• 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.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.275-282
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• 2019

In airport terminal, aural information is transmitted during 24 hours a day including announcement, background music and emergency control. So, clear sound is mostly necessary to transmitted to the passengers in airports. IIA (Incheon International Airport) is one of the largest airports accommodating 45 million people a year which have been built since 2001. There are currently three passenger terminals including Terminal 1 & 2, and boarding concourse. The $2^{nd}$ passenger terminal is under construction to expand the spaces which will be finished in 2020. The present work aims to explain the design principles of both architectural acoustics and electo-acoustics which have been applied to all the terminal buildings in IIA including ticketing counter, great hall, departure concourse and transportation center. Also, the acoustical performances of those spaces were examined. As a result, acoustic standards for airport were suggested. Architectural concepts for designing ceiling spaces and sound absorption treatments were suggested. Also, electro-acoustic design principles were commented.

• The Journal of the Acoustical Society of Korea
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• v.24 no.7
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• pp.379-386
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• 2005

Among various kinds of hearing aids which have been developed so far. the conventional air conduction hearing aids have some problems such as the acoustic distortion, an howling effect due to acoustic feedback. Another type of hearing aid. the cochlear implant system can be applied to the profound imparied person. However. it shows the disadvantage that there is no possibility of recovery of the acoustic organ such as ossicle. On the other hand. the implantable middle ear heaving device directly vibratos the ossicular chain and has better sound qualify. good cosmetics for appearance. and wide frequency responses so that it can overcome the defects or the conventional hearing aids. In this paper, a mathematical modeling and a momentum equation derivation of the DET has been performed. For the optimization of the structure dimension generating maximal vibrating force of the DET. the computer simulation using a finite element analysis (FEA) software has been performed. Also. the vibrating transducer has been designed to make the frequency characteristics or the transducer be similar to those of the normal middle ear. Through the experimental results, the measured vibration characteristics of the DET has been evaluated to verify the performance for the application to implantable middle ear hearing devices.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.21 no.1
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• pp.42-47
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• 2010

Backgrounds and Objects: Carcinoma of the tongue is the most common cancer of the oral cavity. A primary treatment strategy includes surgery and/or radiotherapy. Resection of the tongue often results in speech dysfunction, which depends on the site and extent of resection, type of reconstruction, and the mobility of remaining tongue. This study aimed to evaluate the characteristics of articulation errors that were resulted from the partial glossectomy without free flap reconstruction. Materials & Method : Articulation evaluations including speech intelligibility and percent of correct consonants (PCC) were performed for 24 patients who underwent partial glossectomy for their T1 or T2 tongue cancer. Mobility of the tongue, size of the resected tongue, and the history of adjuvant radiotherapy were analyzed for their relationship with the results of articulation evaluation. Results: Speech intelligibility score was $6.4{\pm}0.9$ (on 7-point scale) and overall PCC was 96.9%. There were close relationships between the size of resection and limitations in the tongue mobility, especially in "protrusion and elevation (r=-0.687)" and "retroflexion (r=-0.775)". Errors in "alveolar fricatives" and "palatal affricates" were also closely related with the size of resection (r=-0.537 and -0.538, respectively). PCC for "liquid sound" /r/ was 83.2%, which was closely related with the history of radiation therapy. Conclusion : Overall articulatory function was satisfactory in cases of early tongue cancer after partial glossectomy of a limited volume without flap reconstruction. However, the size of resection and the history of radiation therapy were closely related to the limitations in some types of tongue mobility and the resultant articulation errors.

• The Journal of the Acoustical Society of Korea
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• v.35 no.2
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• pp.92-101
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• 2016

There are many results in which acoustical conditions of a classroom play an important role for studying effects and academic achievement of students. However, there are very few guidelines or design proposals which could make appropriate acoustic environment when classrooms are built or renovated. The present study suggests various design proposals satisfying acoustic standards of classrooms based on theoretical calculation and acoustic field experiments. At first, minimum area of sound absorption was calculated which is required to satisfy the acoustic standard for domestic middle and high schools. Also, room acoustic measurements were carried out in order to investigate the acoustic performance of an existing classroom by changing interior finishing materials on ceiling and rear walls. As a result, it was revealed that reverberation time standard below 0.8 s can be acquired even if there is no sound absorption on ceiling which is a general practice executed in Korea. Specially, it was found that if partial area of ceiling would be treated as reflective with the ratio of sound absorption and reflection as 2:1, almost similar acoustic parameters of $C_{50}$, $D_{50}$, RASTI (Rapid Speech Transmission Index) and higher sound levels could be acquired in comparison with the case of entire sound absorption on ceiling.

