Noise thermometry using a broadband radio-frequency measurement at low temperatures

박정환 서울대학교 대학원 2012 국내박사

This thesis presents the development of the broadband radio-frequency noise measurement techniques at low temperatures. Especially, these techniques were used to realize noise thermometry using broadband noise measurement. The noise thermometer can be usable in the temperature range from 0.1 K to 300 K. A metallic tunnel junction which generates temperature-dependent thermal noise and voltage-dependent shot noise is used as a noise source. From thermal noise we can get information about the temperature of the electrons in the tunnel junction and the background noise level can be calculated using shot noise. Very small noise signal from the tunnel junction is amplified by a cryogenic low noise amplifier and then detected by Schottky diode detector which converts broadband noise power into the DC voltage. For a radio-frequency measurement at low temperatures we developed an experimental setup in cryogenic refrigeration systems like He4 probe, He3 cryostat, and dilution refrigerator. The system consists of two measurement chains. One of them, DC measurement chain, is used to apply currents and read the voltage across the tunnel junction. The other, RF measurement chain, is used to transmit RF signal from the tunnel junction to the diode detector. Because the thermal conductivity of most metals decreases with decreasing temperature, careful tuning of the RF and DC components is performed for sufficient cooling of the electron temperature. By developing the filtering processes for preventing the external RF noise from reaching the tunnel junction, the precision of the noise thermometer was increased. And with an imperfect tunnel junction we got the result that an inelastic tunneling process can make the electron temperature look higher. This result was analyzed by using numerical simulation. Finally, an experimental plan for the electron-phonon scattering rate using this measurement technique will be introduced. 이 논문은 저온에서의 광대역 무선주파수 잡음 측정기술 개발에 관해서 기술한다. 특히, 이 기술은 광대역 잡음측정을 이용한 잡음온도계 구현에 이용되었다. 잡음온도계는 0.1 K에서 300 K까지의 온도영역에서 사용이 가능하다. 온도 의존적인 열적잡음과 전압 의존적인 산탄잡음을 발생시키는 금속 터널접합이 잡음원으로 사용되었다. 열적잡음으로부터는 터널접합에 있는 전자들의 온도에 관한 정보를 얻을 수 있고, 배경잡음은 산탄잡음을 이용하여 계산될 수 있다. 터널접합으로부터 나오는 매우 작은 잡음신호는 저온 저잡음 증폭기에 의해 증폭된 후 쇼키 다이오드 디텍터를 통하여 DC 전압으로 변환된다. 저온에서의 무선주파수 측정을 위해서 He4 프로브와 He3 냉동기, 희석냉동기와 같은 극저온 냉장 시스템에 실험장치를 구성하였다. 이 시스템은 두 개의 측정체인으로 이루어져 있다. 터널접합으로 전류를 흘리고 전압을 읽을 수 있는 DC 측정 체인이 있고, 터널접합에서의 RF 신호를 다이오드 디텍터로 전송하는 RF 측정 체인이 있다. 대부분의 금속은 저온으로 갈수록 열전도도가 낮아지기 때문에, 전자온도의 충분한 냉각을 위해서 RF 와 DC 측정 체인에 사용되는 부품들을 신중하게 조율하였다. 외부 무선잡음이 터널접합으로 들어오는 것을 막기 위한 필터링 작업을 통해서 잡음온도계의 정밀도가 개선되었다. 그리고 불완전한 터널접합에서는 비탄성 터널링 현상이 전자의 온도를 높게 보이도록 만든다는 결과를 얻게 되었다. 이 결과는 수치 모사실험을 통하여서 분석하였다. 마지막으로, 이 측정기술을 이용한 전자-포논 산란비 실험 계획을 소개한다.

