• ETRI Journal
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• 제35권5호
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• pp.859-868
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• 2013

The active noise control (ANC) technique attenuates acoustic noise in a flexible and effective way. Traditional ANC design aims to minimize the residual noise energy, which is indiscriminative in the frequency domain. However, human hearing perception exhibits selective sensitivity for different frequency ranges. In this paper, we aim to improve the noise attenuation performance in perceptual perspective by incorporating noise weighting into ANC design. We also introduce psychoacoustic analysis to evaluate the sound quality of the residual noise by using a predictive pleasantness model, which combines four psychoacoustic parameters: loudness, sharpness, roughness, and tonality. Simulations on synthetic random noise and realistic noise show that our method improves the sound quality and that ITU-R 468 noise weighting even performs better than A-weighting.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.617-621
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• 2003

Existing loudness models are specified only to diotic sounds in spite of the fact that normal human beings hear dichotic sounds. Approximately, the arithmetic mean of loudness values of both ear signals has been suggested for the resultant perceived loudness. In this study, the dependence of overall loudness perception on the interaural level differences was investigated by the subjective tests. It was found that the larger the interaural level difference, the louder the perception than the mean of calculated loudness values at both ears and the lower the critical band rate or the reference level, the louder the perception than the mean value. A modified loudness model was proposed to he applicable to dichotic sounds by using the equivalent diotic levels.

• 음성과학
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• 제5권1호
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• pp.167-179
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• 1999

The hearing mechanism is a complicated system. Sound is generated by a source that sends out air pressure or power. The pressure or power makes the sound waves. These waves reach the eardrum, or tympanic membrane, which vibrates at a rate and magnitude proportional to the nature of the sound waves. The tympanic membrane transforms this vibration into the mechanical energy in the middle ear, which in turn converts it to the hydraulic energy in the fluid of the inner ear. The hydraulic energy stimulates the sensory cells of the inner ear which send neuroelectrical impulses to the central auditory nervous system. The passive perception of auditory information starts just here. The listener gives attention to the speech sound, differentiates the sound from background noise, and integrates his experience with similar sounds. The listener then puts all of these aspects of audition into the context of the moment to identify the nature of sound. This has a major role in human communication. This paper provides an overview of the nature and characteristics of sound, the structure and function of the auditory system, and the way in which sound is processed by the auditory system.

• 사상체질의학회지
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• 제12권2호
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• pp.17-33
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• 2000

Purpose of this study is to investigate the correlation between Sung-Jung' concept of Sasang Constitutional Medicine and Brain. So, After studying the meaning of Sung-Jung' concept of Sasang Constitutional Medicine, I made a comparative study through the structure, function, development of Brain. The conclusions were as follows. 1. Human's brain acts a rational, control his actions. and It manage human body's physiology and pathology. and It perceive his surroundings, express his emotion through comprehension, synthesis, judgement about information from various fields. and It's abnormality bring about a spiritual, bodily injury. Therefore, human's brain have many correlation with Sung-Jung' concept of Sasang Constitutional Medicine. 2. Neocortex' function have many correlation with Sung' concept of Hearing-Sight-Smell-Taste (聽視嗅味=sensation=a highly mental capacity) through Ear-Eye-Nose-Mouse(耳目鼻?). 3. Limbic-system'function have many correlation with Jung' concept of Sorrow-Anger-Pleasure-Joy(哀怒喜榮=emotion) through Lung-Spleen-Liver-Kidney(肺脾肝腎) 4. Brain-stem' function have many correlation with vitalistic concept through Qui of Sorrow - Anger - Pleasure - Joy(哀怒喜樂之氣)' rise and fall. 5. Relation of emotions and diseases through Limbic system and Autonomic nervous system have many correlation with relation of Sung-Jung and diseases of Sasang Constitutional Medicine 6. Left-hemisphere' function that has superior power of verbal, analysis, logicality, consideration have many correlation with tendency of Soeumin and Taeumin. and Right-hemisphere' function that has superior power of emotion, non-verbal, imagination, spatial perception have many correlation with tendency of Soyangin and Taeyangin.

