• Korean Journal of Audiology
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• v.23 no.2
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• pp.96-102
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• 2019

Background and Objectives: Temporal bone fracture (TBF) is a common occurrence in cases of head trauma. Although the incidence of temporal bone concussion (TBC) has increased in cases of head trauma, it has not been extensively studied. We assessed the characteristics of TBF and TBC in patients with head trauma. Subjects and Methods: We conducted a retrospective review of 432 patients with head injury who visited our hospital between January 2011 and April 2016. Of these patients, 211 who met the inclusion criteria were included in the study. Their clinical characteristics, causes of injury, and hearing function were analyzed. Results: Among the 211 patients, 157 had TBFs and 54 had TBCs. Ear symptoms were more common among patients with TBF than among those with TBC. Car accidents were the most common cause of both TBF and TBC, but assault and sports injuries were more common among patients with TBC than among those with TBF. The occurrence of facial palsy in both cases of TBF and TBC. Hearing loss was observed among 35 patients with TBF and 11 patients with TBC. However, patients with TBF showed conductive hearing loss with an air-bone gap. Hearing function of these patients with TBF recovered with a reduced air-bone gap, but the patients with TBC showed little recovery. Conclusions: Emergency physicians should focus more on temporal bone injury in patients with head trauma. Therefore, an early complete diagnostic battery, which includes high-resolution computed tomography, audiometric tests, neurologic examination, and vestibular tests, be performed in patients with head trauma.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.3 no.1
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• pp.21-25
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• 2009

Generally, fully implantable middle ear hearing device (F-IMEHD) is implanted under the skin nearby human temporal bone with all components including implantable microphone and vibration transducer. The microphone and transducer have different characteristic before and after implant. Fitting process is performed for this characteristic change of them and proper performance of hearing aids for each patient. Conventional hearing aids and partially implantable hearing aids, they have wired connector for fitting process. However in case of F-IMEHD, it is difficult this wired connection, because all components of F-IMEHD is implanted. In this paper, fitting software that can be apply wireless fitting hardware for F-IMEHD has been designed and implemented. It can find out proper fitting parameter reflecting characteristics of the microphone and transducer for patients who has difficulty in hearing.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.10 no.4
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• pp.273-278
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• 2016

Responded threshold level in hearing screening depends on the noise level of test surroundings, physiological characteristics of hearing organs, excessive sound source exposures, and so on. The purpose of this study is to obtain the basic information of hearing threshold level at each frequencies in children with passed hearing screening. Subjects were 110 children, aged were from 3.3 to 16.3 ($9.01{\pm}2.52$), who were at private speech language pathological clinics and daycare centers. Methods of Hearing screening were tympanometry, acoustic reflex threshold, automated otoacoustic emission, and pure tone screening. The subjects were in normal criteria of hearing screening. The differences of hearing threshold among ages and frequencies were measured by means of repeated measures ANOVA. The mean of hearing thresholds level was observed $16{\pm}6.49$, $11.5{\pm}4.79$, $6.86{\pm}4.99$, $5.95{\pm}6.65$ dB HL in the right ear and $15.68{\pm}6.01$, $9.95{\pm}5.24$, $5.72{\pm}5.21$, $5.63{\pm}7.04$ dB HL in the left ear, in frequency of 500, 1,000, 2,000, 4,000 Hz respectively. There was a significant difference between 500 and 1,000, 2,000, 4,000 Hz (p=.000), between 1,000 and 2,000, 4,000 Hz (p=.000).

• Journal of the Korean Society for Precision Engineering
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• v.26 no.12
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• pp.131-137
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• 2009

Recent technological advances made a vehicle more intelligent to increase safety and comfort. An intelligent vehicle provides drivers with safety warning information through audible sounds, visual displays, and tactile devices. However, elderly drivers have been known to decrease the physical and cognitive abilities such as muscular strength, hearing, eyesight, short term memory, and spatial perception. Therefore, possible age-related deficits should be considered to design an effective warning system. This paper aims to evaluate the impact of advancing age on response performance on audible safety warnings which are widely used for alerting driving hazards. In order to understand the effect of age-related hearing loss and movement slowing, three sound characteristics (frequency, intensity, and period) and three age groups (younger, middle, and older) are considered. Data was drawn from 38 drivers who drove a simulated rural road in a driving simulator. Experimental results show that age influences driver's response performance. In conclusion, the appropriate range of a warning sound is suggested.

• Journal of Korean society of Dental Hygiene
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• v.15 no.1
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• pp.11-17
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• 2015

Objectives: The purpose of the study is to investigate the relationship between noise awareness, hearing ability, and dental hygiene performance in dental hygienists. Methods: The subjects were 234 dental hygienists in Seoul, Gyeonggi-do, and Incheon. The questionnaire consisted of 3 questions of general characteristics of the subjects, 1 question of noise awareness, 3 questions of hearing ability, 5 questions of dental hygiene performance, 1 question of noise reduction necessity, and 2 questions of noise control. Noise awareness, dental hygiene performance, and noise reduction necessity were measured by Likert 5 scale. Cronbach's alpha was 0.825 in dental hygiene performance reliability. Results: There was a significant difference in noise recognition by age(p<0.01) and working career(p<0.05). Those who pumped up the higher TV volume accounted for 31.6% and 3.0% had hearing impairment in the regular health checkup. 3.4% of the respondents complained of hearing loss, ear fluid, and equilibrium problem diagnosed by the doctors. The relationship between the type of workplace environment and task performance showed a significant difference. Those who work in the dental hospitals had high score of 3.43, while those who work in dental clinics had 3.20(p<0.05). The increased level of noise recognition affected the task performance and it is necessary to reduce the noise level. More try must be focused on the noise exposure prevention. Conclusions: In order to reduce the problems due to noise and improve their quality of life, it is necessary to change the noise recognition in the work place.