성인중환자실 간호사의 소음관리 수행도에 영향을 미치는 요인

김서정 경상국립대학교 대학원 2022 국내석사

The purpose of this study was to examine the relationships between nurses’ performance of noise management, noise experience, noise-related knowledge, response to noise, and patient safety culture and to identify factors affecting nurses’ performance of noise management in adult intensive care units. The subjects of this study were 148 nurse in adult intensive care unit with over 3 months of clinical experience working at advanced general hospitals in J and C cities. Data were collected from April 1st to 20th, 2022. The collected data were analyzed using frequency, percentage, mean, standard deviation, Independent t-test, one-way ANOVA, Scheffe's test, Pearson's correlation coefficient, and hierarchical multiple regression analysis by SPSS/WIN 25.0 program. The results of this study are summarized as follows. 1) The general characteristics of nurses in adult intensive care units were as follows. The nurses’ mean age was 28.36±4.29 years old and most of them was general nurses (96.6%). The mean years of nurses’ nursing experience was 5.52±4.34 years and the mean years of working experience in the intensive care unit was 4.23±2.30 years. Regarding noise-related characteristics, 35 nurses (23.6%) reported that the unit applied ‘quiet time’ and ‘quiet time’ was applied between midnight and 8 am. However, 113 nurses (76.4%) reported that the unit did not apply ‘quiet time.’ 147 nurses (99.3%) reported that they had no experience of receiving education on noise management. 112 nurses (75.5%) reported that the education on noise management is needed. 2) The mean score of noise experience frequency was 3.05±0.62 (range 1-4). The mean scores of its subcategories were: 3.41±0.62 of medical device factors, 2.99±0.63 of human factors, 2.96±0.84 of environmental factors. The mean score of perceived noise levels was 4.69±1.51 (range 0-10). The mean scores of its subcategories were: 5.93±1.84 of medical device factors, 4.50±1.51 of human factors, 4.05±1.90 of environmental factor. The total score of noise-related knowledge was 28.91±9.98 (range 0-54) and the percentage of correct answer was 54%, which was generally low. The mean score of response to noise was 4.89±2.32 (range 0-10). The mean scores of its subcategories were: 4.22±2.29 of physiological response and 5.42±2.55 of emotional response. The mean score of patient safety culture was 3.52±0.49 (range 1-5). The mean scores of its subcategories were: 3.86±0.66 of patient safety knowledge and attitude, 3.72±0.63 of teamwork, 3.62±0.71 of leadership, 3.53±0.72 of patient safety policy and procedure, 3.30 ±0.74 of patient safety improvement system, 3.26±0.83 of non-punitive environment, and 2.86±0.70 of patient safety priority. The mean score of performance of noise management performance was 3.45±0.64 (range 1-5). 3) There was a significant difference between the necessity of noise management education in nurses’ performance of noise management (t=2.66, p=.009). 4) There were significant positive relationships between nurses’ performance of noise management and noise experience frequency (r=.20, p=.013), noise-related knowledge (r=.21, p=.009), response to noise (r=.23, p=.005) as well as patient safety culture (r=.50, p<.001). 5) The factors affecting nurses’ performance of noise management in adult intensive care units were noise experience frequency (β=.16 p<.030), teamwork of patient safety culture (β=.33, p=.006) and patient safety policy and procedure of patient safety culture (β=.25, p=.037) explaining 37.9% of the variance. In conclusion, the factors affecting nurse’ performance of noise management in the adult intensive care unit were noise experience frequency, teamwork of patient safety culture, and patient safety policies and procedures of patient safety culture. Based on these results, we suggest that the a noise reduction intervention program should be developed using teamwork reinforcement and team approach to improve performance of noise management for nurses in adult intensive care units. Also, in addition to nurses’ personal efforts for noise management, organizational efforts and strategies are needed by establishing patient safety policies and procedures related to hospital noise at the hospital level.

High-Resolution and Energy-Efficient Bio-Potential Acquisition Systems based on Noise-Shaping SAR