• 대한전자공학회논문지SP
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• 제43권5호
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• pp.79-87
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• 2006

본 연구에서 인공 와우 환자의 잡음 상황에서 음성 신호 강조와 잡음 제거를 위한 전 처리로서 companding strategy를 적용하고 이를 평가하였다. Companding은 인간의 청각 특성인 two tone suppression에 기반하며 이는 음성 스펙트럼 피크를 강화하고 배경 잡음을 감소시킨다. 하지만 companding은 잡음 제거와 스펙트럼 피크의 강화에 효과적인 반면, 제한된 채널의 수와 비선형 블록으로 인한 음성 정보 손실의 교환 특성을 가진다. 따라서 본 연구에서는 잡음 제거와 음성 정보 손실의 정도가 상대적인 두 companding 구조를 설계하여 개인마다 잡음 상황에서 언어 인지 특성차이에 따른 적절한 필터 뱅크를 도출하였으며, 낮은 신호 대 잡음 비 환경에서 인공 와우 환자의 언어 인지 향상을 위한 방법을 제시하였다. 제안된 알고리즘은 잡음 밴드 시뮬레이션을 이용하여 정상인 5명에게 평가되었다. 모든 피실험자에게서 효과적인 언어 인지의 향상이 관측되었고, 각 피실험자가 선호하는 필터 뱅크는 다르게 나타났다.

• 정보처리학회논문지B
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• 제18B권6호
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• pp.333-340
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• 2011

인간-컴퓨터 상호 작용은 인간공학과 정보기술을 융합하여 인간과 컴퓨터와의 상호 작용 기술을 연구하는 학문이고, 그 중에서도 지능형 공간은 정보화 사회에서 소외될 수 있는 장애인에게 더욱 효과적인 사용 환경을 제공할 수 있는 중요한 연구 분야이다. 장애인을 위한 지능형 공간에서의 정보 지원 방법은 장애 유형에 따라 달라지는데, 본 논문은 정보 지원 대상을 청각 장애인으로 한정한다. 청각 장애인에게 직접 접촉을 통해 정보 제공 위치를 인지시키는 방법을 제외하면, 시선이 향하고 있는 곳에 정보를 표시하는 것이 가장 효율적인 정보 제공 방법이기 때문에, 시선 방향 검출 방법은 필수적이다. 우리는 이처럼 청각 장애인에게 실내 생활 지원 서비스를 제공하기 위해 반드시 필요한 시선 방향 검출 방법을 제안한다. 제안된 방법은 다시점 영상(Multi-view Camera Image) 내에서 검출된 사용자 영역 정보를 이용하여, 시점 별 수평/수직 방향 시선각 후보를 생성하고 후보 간의 크기 비교를 통해 사용자의 시선 방향을 계산한다. 실험 결과에서, 제안된 방법은 높은 시선 방향 검출 성능을 보이며, 장애인을 위한 시나리오를 수행할 수 있는 가능성을 보였다.

• 한국음향학회지
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• 제19권7호
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• pp.28-33
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• 2000

음성 신호의 효과적인 양자화를 위해서 인간의 청각 인지 특성을 이용하는 방법이 널리 사용되고 있다. 그러나 아직까지는 음성 스펙트럼의 크기 정보에 대한 인지 특성만을 이용하고 있을 뿐, 음성의 위상 정보는 그 중요성에 비해 간과되어 온 것이 사실이다. 본 논문에서는, 음향 신호로부터 청각 인지 측면에서 관련 없는 위상 성분을 추정하는 PIPE(Perceptually Irrelevant Phase Elimination) 방법을 제안하였다. 제안된 방법은 청각 특성이 critical band 대역 내의 상대적인 위상 관계에 민감하다는 관측 결과에 근거하여, 일반적인 stationary 푸리에(Fourier) 신호와 고조파(harmonic) 신호에 대해 각각 인지 측면에서 관련 없는 위상을 판별하는 방법을 제공한다. 제안된 방법을 음성 분석-합성(analysis / synthesis) 시스템에 적용함으로써 일부 위상 정보만을 이용해 음성을 복원하였으며, 청취 실험 결과 제안된 방법의 효율성을 알 수 있었다.

