study investigates the differences in mean F0, intensity, jitter, and shimmer across hearing aid, gender, and vowels. For this study, 18 hearing-impaired children, 18 cochlear implanted children, and 18 normal hearing children as a control group were asked to read seven Korean vowels (/$\alpha$, $\wedge$, o, u, w, i, $\varepsilon$/). Subjects' readings were recorded by NasalView and analyzed by Praat. Results showed that the means of F0 were significantly higher in the hearing impaired group than in the normal hearing group; in the female group than in the male group; and in high vowels than in low vowels. Second, intensity was significantly higher in the hearing impaired group than in the normal hearing group; in the female group than in the male group; and in low vowels than in high vowels. Third, jitter was significantly higher in the normal hearing group than in the hearing impaired group; in the female group than in the male group; and in back vowels than in front vowels. Finally, shimmer was significantly higher in the CI group than in the normal hearing group or the hearing aided group; in the male group than in the female group; and in low vowels than in high vowels.

• The Journal of the Acoustical Society of Korea
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• v.14 no.2
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• pp.113-122
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• 1995

This paper describes characteristics of a bone conduction telephone which was developed for conductive hearing impaired persons to call without additional devices and results of its performance test. Not only the hearing impaired but also normal hearing persons can use this telephone because we developed a bone conduction vibrator with which they can perceive speech signal using functions of air conductive hearing as well as bone conductive hearing. It also has tone control function compensating hearing losses for the hearing impaired originating from their hearing characteristics, and using this function together with received volume control it has received volume range of 20dB in loudness rating, which is similar effect as what a telephone set with built-in received amplifier has. From results of articulation and intelligibility tests for 19 hearing impaired persons, we can see that if their bone-conduction hearing loss is 61dB or less, they can understand words or sentences and response well with this telephone.

• 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 Korea Multimedia Society
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• v.3 no.5
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• pp.495-505
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• 2000

In this paper, we propose an efficient auto-fitting system for digital hearing-aids which automatically adjusts the fitting parameters according to the auditory characteristics of hearing handicapped person. The fitting parameters are extracted from audiogram of hearing handicapped and are applied to digital hearing-aid purposed GM3036 chip. The characteristics of each parameter are compared with those from theoretical 2cc graph. The purposed system has applied to 50 patients and their satisfaction ratios show to the very high. As results, it shows effectiveness of proposed system.

• Journal of Korea Multimedia Society
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• v.10 no.2
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• pp.200-208
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• 2007

The noise induced hearing loss, which is one type of the hearing losses, is well known occupational diseases. The prevention of the noise induced hearing loss is very important, because it is unrecoverable. There are some kinds of devices for hearing protection, and those are effective in preventing the noise induced hearing loss. However, people often resist the use of hearing protection devices because they have some difficulties during conversation in wearing the devices. To solve the problem, a small acoustic filter can be used for a hearing protection device. In this paper, we designed several kinds of small acoustic filters and analyzed the characteristics of designed small acoustic filters using Finite Element Analysis (FEA). From FEA results, we proved the characteristics of designed small acoustic filters which vary according to length and diameter. And we found out that the general tendencies of modeled filters using FEA are same as acoustic experiment results of designed filters.

• Journal of the Korean Society of Safety
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• v.28 no.4
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• pp.103-106
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• 2013

During a military service, noise has unusual characteristics, and constitutes a serious hazard to hearing of military servicemen. The purpose of this study is to understand the use of hearing protection and to assess the safety effects of hearing protection by using a ear plug in military. A total of 208(the army : 101, an air force : 107) serviceman were studied utilizing a questionnaire to know how many serviceman use the hearing protection and a total of 202(the army : 110, an air force : 92) serviceman were also studied using a ear fit validation device to assess the safety effects of hearing protection by using a ear plug. The results showed that the army have low used of hearing protection than an air force because of the low frequency of the noise exposure in the army. Personal attenuation rate was increased with 8 dB after fitting education. Therefore, it is recommended that use of proper hearing protection and fitting education was more suitable for military servicemen who were being exposed of the noise in domestic military.