Geunha Kim DGIST 2025 국내박사

軍用航空機 騷音被害 救濟에 관한 公法的 考察

김학선 경희대학교 대학원 2010 국내박사

The purpose of the thesis is to propose a new bill dealing with military aircraft noise and its remedy after analyzing judicial cases and their problems. Although, in view of private law system, legal remedies of aircraft noise have continuously been dealt with, several aspects such as difficulty of proving causation and broaden scope of damage consist of substantial burden of prove to plaintiff. Moreover, a claim for damage itself seems not to give a fundamental resolution on the aircraft noise issue because such a lawsuit merely functions as a remedy after it already occurred than preliminary protection, and the only plaintiff who sue for damage in the said case can receive a certain amount of money as compensation. In short, it is likely impossible for the private law and its remedy without considering public law’s aspect to perfectly handle and control the problem because it includes not only private rights and property issues but governmental protective issue on it. In this circumstance, considering the two aspects as before and after of aircraft noise problem at the same time, this paper focuses on the prospective protection and control of the noise and its damage by establishing a relevant special act. For this end, this paper, beginning with the basic question, “What is noise?”, consist of the followings. First of all, as a general study on aircraft noise, characteristic and effect of noise will be addressed. Under the Noise And Vibration Control Act, noise is defined as “strong sound resulting from using machine, device, facility and other objects” (Para. 1 of Art. 2), but in reality, unlike other pollution resources, noise gives rise to damage to the physical, mental, and social health due to its special nature of broaden scope affecting time and location. Especially, aircraft noise still infringes person’s property rights and its interest. In the situation, although the Korean government amended the Aviation Act and Enforcement Decree of the Aviation Act for the legal ground of noise prevention measures, current situations are just to follow court's decisions without noise surrounding standard, noise regulation standard, noise area/land use standard, and compensation criteria etc. Secondly, developed countries’ legislation and policy are reviewed based mainly on the case of Japan, the U.S., and Germany. particularly, in Germany, an integrated legislation simultaneously controls aircraft noise problems resulting from both civil airport and military airport. In Japan, as dealing separately and specifically with public airport, special purpose airport, civil airport and military airport, relevant legislations have been enacted to properly address noise prevention measures and its compensation policy. Thirdly, noise damage cases and their theory are studied focusing especially on the two material cases, Kimpo Airport Noise Damage Case(Supreme Court, 2005) and Maehyangri Case(Supreme Court, 2004). As for a damage theory under Korean legal system, the Constitution Law is generally based on unlawfulness, and the State Compensation Act also relies on illegality. Even though the behavior making noise in the process of military mission is legal under public law system, the supreme court, in Maehyangri Case, did not apply loss compensation theory, but apply endurance level theory which is general legal test on pollution claims. This paper, however, argues that the way compensated by establishing a special Act based on loss compensation theory would be proper. Finally, this paper looks through the legislative solutions in order to deal with aircraft noise issue as the public law aspect. After comparing with each other and analyzing the current two bills from the Ministry of National Defense and the Ministry of Land, Transport and Maritime Affairs, and each relevant lawmakers’ bills, this thesis proposed these two Ministries’ integrated bill. There are two reasons. One is, as to addressing aircraft noise suffering, there is no substantial difference between civil aircraft and military aircraft. The other is, if different law applies for between civil and military airports, it is likely to violate rights to equality under the Constitution Law. In conclusion, insisting on lack of budget, the government should not delay the relevant special Act. This is mainly because such a continuous delay will come back to it with the more suffering people and more damage. Additionally, the government should consider and build some substantive and effective compensation provisions which include noise damages, when enacting the Aircraft Noise Suffering and Its Remedy Act.

Noise and vibration analysis for wheel/rail interaction

김정훈 Graduate School, Korea University 2012 국내박사

According to increase of the interest about environmental problem nowadays, social requirements about environmental friendliness rapidly increase in the railway. Along with changes, these have increased such as the civil complaint, conflict and enforcement of environmental standard. However, the noise and vibration research in the railway is significantly inadequate in Korea. Therefore, development of the railway noise and vibration core technology is needed. Moreover, in recent years, a number of researches about the dynamic characteristics of the noise and vibration in the railway have been performed. As a result, as the high frequency vibration which occurs in the irregularity of the wheel and rail running surfaces causes the track noise in railway system, the noise and vibration analytic studies with measurement for the wheel and rail is needed. Theoretical models describing the interaction between the wheel and track are used for noise and vibration analysis. The high frequency vibration analysis model is as follows. An infinite homogeneous structure consisting of double beams continuously supported by elastic layers is a common model for this kind of track. The upper beam describes the rail, the lower one models the concrete slab, while the two elastic layers reflect the properties of the rail-pad and the track sub-grade. The wheel is modeled as two masses model. The contact spring stiffness (kH), damping (c1) and stiffness (k1) of the rail-pad among these wheel and track properties are particularly very important to dynamic analysis model. This Analysis Models that have been developed for wheel/rail noise and vibration are generally linear in order to make use of a frequency-domain approach. In fact, the local elasticity between the wheel and the rail exhibits a nonlinear stiffness behavior due to geometrical effects. Also, when most of the researches for the noise and vibration analysis of the wheel/rail interaction are performed, the hysteretic damping to reflect the damping coefficient is considered. However, characteristics of the hysteretic and viscous damping are a little different. Therefore, the noise and vibration analysis for the wheel/rail interaction using the nonlinear contact spring and viscous damping are performed and analyzed in this study. Using that developed program, analytical studies on the concrete slab and ballast track were performed and evaluated in this study. This is able to provide especially the analysis tool and technique for noise/vibration guidelines on the design. To obtain the same results between the analysis and measurement, the noise and vibration studies for the railway structure should be continuously for the further study

