• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.1064-1069
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• 1994

In order to realize the function of human interface of telecommunications whose objective is to interchange useful information among persons, we developed a bone conduction telephone with which hearing impaired persons with conductive or noise-induced hearing loss and presbycusis can communicate with each other without any other additional devices such as hearing aids. The bone conduction telephone we developed has chatacteristics as follows : (i) a hearing impaired person and a normal hearing person can communicate by bone and air conduction hearings, respectively, using only this telephone set because, as its receiver, it uses a bone conduction vibrator with which we can realize such function with the voice coil and damper of a small speaker unit, the vibrating plate, etc., (ii) it has tone control function compensating hearing losses of hearing impaired persons according to their hearing loss/frequency chatacteristics. Using the tone control function together with a received volume control, it has the received volume range of 20dB in loudness rating; and (iii) it has the function of three emergency calls and a bell lamp as the visual display of a received call.

• 대한청각학회지
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• 제24권2호
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• pp.85-90
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• 2020

Background and Objectives: The present study aimed to compare thresholds of direct bone-conduction (BC direct) with those of behaviorally measured BC pure-tone audiometry (PTA) and objectively measured BC auditory brainstem response (ABR) to confirm the clinical feasibility of their relationships. Subjects and Methods: Young adults with normal hearing participated in the study to determine the thresholds from three measurements at four testing frequencies. In the BC direct, the vibrator of a bone-anchored hearing aid softband was placed on the right mastoid of each subject. In both PTA and ABR, a B71 bone oscillator was placed on the subject's right mastoid. While the subject's thresholds of BC direct and BC PTA were determined with a clinically routine 5-dB step procedure, BC ABR was conducted to determine the individual's hearing sensitivity by a peak V of the waveform using tone-burst and click stimuli. Results: The BC direct showed a different pattern between low and high frequencies. Precisely, its thresholds were 13.25 and 12.25 dB HL at 0.5 and 1 kHz, respectively, but 19 and 19.75 dB HL at 2 and 4 kHz, respectively. A significant positive correlation existed between BC direct and PTA at 1 kHz, which was also correlated with ABR. Conclusions: Based on the current data, the thresholds of BC direct were similar to BC PTA at low frequencies and BC ABR at high frequencies. The thresholds of BC direct might be predictable at approximately 5 dB higher (or lower) than that in PTA, although a large data set is required for standardization.

• Journal of Audiology & Otology
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• 제24권2호
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• pp.85-90
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• 2020

Background and Objectives: The present study aimed to compare thresholds of direct bone-conduction (BC direct) with those of behaviorally measured BC pure-tone audiometry (PTA) and objectively measured BC auditory brainstem response (ABR) to confirm the clinical feasibility of their relationships. Subjects and Methods: Young adults with normal hearing participated in the study to determine the thresholds from three measurements at four testing frequencies. In the BC direct, the vibrator of a bone-anchored hearing aid softband was placed on the right mastoid of each subject. In both PTA and ABR, a B71 bone oscillator was placed on the subject's right mastoid. While the subject's thresholds of BC direct and BC PTA were determined with a clinically routine 5-dB step procedure, BC ABR was conducted to determine the individual's hearing sensitivity by a peak V of the waveform using tone-burst and click stimuli. Results: The BC direct showed a different pattern between low and high frequencies. Precisely, its thresholds were 13.25 and 12.25 dB HL at 0.5 and 1 kHz, respectively, but 19 and 19.75 dB HL at 2 and 4 kHz, respectively. A significant positive correlation existed between BC direct and PTA at 1 kHz, which was also correlated with ABR. Conclusions: Based on the current data, the thresholds of BC direct were similar to BC PTA at low frequencies and BC ABR at high frequencies. The thresholds of BC direct might be predictable at approximately 5 dB higher (or lower) than that in PTA, although a large data set is required for standardization.

• International Journal of Internet, Broadcasting and Communication
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• 제8권4호
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• pp.48-53
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• 2016

Noise and vibration pollution is emerging to people in high speed trains. And it is difficult to realization of eco-friendly railway system at noise problem. The railway internal noise is 73dB on average and over 80dB in the loudest section. In order to reduce noise, there are passive methods that are far from noise sources and theother active noise reducion method. In this paper, we propose a method of reduce noise by measure and estimate the noise condition of train environment using Bone-Conduction device. We use an anti-phase waveform for canceling of noise characteristic. With this new system, the noise from surrounding environments can be reduced.