• Phonetics and Speech Sciences
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• v.5 no.2
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• pp.11-22
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• 2013

The purpose of this study was to identify the relationship between the strength of the tongue/lip strength and speech production for dysarthric adults with cerebral palsy. The maximal tongue and lip strengths of 22 normal adults, 27 dysarthric adults (10 adults with mild dysarthria, 10 adults with moderate dysarthria, and 7 adults with severe dysarthria) were measured with Iowa Oral Performance Instrument (IOPI). The percentage of correct consonants (PCC) and speech intelligibility were calculated from the words and sentences spoken by the subjects. The results of the study are as follows: First, both the maximal tongue and the maximal lip strength differed significantly between the control group and the group with dysarthria. While the group with mild dysarthria did not show meaningful difference in maximal tongue and lip strengths from the control group, the group with moderate and severe dysarthria showed significantly weaker tongue and lip strength than the control group and the group with mild dysarthria. Second, the current study suggests the existence of a significant correlation between the maximal tongue and lip strength and the PCC and speech intelligibility within all subjects with dysarthria. These findings can serve as an effective foundation to diagnose dysarthria quickly and accurately. The results of this study also indicate that in addition to the maximal tongue strength, the maximal lip strength can prove to be an important index in predicting the speech intelligibility of dysarthric adults with cerebral palsy.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.12
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• pp.1269-1280
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• 2009

This study was performed to construct sound performance DB of royal palace buildings and to examine the special quality more scientifically. Research target of royal palace were Changdeokgung and Gyeongbokgung. Sound insulation performance between the adjacent room and facade, room acoustics of Pyeonjeon and Chimjeon which is representative building in royal palace were examined through field measurement. Measured values of RT($T_{mf}$) at Pyeonjeon were 0.78 sec. and 1.03 sec. in Seonjeongjoen and Sajeongjoen, respectively. The RTs of both Pyeonjeon buildings were estimated suitable for speech and lecture considering their volume. The RT($T_{mf}$)s at Chimjeon were measured in range of 0.29~0.55 sec. This meant that the acoustic energy in rooms was decreased by sound transmission through mulberry paper(Hanji) of traditional windows and doors. As a sound insulation performance, the single-number quantities($D_{ls,2m,nT,w}$) of the building facades in Pyeonjeon and Chimjeon were measured 4~20 dB. Also the single-number quantities($D_{p,w}$) between the adjacent rooms in Chimjeon were measured 3~18 dB. Sound insulation performance of traditional building elements such as window and door depended strongly on their layers and area.

• The Journal of Sustainable Design and Educational Environment Research
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• v.19 no.2
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• pp.21-31
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• 2020

The purpose of this study was to analyze the contents of the sound environment among the various environmental factors that directly or indirectly affect the quality of education through the remodeling of the small hall of the College of Humanities at W University. Before remodeling into a lecture room, the small hall of the College of Humanities at W University, which is the subject of this study, was designed to create an indoor sound environment suitable for a lecture room by recognizing differences in acoustic performance between the performance halls that require adequate sound quality and the lecture rooms where the clarity of voice is important. Therefore, this study aimed to present examples of improved acoustic performance in lecture rooms by remodeling through the stages of measuring acoustic performance before remodeling, presentation of a change in finishing materials through sound simulation, and measurement of sound performance after remodeling. It is expected that this process can be used as an example of securing indoor acoustic performance suitable for educational space, such as lecture rooms, by changing the finishing materials.

• Phonetics and Speech Sciences
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• v.3 no.1
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• pp.125-134
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• 2011

The current study investigated the effects of experience of deaf speech, severity of speaker's articulation, and linguistic cues on speech intelligibility of congenitally deafened adults with cochlear implants. Speech intelligibility was judged by 28 experienced listeners and 40 inexperienced listeners using a word transcription task. A three-way (2 $\times$ 2 $\times$ 4) mixed design was used with the experience of deaf speech (experienced/inexperienced listener) as a between-subject factor, the severity of speaker's articulation (mild to moderate/moderate to severe), and linguistic cues (no/phonetic/semantic/combined) as within-subject factors. The dependent measure was the number of correctly transcribed words. Results revealed that three main effects were statistically significant. Experienced listeners showed better performance on the transcription than inexperienced listeners, and listeners were better in transcribing speakers who were mild to moderate than moderate to severe. There were significant differences in speech intelligibility among the four different types of cues, showing that the combined cues provided the greatest enhancement of the intelligibility scores (combined > semantic > phonological > no). Three two-way interactions were statistically significant, indicating that the type of cues and severity of speakers differentiated experienced listeners from inexperienced listeners. The current results suggested that the use of a combination of linguistic cues increased the speech intelligibility of congenitally deafened adults with cochlear implants, and the experience of deaf speech was critical especially in evaluating speech intelligibility of severe speakers compared to that of mild speakers.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1981.05a
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• pp.38.2-39
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• 1981

Speech reception threshold is a base for word discrimination testing, but it also serves as a check for the reliability of pure tone audiogram. In order to investigate the correlation between SRT and PTA these tests were carried out in patients with conductive hearing loss and normal hearing, using Grason-Stadler 1702 Audiometer. The results were as follows; 1) The difference between the scores of SRT and PTA's was 2.4 dB with a range of -3.3 dB∼+8.3 dB in conductive hearing loss, and was 1.9 dB with a range of -6.7 dB∼+5 dB in normal hearing group. 2) The difference between the scores of SRT and each speech frequency of PTA was 6 dB at 500 Hz, 3 dB at 1,000 Hz and 8.8 dB at 2,000 Hz in conductive hearing loss, and 3 dB at 500Hz, 2 dB at 1,000Hz, and 5dB at 2,000Hz in normal hearing group.