In vitro Modeling of Noise-Induced Hearing Loss using in vivo Data of Gene Expression Changes or Direct Noise Stimuli

하정호 아주대학교 일반대학원 2024 국내박사

마우스에서 aldosterone 전처치가 소음에 의한 내이손상에 미치는 영향

송형민 울산대학교 일반대학원 2007 국내석사

연구배경 및 목적: 소음성 내이손상에서 스테로이드의 보호효과에 대해서는 많은 연구가 있으나 대부분 glucocorticoid에 대한 보고이다. 하지만 와우에서 내림프의 항상성 유지에 관여하는 aldosterone이 소음성 외상에서 glucocorticoid와 동일한 보호효과를 갖는지에 대한 문헌 보고는 없다. 본 연구에서는 마우스에서 aldosterone이 소음에 의한 내이손상에 미치는 영향에 대해서 알아보고자 하였다. 대상 및 연구 방법: 청성 뇌간 유발 반응에서 25 dBHL 이하의 정상 청력을 보인 BALB/c 마우스를 실험에 사용하였다. 42마리의 마우스를 water군, prednisolone(PD)군, aldosterone(AD)군으로 구분하였고 청력의 영구역치변동과 일과성역치변동에 대한 aldosterone의 효과를 알기 위해 120 dB SPL의 광대역 백색잡음에 하루에 3시간씩 각각 3일군과 2일군으로 나누어 노출시켰다. 소음을 주기 전에 청성뇌간유발반응으로 청력역치를 먼저 측정한 후, 소음에 노출시킨 후 청력을 측정하여 청력감소를 확인하였다. 그 후 7일과 14일 뒤 다시 청력을 측정하여 소음 노출 후 청력의 변화를 확인하였다. 소음노출에 따른 혈청 aldosterone의 변화를 알아보기 위해 9마리의 마우스를 대상으로 상용 radioimmunoassay킷을 이용하여 혈청 aldosterone을 측정하였다. 결과: 소음에 노출된 마우스는 비노출군에 비해 혈청 aldosterone의 농도가 유의하게 감소하였다. 영구역치변동을 일으킨 마우스에서 PD군과 AD군은 대조군과 비교하여 청력보호 효과를 보이지 않았다. 또한 일과성역치변동을 일으킨 마우스에서 Water군, PD군, AD군은 투여약물에 따른 차이가 없이 소음노출 후 7일째 부분적인 청력의 호전을 보였고 소음노출 후 14일까지 더 이상의 청력의 호전은 없었다. 결론: BALB/c 마우스에서 소음노출 후 혈청 aldosterone의 유의한 감소가 관찰되었다. 하지만 aldosterone과 prednisolone의 전처치는 영구역치변동과 일과성역치변동을 일으킨 실험군 모두 대조군과 비교하여 소음성 내이손상에 대하여 보호효과가 없었다. Background and objectives : While the prevention of noise-induced hearing loss had been widely studied, the preventive effect of aldosterone on the noise trauma has not been documented to date. The study was designed to measure the serum aldosterone level after noise exposure and to determine the protective effects of aldosterone pretreatment on hearing in noise trauma. Materials and Method : BALB/c hybrid mice with 25 dB HL or less in ABR were used in this study. 42 mice were randomly assigned to one of several pretreatment drugs and divided into two day-exposure group (N=21) and three day-exposure group (N=12) according to the noise exposure time. All drugs were given in the drinking water, shown previously to be effective, daily from 4 days before noise exposure. The three day-exposure groups were: Water group (N=4), prednisolone (PD) group (N=4), and aldosterone (AD) group (N=4). The two day-treatment groups were: Water group (N=7), PD (N=7), AD group (N=7). Mice were exposed to 120 dB SPL broad white band noise for 3 hours per day for 2 days or 3 days. The preventive effects of PD and AD on noise trauma were determined by comparing the threshold shifts of auditory brainstem responses (ABR) before and after noise exposure and also 7 and 14 days following the exposure. The serum aldosterone level was measured in 3 mice without noise exposure and 6 mice with noise exposure. Result: The decrease of serum aldosterone level was seen in mice after noise exposure. The ABR threshold shifts were 80 dBHL or more in the three day-exposure groups. In Water, PD, AD groups of the two day-exposure groups, the threshold shifts were 70 dBHL or more noted after the noise exposure and some degree of hearing recovery was observed on the 7^(th) day after the exposure. But, ETOH, SP, PD+SP, AD+SP groups showed permanent threshold shift (PTS) on the 7^(th) day after the exposure. Conclusion: In BALB/c mice, the decrease of serum aldosterone level was seen after noise exposure. But pretreatment of aldosterone and prednisolone before noise exposure didn’t demonstrate the prevention of the elevated thresholds.