• Journal of Audiology & Otology
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• 제24권1호
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• pp.17-23
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• 2020

Background and Objectives: We aimed to measure the head dimensions on computed tomography (CT) images, to compare them to directly measured head dimensions, and to predict a new parameter of bone thickness for aiding bone conduction implant (BCI) placement. Subjects and Methods: We reviewed the facial and mandibular bone CT images of 406 patients. Their head sizes were analyzed using five parameters included in the 6th Size Korea project, and they were divided into age groups (ranging from the 10s to the 80s). We compared the head length, head width, sagittal arc, bitragion arc, and head circumference in the CT and Size Korea groups. We also added the parameter bone thickness for aiding BCI placement. Results: All the head size parameters measured using CT were significantly smaller than those measured directly, with head length showing the smallest difference at 7.85 mm. The differences in the other four parameters between the two groups according to patient age were not statistically significantly different. Bone thickness had the highest value of 4.89±0.93 mm in the 70s and the lowest value of 4.10±0.99 mm in the 10s. Bone thickness also significantly correlated with head width (p=0.038). Conclusions: Our findings suggested that the CT and direct measurements yielded consistent data. Moreover, CT enabled the measurement of bone sizes, including bone thickness, that are impossible to measure directly. CT measurements may complement direct measurements in the Size Korea data when used for developing bone conduction hearing devices (BCIs and headsets) for the Korean population.

• 대한청각학회지
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• 제24권1호
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• pp.17-23
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• 2020

Background and Objectives: We aimed to measure the head dimensions on computed tomography (CT) images, to compare them to directly measured head dimensions, and to predict a new parameter of bone thickness for aiding bone conduction implant (BCI) placement. Subjects and Methods: We reviewed the facial and mandibular bone CT images of 406 patients. Their head sizes were analyzed using five parameters included in the 6th Size Korea project, and they were divided into age groups (ranging from the 10s to the 80s). We compared the head length, head width, sagittal arc, bitragion arc, and head circumference in the CT and Size Korea groups. We also added the parameter bone thickness for aiding BCI placement. Results: All the head size parameters measured using CT were significantly smaller than those measured directly, with head length showing the smallest difference at 7.85 mm. The differences in the other four parameters between the two groups according to patient age were not statistically significantly different. Bone thickness had the highest value of 4.89±0.93 mm in the 70s and the lowest value of 4.10±0.99 mm in the 10s. Bone thickness also significantly correlated with head width (p=0.038). Conclusions: Our findings suggested that the CT and direct measurements yielded consistent data. Moreover, CT enabled the measurement of bone sizes, including bone thickness, that are impossible to measure directly. CT measurements may complement direct measurements in the Size Korea data when used for developing bone conduction hearing devices (BCIs and headsets) for the Korean population.

• 대한의용생체공학회:의공학회지
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• 제41권1호
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• pp.22-27
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• 2020

Auditory stimuli are commonly used in various electroencephalogram experiments, also in EEG-based brain-computer interface systems. However, using conventional earphones that blocks the ear canal attenuates or even blocks external environmental sound which might cause loss of crucial information from surroundings. Instead, bone-conductive earphones are able to deliver sound through vibration without blocking the ear canal. To investigate the feasibility of the bone-conductive earphones for auditory-stimuli based experiments, we compared N100 event-related potential features as well the event-related spectral perturbation and inter-trial coherence of auditory steady-state response between conventional and bone-conductive earphones. The results showed no significant differences between bone conduction and conventional earphones regardless of distinct sound pressures. This result shows that bone conductive earphones can be used for auditory experiments when the environmental sound is crucial to the user.

• 한국음향학회지
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• 제31권6호
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• pp.359-366
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• 2012

현대사회를 살아가는 사람들은 버스나 지하철과 같은 대중교통에서나 백화점이나 할인점 같은 다수의 사람이 모이는 환경에서 순전히 타의에 의해 온갖 소음에 노출된다. 이런 환경에서 휴대전화나 PMP 등 개인 휴대용 단말기 사용이 늘어나면서 공공장소에서 소음 문제는 점점 심각해지고 있다. 사람들은 소음환경 속에서 휴대기기를 이용해 원활한 정보교환을 위해 일반적으로 소음보다 15 dB이상 큰 음압으로 휴대기기를 구동하고 있다. 이러한 휴대기기의 음압을 측정해보면 110 dB까지 발생하고 있으며, 이렇게 발생한 음압은 사용자에게 소음성 난청을 유발시키고, 주변사람에게 또 다른 소음문제를 발생시킨다. 이러한 문제를 해결하기 위해 골전도 시스템을 이용한 방법을 제안한다. 본 논문에서는 휴대전화에 일반스피커와 함께 골전도 스피커와 골전도 마이크를 사용해 피드백을 통한 보상을 하였고, 이 방법에 의해 주변 소음의 영향을 줄이고 휴대전화 음질 향상하는 방법을 제안한다. 제안한 방법으로 휴대전화 사용자 주변의 소음에 대한 영향을 줄이고 통화 음질을 향상해 약 17 dB의 성능 향상효과를 확인하였다.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1979년도 제13차 학술대회 연제순서 및 초록
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• pp.3.2-3
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• 1979

