• 스마트미디어저널
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• 제7권3호
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• pp.29-34
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• 2018

본 논문은 주변 소음이 많은 환경에서 보청기 수신 성능 향상을 위하여 적외선을 이용한 광통신 기술을 접목시키는 연구이다. 마이크로폰과 적외선 발광 다이오드를 포함하는 송신 모듈에서 음성신호를 적외선 광 신호로 변환시켜 공기 중에 내보내고, 일정 거리 떨어진 곳에 위치한 수신 모듈에서 적외선 신호를 수신하여 전기 신호로 변환하여 디지털 보청기의 입력 단에 전달한다. 특별히 수신 모듈은 보청기에 부착되어야 하므로 소형이며 저전압이고 저전력 소모가 바람직하다. 디지털 변조 방식과 아날로그 무변조 방식의 적외선 통신 기술을 적용하여 실험한 결과 실내에서 약 5미터 거리의 적외선 통신은 아날로그 무변조 방식이 적합함을 보였다. 송신 모듈과 수신 모듈 시제품을 제작하여 디지털 보청기에 연결하고 내부 파라미터를 조정하여 음성 신호를 정상 송수신함을 확인하였다.

• Journal of Audiology & Otology
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• 제25권1호
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• pp.8-13
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• 2021

Background and Objectives: In 2013, the Singapore government reviewed and expanded the Senior Mobility Fund (SMF) to provide subsidy for assistive devices, including hearing aids (HA). While SMF has improved accessibility to HA, its impact on HA acquisition has not been determined. The study aims to elucidate the influence of SMF on HA acquisition and the relationship between financial funding and compliance to HA use. Subjects and Methods: Retrospective review of 643 patients seen between January 2017 to January 2018 at the earnose and throat specialist outpatient clinic, who were referred for a hearing aid evaluation. Of the 643 patients, 109 patients with baseline hearing handicap (HH) scores recorded, and no formal diagnosis of cognitive impairment were included. The patients were grouped according to SMF eligibility and clinical data were obtained. Results: The odds ratio for acquiring HA was significantly higher with SMF, regardless of HH scores. When looking at actual degree of hearing loss (DHL), HA uptake was significantly higher in the least severe of DHL categories. There is no relationship between SMF and compliance to HA use. However, HH score is positively correlated with data log in regression analyses. Conclusions: SMF appears to influence HA acquisition. Especially in financially funded patients with low self-perceived HH, the benefits of HA may be underappreciated given the few hours of HA use. Further studies are warranted to investigate the impact of financial funding on outcomes of HA users to help policy planners and clinicians be prudent in the utilization of SMF.

• 대한청각학회지
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• 제25권1호
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• pp.8-13
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• 2021

Background and Objectives: In 2013, the Singapore government reviewed and expanded the Senior Mobility Fund (SMF) to provide subsidy for assistive devices, including hearing aids (HA). While SMF has improved accessibility to HA, its impact on HA acquisition has not been determined. The study aims to elucidate the influence of SMF on HA acquisition and the relationship between financial funding and compliance to HA use. Subjects and Methods: Retrospective review of 643 patients seen between January 2017 to January 2018 at the earnose and throat specialist outpatient clinic, who were referred for a hearing aid evaluation. Of the 643 patients, 109 patients with baseline hearing handicap (HH) scores recorded, and no formal diagnosis of cognitive impairment were included. The patients were grouped according to SMF eligibility and clinical data were obtained. Results: The odds ratio for acquiring HA was significantly higher with SMF, regardless of HH scores. When looking at actual degree of hearing loss (DHL), HA uptake was significantly higher in the least severe of DHL categories. There is no relationship between SMF and compliance to HA use. However, HH score is positively correlated with data log in regression analyses. Conclusions: SMF appears to influence HA acquisition. Especially in financially funded patients with low self-perceived HH, the benefits of HA may be underappreciated given the few hours of HA use. Further studies are warranted to investigate the impact of financial funding on outcomes of HA users to help policy planners and clinicians be prudent in the utilization of SMF.

• 한국멀티미디어학회논문지
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• 제3권5호
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• pp.495-505
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• 2000

본 논문에서는 난청환자의 청각손실로부터 디지털 보청기의 보정 파라미터를 자동적으로 추출하는 방법을 제안하고 이를 이용한 자동보정시스템을 구현한다. 디지털 보청기의 보정 파라미터는 난청환자의 청각 특성 오디오그램으로부터 자동으로 추출하였으며, 추출된 보정 파라미터는 실제 GM3036 디지털 보청기를 이용하여 보정 시스템으로 구현되었으며, 각 파라미터는 이론적인 2cc 출력에 근접하도록 테이블화 하였다. 제안한 자동 보정 시스템을 적용하여 검사기로부터 출력을 검증하였고, 50명에게 사용하게 한후 만족돌르 조사한 결과 자동 보정 시스템의 유효성을 확인할 수 있었다.