The Physiological and Neurological Study of Noise-Induced Hearing Loss in Mice : 마우스 모델을 이용한 소음성 난청의 전기생리학적·신경학적 분석에 관한 연구

이병현 경북대학교 대학원 2020 국내박사

Hearing loss is mostly due to genetic causes, and acquired hearing loss has become a social problem due to the increase in life expectancy at the turn of modern society and the increase in presbycusis and minor hearing loss due to the development of various industries. In particular, in the case of small deafness, the research on the developmental mechanism is deficient, and as a result, no effective therapeutic agent has been developed so far. In this study, I established a mouse animal model of noise-induced hearing loss, and investigated the physiological and neurological mechanisms of noise-induced hearing loss. Depending on the strength of the noise stimulus, white noise 100 dB for 2 hours, 4 hours, or 110 dB for 2 hours, 4 hours to establish a mouse model of temporary hearing loss and permanent hearing loss respectively. Auditory brainstem response was measured 2 hours after noise stimulation in exposed mouse models, and continuous monitoring at 1-week intervals in mice with confirmed hearing loss. It was confirmed that when the noise of 100dB was given for 2 hours, a temporary hearing loss was shown, and when the noise of 110 dB was given for 4 hours, the permanent small hearing loss was displayed. Morphological analysis of hair cells in the inner ear to determine the exact causative mechanism of hearing loss revealed that no direct hair cell damage had occurred. I analyzed the results measured by auditory brainstem response in detail, and predicted that changes in nerve cell activity appeared in response to noise stimulation. In order to investigate changes in nerve cells associated with hair cells, I confirmed the connection of hair cell ribbon synapses by immunofluorescence, and as a result, the connection of synapses was rapidly reduced by about 50% immediately after noise stimulation. On the other hand, after 3 weeks, the number of normal synapses was restored in the case of temporary hearing loss, while only about 10% was observed in the case of permanent hearing loss. This revealed that in the case of small deafness, the damage of nerve cells appears first rather than the direct damage of hair cells and the deafness is induced. Based on the results of this study, by explaining the mechanism by which minor deafness is displayed, the target is accurately presented for future research and development of therapeutic agents for noise-induced hearing loss. 난청은 대부분 유전적 원인에 의해서 나타나지만 현대사회로 접어들면서 평균수명 증가 및 다양한 산업 발전에 따른 노인성 난청과 소음성 난청의 증가에 따라 후천성 난청이 사회적 문제로 나타나고 있다. 특히, 소음성 난청의 경우에는 발생기작에 대한 연구가 미비하며 이에 따라 아직까지 효과적인 치료제의 개발이 이루어지지 않고 있는 실정이다. 본 연구에서는 이러한 소음성 난청을 연구하기 위한 기초가 되는 소음성 난청 마우스 동물모델을 확립하고 소음성 난청에 대한 생리적, 신경학적 기전에 대해 알아보고자 하였다. 소음자극의 강도에 따라 일시적인 소음성 난청과 영구적인 소음성 난청 마우스 모델을 각각 확립하기 위하여 백색소음 100dB 을 2시간, 4시간 또는 110dB을 2시간, 4시간을 각각 노출시킨 마우스모델을 소음자극 후 2시간 뒤 청성뇌간유발반응을 측정하여 소음성 난청이 확인된 마우스를 대상으로 1주일 간격으로 지속적인 모니터링을 통해 100dB 소음을 2시간 주었을 때 일시적인 소음성 난청을 나타내고 110dB 소음을 4시간 주었을 때 영구적인 소음성 난청이 나타나는 것을 확인 할 수 있었다. 정확한 난청 원인 기작을 알아보기 위해 내이의 유모세포의 형태학적 분석을 통해 유모세포의 직접적인 손상은 일어나지 않았다는 것을 알 수 있었다. 청성뇌간유발반응에 의해 측정된 결과를 심층 분석하여 소음자극에 따라 신경세포의 활성의 변화가 나타나는 것을 예측하였다. 이에 유모세포와 이와 연결된 신경세포의 변화를 알아보기 위해 유모세포의 리본시냅스의 연결을 면역형광법을 통해 확인 한 결과 소음자극 직후 시냅스의 연결이 50%가량 급격히 줄어든 반면 3주 뒤에는 일시적 소음성난청의 경우 정상적인 시냅스 수를 회복하는 반면 영구적 소음성 난청의 경우 10% 가량의 회복만 관찰되었다. 이를 통해 소음성 난청의 경우 유모세포의 직접적인 손상보다 신경세포의 손상이 일차적으로 나타나 난청이 유발 되고 있음을 밝힐 수 있었다. 본 연구 결과를 바탕으로 소음성 난청이 나타나는 기작을 설명함으로써 앞으로 진행될 소음성 난청 치료제 개발 연구에 타깃을 정확히 제시 해줌으로써 난청 극복에 큰 기여할 것으로 전망된다.