만성중이염에서 나타나는 감각신경성난청은 고음역난청이며 이는 중이염의 흔하고 또 중요한 합병증이기도 하다. 자자들은 과거 1년간 경험한 233예의 만성중이염수술례중 187예를 대상으로 수술전 청력소견상 골도치에 대하여 임상소견을 중심으로 통계학적 분석을 하였으며 또한 기니픽의 자연발생한 만성화농성중이염의 병리조직학적소견을 관찰하여 보고하는 바이다. 대상의 평균연령은 24.5재이었다. 1) 일측성만성중이염에서 건측과 환측의 골도치를 이원배치산분석법으로 비교한 결과 건측과 환측간 및 각 주파수간에 유의한 차이가 있었으며 그들 사이에 유의한 상호작용이 인정되었다. 특히 2KHz와 4KHz 사이에서 유의한 차이(P<0.01)가 있었다. 2) 상병기간에 따른 일원배치분산 분석에서는 11∼15연군과 15∼20년군 사이를 제외한 각군간에서 유의한 차이(P<0.05)가 있었다. 3) 등골손상유무에 따른 분석에서 골도치를 t 검정으로 비교한 결과 각 주파수에서 모두 유의한 차이(p<0.01)가 있었으며, 등골손상의 주파수에 대한 영향을 일원배치분산분석법으로 비교한 결과 250Hz와 500Hz 사이 및 2KHz와 4KHz 사이에서 유의한 차이(P<0.05)가 있었다. 4) 정원창폐쇄유무에 따른 골도변화를 t 검정으로 비교한 결과 각 주파수에서 모두 유의한 차이(p<0.01)가 있었다. 정원창폐쇄의 각 주파수에 대한 효과를 일원배치분산분석법으로 비교한 결과 250Hz와 500Hz사이 및 2KHz와 4KHz사이에서 유의한 차이(P<0.01)가 있었다. 5) 진주종유무에 따른 골도변화를 t 검정으로 비교한 결과 진주종성중이염에서는 2KHz와 4KHz에서만 유의한 차이(p<0.01)를 보였으나 수도평균치에서는 유의한 차이를 보이지 않았다. 6) 기니픽의 만성화농성중이염의 측두골 병리조직학적 병변의 검경상 만성염증성병소의 내이, 특히 와우침입로로서의 정원창의 병변이 뚜렷하여 이로 인한 외임파강내의 염증성병변이 뚜렷이 나타나 있으며 와우관의 특히 기저회전에서의 유모세포의 손실이 심한 것으로 보아 중이염으로 인한 골도의 고음역에서의 손실이 발생함을 알 수 있다.

• Journal of Audiology & Otology
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• 제24권2호
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• pp.79-84
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• 2020

Background and Objectives: Hearing can be elicited in response to vibratory stimuli delivered to fluid in the external auditory meatus. To obtain a complete audiogram in subjects with normal hearing in response to pure tone vibratory stimuli delivered to fluid applied to the external meatus. Subjects and Methods: Pure tone vibratory stimuli in the audiometric range from 0.25 to 6.0 kHz were delivered to fluid applied to the external meatus of eight participants with normal hearing (15 dB or better) using a rod attached to a standard clinical bone vibrator. The fluid thresholds obtained were compared to the air conduction (AC), bone conduction (BC; mastoid), and soft tissue conduction (STC; neck) thresholds in the same subjects. Results: Fluid stimulation thresholds were obtained at every frequency in each subject. The fluid and STC (neck) audiograms sloped down at higher frequencies, while the AC and BC audiograms were flat. It is likely that the fluid stimulation audiograms did not involve AC mechanisms or even, possibly, osseous BC mechanisms. Conclusions: The thresholds elicited in response to the fluid in the meatus likely reflect a form of STC and may result from excitation of the inner ear by the vibrations induced in the fluid. The sloping fluid audiograms may reflect transmission pathways that are less effective at higher frequencies.