• 디지털산업정보학회논문지
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• 제8권2호
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• pp.49-58
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• 2012

This paper is on an improved orthogonal projection method which can cancel the acoustic feedback signals in the digital hearing aids. Comparing with the NLMS algorithm which is widely used for simplicity and stability, it shows that this method has the improvement of the convergence performances, and has small computational quantities, for signals with the large auto-correlation as speech signals. This uses the improved orthogonal projection algorithm which reduces the correlation of signals. To verify the convergence characteristics of the proposed algorithm, we simulated about various input signals. The acoustic feedback canceller has a 12-bit resolution with 64-tap adaptive FIR filter. And we compared the results of simulation for this algorithm with the ones for the NLMS algorithm. By these works, it is proved that the feedback canceller adopting the proposed algorithm shows about 3.5dB more high SNR than the NLMS algorithm in the colored input signals.

• 재활복지공학회논문지
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• 제11권2호
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• pp.143-146
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• 2017

본 논문에서는 recurrent neural network (RNN)을 이용하여 보청기 시스템을 위한 기존의 3GPP enhanced voice services (EVS) 코덱의 음성/음악 분류 성능을 향상시키는 방법을 제시한다. 구체적으로, EVS의 음성/음악 분류 알고리즘에서 사용된 특징벡터만을 사용하여 효과적으로 RNN을 구성한 분류기법을 제시한다. 다양한 음악장르 및 잡음 환경에 대해 시스템의 성능을 평가한 결과 RNN을 이용하였을 때 기존의 EVS의 방법보다 우수한 음성/음악 분류 성능을 보였다.

• 대한의용생체공학회:의공학회지
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• 제17권3호
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• pp.347-354
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• 1996

This paper presents digital hearing aids signal processing system in WT(wavelet transform) domain. For implementation of hearing aids in WT domain, the gain in frequency domain is approximated in WT domain. We also present the gain selection algorithm to deal with the change of input signal power. Most transform methods produce blocking effect, and this effect degrades the convergence rate of feedback canceller. As a solution, we proposed wavelet transform bascd feedback canceller. To evaluate the performance, we compared it with LOT (lapped orthogonal transform) method in the frequency domain. This system has not shown the blocking effect, and improves convergence rate as compared with the LOT based feedback canceller.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.248-251
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• 1996

In this paper, we presented WT(wavelet transform) domain feedback canceller in hearing aids system. Most transform methods produce blocking effect and this effect degrades the performance of feedback canceller and overall hearing aids system. As a solution we proposed WT based feedback canceller. The performance of this new approach was compared with LOT (lapped orthogonal transform) based method in the frequency domain. As a result, WT based feedback canceller has not shown the blocking effect and improved convergence rate as compared with the LOT based feedback canceller.

• Clinical and Experimental Otorhinolaryngology
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• 제11권4호
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• pp.250-258
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• 2018

Objectives. To compare narrative skills between fourth and fifth grades of Persian-speaking students with hearing impairments and typical hearing students of the same grade and also to evaluate the effects of group, sex, hearing age, and educational grade of the students on their spoken/written narrative performance. Methods. The subjects were 174 students aged 10-13 years, 54 of whom wore cochlear implants, 60 suffered from moderate to severe hearing losses and wore hearing aids, with the remaining 60 students being typical hearing in terms of the sense of hearing. The micro- and macrostructure components of spoken and written narrative were elicited from a pictorial story (The Playful Little Elephant) and then scored by raters. Results. Compared to the typical hearing, the students with hearing impairments had significantly lower scores in all of the microstructure components of narratives. However, the findings showed no significant difference among different groups in macrostructure components of narratives. It was also revealed that the students had equal performance in spoken and written narrative. Finally, factor analysis manifested that group, sex, hearing age, and educational level of children might alter the outcome measures in various interactions. Conclusion. Although cochlear implantation was more effective than hearing aid on spoken and written narrative skills, the Persian-speaking students with hearing impairments were seen to need additional trainings on microstructure components of spoken/written narrative.

• 전기학회논문지
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• 제62권12호
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• pp.1744-1749
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• 2013

Acoustic feedback is perceived as whistling or howling, which is a major complaint of hearing-aids users. Acoustic feedback cancellation is important in hearing-aids because acoustic feedback degrades performance of the hearing aid device by reducing maximum insertion gain. Adaptive systems for estimate acoustic feedback path and feedback suppression algorithms have been proposed in order to solve this problem. A typical feedback cancellation algorithm is LMS(least mean squares) because of its computational efficiency. However it has problem of convergence performance in high correlated input signal. In this paper, we propose a new variable step-size normalized LMS(least mean squares) algorithm using VAD(voice activity detection) to overcome the limitation of the LMS algorithm. The VAD algorithm is GSAP(global speech absence probability) and the feedback cancellation algorithm is normalized LMS. The proposed algorithm applies different step-size between voice and non-voice using VAD, for high stability, fast convergence speed and low misalignment when correlated inputs, such as speech. The result of simulation with white noise mixed speech signal, the proposed algorithm shows high performance then traditional algorithm in terms of stability, convergence speed and misalignment.