A Novel Noise Mitigation using Adjacent Pixel Values

성치혁 금오공과대학교 대학원 2017 국내석사

디지털 이미지나 비디오는 여러 가지 요인들로 인해 저장이나 전송 과정에서 잡음을 얻을 수 있다. 본 논문에서는 이러한 잡음을 완화할 수 있는 인접한 픽셀의 값들을 이용한 새로운 잡음 완화 기법을 제안한다. 잡음 환경으로는 Salt & Pepper Noise와 Additive White Gaussian Noise를 고려하였고, 각각 0이나 255의 픽셀 값 탐지와 Cyclic Redundancy Check (CRC)를 통해 잡음을 감지한다. 그리고 이미지의 가장 자리에서 보다 정확한 잡음 완화를 Extended Error Mask를 생성한 후, 이를 바탕으로 훼손된 픽셀에서 주변의 정상 픽셀의 값들의 평균값을 계산하여 잡음을 완화한다. 제안한 기법의 성능을 평가하기 위한 척도로는 Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index Method (SSIM)를 사용하였으며, 제안한 방법과 기존의 방법을 사용한 모의 실험 결과를 비교하여 성능을 평가하였다. Digital images or videos can contain noise during storage and transmission due to various reasons. In this paper, a novel noise mitigation method using adjacent pixels is proposed. This method is applicable to images with distorted pixels and uses the adjacent pixel values of damaged values of damaged pixels. Salt & pepper noise and Additive White Gaussian Noise (AWGN) are considered as noise environment. In Salt & Pepper noise environment, 0 or 255 values are searched to detect error. In AWGN environment, Cyclic Redundancy Check (CRC) is used to detect error. And extended error mask is created to accurate noise mitigation in boundary pixels. Then, based on extended error mask, APNMF mitigates noise. Furthermore, Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index Method (SSIM) is used to estimate the performance. And result of proposed method is compared with results of conventional methods in simulation.

Binaural Asymmetric Directional Microphone Algorithm with Automatic Switching Mode for Better Noise Reduction