• ETRI Journal
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• 제39권6호
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• pp.832-840
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• 2017

Recently, deep recurrent neural networks have achieved great success in various machine learning tasks, and have also been applied for sound event detection. The detection of temporally overlapping sound events in realistic environments is much more challenging than in monophonic detection problems. In this paper, we present an approach to improve the accuracy of polyphonic sound event detection in multichannel audio based on gated recurrent neural networks in combination with auditory spectral features. In the proposed method, human hearing perception-based spatial and spectral-domain noise-reduced harmonic features are extracted from multichannel audio and used as high-resolution spectral inputs to train gated recurrent neural networks. This provides a fast and stable convergence rate compared to long short-term memory recurrent neural networks. Our evaluation reveals that the proposed method outperforms the conventional approaches.

• 한국소음진동공학회논문집
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• 제16권9호
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• pp.897-903
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• 2006

The reduction of the vehicle interior noise has been the main interest of noise and vibration harshness (NVH) engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. In particular, the heating, ventilation and air conditioning (HVAC) system sound among the vehicle interior noise has been reflected sensitively in psychoacoustics view point. Even though the HVAC noise is not louder than overall noise level, it clearly affects subjective perception to drivers in the way of making to be nervous or annoyed. Therefore, these days a vehicle engineer takes aim at developing sound quality as well as reduction of noise. In this paper, we acquired noises in the HVAC from many vehicles. Through the objective and subjective sound quality (SQ) evaluation with acquiring noises recorded by the vehicle HVAC system, the simple and multiple regression models were obtained for the subjective evaluation 'Pleasant' using the semantic differential method (SDM). The regression procedure also allows you to produce diagnostic statistics to evaluate the regression estimates including appropriation and accuracy. Furthermore, the neural network (NN) model were obtained using three inputs(loudness, sharpness and roughness) of the SQ metrics and one output(subjective 'Pleasant'). Because human's perception is very complex and hard to estimate their pattern, we used NN model. The estimated models were compared with correlations between output indexes of SQ and hearing test results for verification data 'Pleasant'. As a result of application of the SQ indexes, the NN model was shown with the largest correlation of SQ indexes and we found possibilities to predict the SQ metrics.

• Journal of Audiology & Otology
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• 제25권2호
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• pp.65-71
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• 2021

Background and Objectives: In masking level difference (MLD), the masked detection threshold for a signal is determined as a function of the relative interaural differences between the signal and the masker. Study 1 analyzed the results of school-aged children with good school performance in the MLD test, and study 2 compared their results with those of a group of children with poor academic performance. Subjects and Methods: Study 1 was conducted with 47 school-aged children with good academic performance (GI) and study 2 was carried out with 32 school-aged children with poor academic performance (GII). The inclusion criteria adopted for both studies were hearing thresholds within normal limits in basic audiological evaluation. Study 1 also considered normal performance in the central auditory processing test battery and absence of auditory complaints and/or of attention, language or speech issues. The MLD test was administered with a pure pulsatile tone of 500 Hz, in a binaural mode and intensity of 50 dBSL, using a CD player and audiometer. Results: In study 1, no significant correlation was observed, considering the influence of the variables age and sex in relation to the results obtained in homophase (SoNo), antiphase (SπNo) and MLD threshold conditions. The final mean MLD threshold was 13.66 dB. In study 2, the variables did not influence the test performance either. There was a significant difference between test results in SπNo conditions of the two groups, while no differences were found both in SoNo conditions and the final result of MLD. Conclusions: In study 1, the cut-off criterion of school-aged children in the MLD test was 9.3 dB. The variables (sex and age) did not interfere with the MLD results. In study 2, school performance did not differ in the MLD results. GII group showed inferior results than GI group, only in SπNo condition.