• Journal of The Korean Association of Information Education
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• v.14 no.1
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• pp.1-12
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• 2010

For hearing-impaired students, it is known that reading ability is the most important means of communication. In the meanwhile, with recent development of wireless communication technologies, mobile devices are used in various education fields. The purpose of this study is to design and implement a mobile system to improve reading ability of hearing-impaired students. For this purpose, "Question Generation Strategy", known as one of the effective methods for improving reading ability, is adopted to make study contents. Also, 2Bi (Bilingual-Bicultural) Approach Model, an attractive model for improving reading ability of hearing-impaired students, is used. Characteristics of the proposed mobile system are as follows. First, the system is developed to let students learn written language usage through repetition and difference of two organically-related curriculums for hearing-impaired students. Second, study contents are made to increase sentence understanding ability using an activity that is to let students read articles, make questions and answer questions for themselves. Third, the proposed system is designed and implemented to allow students to choose study contents individually anytime anywhere depending on their study levels.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.1 no.1
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• pp.29-36
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• 2007

Recently, implantable middle ear hearing devices (IMEHDs) have been developed to overcome the problems of conventional hearing aids. In this paper, a piezoelectric floating mass transducer (PFMT) based on a PZT multi-layered actuator has been designed and implemented using the approximated mechanical vibration modeling for the PFMT and the analysis of vibration characteristics through the transformation into the equivalent electrical model. The implemented PFMT has been attached to the ossicle of a human cadaver's temporal bone and the in-vitro experiment has been performed. Through the experimental results, it has been verified that the PFMT applied into our developed implantable middle ear hearing device can be used for an IMEHD transducer.

• Proceedings of the KSPS conference
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• 2003.10a
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• pp.121-124
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• 2003

The purpose of this study was to show the characteristics of phonetic contrasts of one-syllable words and speech intelligibility in hearing-impaired adults. Seven subjects with hearing-impaired participated in this experiment(2 males, 5 females). The test materials are 77 pairs of one-syllable words with phonetic contrasts. The results of this study were as follows: (1) The average score of intelligibility(scored accuracy) was the highest in contrasts of onset feature. (2) The scored percentages of error(except for combinations of contrasts) were the highest in articulatory manner contrasts of onset, tongue height contrasts of nucleus, and articulatory place contrasts of coda, respectively.

• Biomedical Science Letters
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• v.22 no.4
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• pp.115-126
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• 2016

Audiometric calibration is a prerequisite for securing the reliability of audiometric test results by checking the internal consistency of the relevant instrument. The purpose of this review is to help instrument operators understand the calibration procedure of aural acoustic immittance instrument which is frequently used for objective assessment. By referring to the latest international standards and the national standards relevant to the aural acoustic immittance instrument, the following parameters will be reviewed: 1) introduction of performance characteristics, 2) detailed procedure of the calibration method. According to the newest international and national standards [IEC 60645-5 (2004), ANSI S3.39-1987 (R2012)], the aural acoustic immittance instrument basically includes six components: 1) calibration cavity, 2) acoustic immittance analysis system, 3) probe assembly/unit and signal, 4) pneumatic air-pressure pump system, 5) acoustic reflex activator system and 6) tympanogram and acoustic reflex plotting system, each of these components should meet set standards. The result of behavioral hearing tests is influenced by various complex factors including the examinee's cooperation, background noise of the examination room, measurement method, skill level of the audiologist and calibration status, but the objective hearing tests is more influenced by the calibration status of the instrument than any other factors. The audiologist should take full responsibility for the reliability of the hearing test result, so he/she should carry out the calibration check and adjustments of aural acoustic immittance instrument periodically and maintain the instrument continuously by referring to the newest standards and the manufacturer's instruction manual.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.529-534
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• 2009

One of the characteristics of the hearing impaired is that their frequency selectivity is poorer than that of the normal hearing. To compensate this, formant enhancement algorithms and spectral contrast enhancement algorithms have been developed. However in some cases, these algorithms fail to improve the frequency selectivity of the hearing impaired. One of the reasons is the acoustic masking among enhanced formants. In this study, we tried to enhance the formants based on the individual masking characteristic of each subject. The masking characteristic used in this study was minimum level difference (MLD) between the first formant to the second formant while acoustic masking was occurred. If the level difference between the two formants in each frame is larger than the MLD, the gain of the first formant was decreased to reduce the acoustic masking that occurred among formants. As a result of the speech discrimination test, using formant enhanced speeches, speech discrimination score (SDS) of the speeches having differently enhanced formants was significantly superior to SDS of the speeches having equally enhanced formants. It means that suppression of the acoustic masking among formants improve frequency selectivity of the hearing impaired.