김진률 한양대학교 2015 국내박사

Noise reduction algorithm on digital hearing aid has been used to improve speech quality and intelligibility at noisy signal. Noise reduction algorithm can be classified by the number of microphone; single channel- or multichannel- noise reduction. At the previous studies about the improvement of speech quality and intelligibility in noisy situation, single channel algorithm is only improved the performance of speech quality by normal and impaired hearing person. However, multichannel algorithm is improved the both performances. The algorithm that has two or more microphones is called a beamforming or spatial filtering. In order to change a directionality of input signals, the algorithm adjusts a phase difference corresponding to a distance of both microphones by additional delay according to the direction of input signal and controls relative amplitude of the input signal at each microphone by a constrained weighting function according to the direction of input signal. As a result, the directionality changes according to the direction of input signal. When the beamforming is used hearing aid, it has several weaknesses. First, the number of microphone is limited by size of hearing aid. That is why the directionality is constrained to the front or rear. Second, manual or automatic switching between non-directionality and directionality is uncomfortable for the users. So many users often do not use the algorithm. Third, the beamforming, that distort the input signal according to the direction, disrupts the brain functions when the direction of the mismatch between the desired signal and input signal is occurred. Human can listen to the speech or desired signal in noisy situation without any other device. It is because the brain functions such as Auditory Scene Analysis and auditory attention. Its phenomenon is demonstrated by the cocktail party effect. In other word, center auditory system of human’s brain play a sound source separator role in noisy situation. Most hearing impaired persons still have the brain functions. Even if an interest signal is front, beamforming has benefit. But if that is the others direction, the algorithm distort the input signal that want to hearing. That is because the brain functions can be disrupted through the beamforming. In order to overcome the above mentioned weaknesses, bilateral asymmetric directional microphone fitting is presented. The method has different directionality at each ear in order to maintain the brain functions. Left ear has directional mode to enhance the front signal, such as beamforming, and Right ear has omnidirectional mode to receive equal signals regardless of direction. Because of the input signal of right ear do not distort according to input direction, the brain functions connected right ear are better performance than that of left. Thereby, left ear has a benefit of directional mode. And right ear has a benefit omnidirectional mode that maintains the brain functions. Also the method removes the necessity for manual or automatic switching between non-directionality and directionality. That is why the method has both directional and omnidirectional mode. As above mentioned, the asymmetric directional microphone fitting has several benefits. But, a dominant noise, when locate in the side of directional mode, may be reduced. However, if a dominant noise locates in the side of omnidirectional mode, its noise may not be reduced. In other words, the performance of the method is expected to be dependent on the according to the direction of the input noise. That is because the directionality modes are not switched according to the direction of input noise. In my study, novel binaural asymmetric directional microphone algorithm was developed and evaluated. The proposed algorithm operates automatically directionality modes switching between left directional and right omnidirectional mode according to the input signal-to-noise ratio. When a dominant noise locates in the side of omnidirectional mode, the proposed algorithm detects the direction of the dominant noise and switches the directionality from omnidirectional to directional mode. MATLAB and Simulink are used to implement the algorithms. For the evaluation, the performance of detection of the dominant noise on the proposed algorithm was measured on 3 kind of scenario (non-reverberant, reverberant, realistic reverberant) by personal computer simulation. And the comparison of performance between the proposed algorithm and conventional asymmetric directional fitting was executed on personal computer simulation and KEMAR test. Finally, the proposed algorithm was tested by normal hearing person. The output signal-to-noise ratio, Perceptual Evaluation of Speech Quality (PESQ) and Hearing Aid Speech Quality (HASQI) are used as objective measurement. As subjective measurement, 10 normal hearing persons are tested by Comparison Mean Opinion Score (CMOS). The result of detection of dominant noise is higher accurate at all scenario (non-reverberant > realistic reverberant > reverberant). As result of objective measurement on personal computer simulation and KEMAR test, when a dominant noise locates in the side of directional mode, the objective measurements of the proposed algorithm is similar to conventional algorithm. But the objective measurements are higher than that of the conventional algorithm, when a dominant noise locates in the side of omnidirectional mode. Especially, objective measurement relative to intelligibility is high at KEMAR test than at personal computer simulation. At the result of CMOS on normal hearing person, the subjective quality of normal hearing person is slightly better on the proposed algorithm. In my study, novel binaural asymmetric directional microphone algorithm that automatically switches the directionality modes between both ears and adjusts the directionality on the one side ear according to the direction of input signal was presented. Through the evaluation on person computer simulation, KEMAR test, and normal hearing person, the proposed algorithm is better performance of objective and subjective measurement than conventional algorithm. It is more influenced by the automatically switching the directionality modes between left and right ear than by the adjusting the directionality on one side ear. Speech intelligibility and quality of normal hearing person is even high on noisy situation. That may be why the result of CMOS is slightly better on normal hearing person. In my study, novel binaural asymmetric directional microphone algorithm was developed and evaluated. I expect that the algorithm is applied to the hearing aid through additional clinical trials for hearing impaired person is tested.