• Journal of Audiology & Otology
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• 제24권4호
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• pp.180-190
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• 2020

Background and Objectives: Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. Subjects and Methods: Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. Results: There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (p=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (p=0.029). Conclusions: Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener's subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.

• 대한청각학회지
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• 제24권4호
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• pp.180-190
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• 2020

Background and Objectives: Although many studies have evaluated the effect of the digital noise reduction (DNR) algorithm of hearing aids (HAs) on speech recognition, there are few studies on the effect of DNR on music perception. Therefore, we aimed to evaluate the effect of DNR on music, in addition to speech perception, using objective and subjective measurements. Subjects and Methods: Sixteen HA users participated in this study (58.00±10.44 years; 3 males and 13 females). The objective assessment of speech and music perception was based on the Korean version of the Clinical Assessment of Music Perception test and word and sentence recognition scores. Meanwhile, for the subjective assessment, the quality rating of speech and music as well as self-reported HA benefits were evaluated. Results: There was no improvement conferred with DNR of HAs on the objective assessment tests of speech and music perception. The pitch discrimination at 262 Hz in the DNR-off condition was better than that in the unaided condition (p=0.024); however, the unaided condition and the DNR-on conditions did not differ. In the Korean music background questionnaire, responses regarding ease of communication were better in the DNR-on condition than in the DNR-off condition (p=0.029). Conclusions: Speech and music perception or sound quality did not improve with the activation of DNR. However, DNR positively influenced the listener's subjective listening comfort. The DNR-off condition in HAs may be beneficial for pitch discrimination at some frequencies.

• 대한청각학회지
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• 제24권1호
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• pp.1-9
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• 2020

Auditory scene analysis is defined as a listener's ability to segregate a meaningful message from meaningless background noise in a listening environment. To gain better understanding of auditory perception in terms of message integration and segregation ability among concurrent signals, we aimed to systematically review the size of auditory scenes among individuals. A total of seven electronic databases were searched from 2000 to the present with related key terms. Using our inclusion criteria, 4,507 articles were classified according to four sequential steps-identification, screening, eligibility, included. Following study selection, the quality of four included articles was evaluated using the CAMARADES checklist. In general, studies concluded that the size of auditory scene increased as the number of sound sources increased; however, when the number of sources was five or higher, the listener's auditory scene analysis reached its maximum capability. Unfortunately, the score of study quality was not determined to be very high, and the number of articles used to calculate mean effect size and statistical significance was insufficient to draw significant conclusions. We suggest that study design and materials that consider realistic listening environments should be used in further studies to deep understand the nature of auditory scene analysis within various groups.

• Journal of Audiology & Otology
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• 제24권1호
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• pp.1-9
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• 2020

Auditory scene analysis is defined as a listener's ability to segregate a meaningful message from meaningless background noise in a listening environment. To gain better understanding of auditory perception in terms of message integration and segregation ability among concurrent signals, we aimed to systematically review the size of auditory scenes among individuals. A total of seven electronic databases were searched from 2000 to the present with related key terms. Using our inclusion criteria, 4,507 articles were classified according to four sequential steps-identification, screening, eligibility, included. Following study selection, the quality of four included articles was evaluated using the CAMARADES checklist. In general, studies concluded that the size of auditory scene increased as the number of sound sources increased; however, when the number of sources was five or higher, the listener's auditory scene analysis reached its maximum capability. Unfortunately, the score of study quality was not determined to be very high, and the number of articles used to calculate mean effect size and statistical significance was insufficient to draw significant conclusions. We suggest that study design and materials that consider realistic listening environments should be used in further studies to deep understand the nature of auditory scene analysis within various groups.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 2호
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• pp.57-60
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• 1998

This paper adopts the psychoacoustical methodology to evaluate the acoustical qualities of rooms and describes some of the results of an attempt to develop such a test. In order to investigate the effect of hall response to subjects, a subjective experiment was performed in artificially simulated sound fields. Pairs of sounds having differences in duration/frequency were presented to a subject and the subject's responses were recorded. The stimuli were varied through an auralization system that simulates three different rooms. It was found that duration/frequency discrimination is influenced by the room conditions and that these discrimination procedures may form the basis for assessment of room acoustics.

• 대한인간공학회지
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• 제17권1호
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• pp.23-36
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• 1998

The primary objective of this research was to establish and quantify the relationship between the physical degradation factors of multimedia telecommunications (teleconferencing) system and Subjective human perception. The research was performed in two stages. A field survey of the real users and pilot experiments were carried out in the first stage to determine customers' major complaints and corresponding system degradation factors. A prototype teleconferencing simulator was developed in two separate sound-treated chambers equipped with audio/video equipment running under a custom-developed software program. In the second stage, simulation experiments using the semantic differential methodology were performed utilizing 26 paid participants (14 college students and 12 housewives). The results indicated that audio/video synchronization and the frame rate were the main system factors for both subject groups, but different pattern of factors' influence was found according to the group, implying that the system configuration would hopefully accommodate the characteristics of the end users. Also, a single quality index, developed for system preference, was revealed to be highly correlated with user satisfaction. The results provide some fundamental data on the human subjective perception of multimedia telecommunications quality, and further can help establish the quality standards to enhance service level.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.311-317
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• 2007

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• 한국소음진동공학회논문집
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• 제18권4호
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• pp.393-399
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• 2008

The reduction of the Vehicle interior noise has been the main interest of NVH engineers. The driver's perception on the vehicle noise is affected largely by psychoacoustic characteristic of the noise as well as the SPL. The previous methods to evaluation of the SQ about vehicle interior noise are linear regression analysis of subjective SQ metrics by statistics and the estimation of the subjective SQ values by neural network. But these are so depended on jury test very much that they result in many difficulties. So, to reduce jury test weight, we suggested a new method using Mahalanobis distance for SQ evaluation. And, optimal characteristic values influenced on the result of the SQ evaluation were derived by signal to noise ratio(SN ratio) of the Taguchi method. Finally, the new method to evaluate SQ is constructed using Mahalanobis-Taguchi system(MTS). Furthermore, the MTS method for SQ evaluation was compared by the result of SQ grade table at the previous study and their virtues and faults introduced.

• 성인간호학회지
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• 제13권2호
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• pp.209-222
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• 2001

The environment in the ICU leads to negative changes in a patient's usual sleep pattern and so contributes negatively to the patient's health condition as compared to patients in general wards. Therefore, it is thought that an important nursing intervention would be to identify the relation between noise and sleep patterns which play an important role in illness recovery. The purpose of the present study was to explore the relationship between noise in the ICU and the sleep pattern of patients admitted to the ICU. A descriptive correlation design was used to examine the relationship. Thirty-four subjects were recruited from a Medical ICU (MICU), Surgical ICU (SICU) and Coronary Care Unit (CCU) at a large university hospital in Suwon. Data were collected from September 28 to October 31 in 1999. In the present study, noise was categorized into noise level and patients' perception of noise. The objective noise level was measured using the A-Weighted Sound Level Meter. The patients' preception of noise was measured using a self-reported questionnaire developed by the researcher. Sleep patterns in this study includes both quantity and quality of sleep. These were measured using open ended questionnaires and the 'Korean Sleep Scale A' developed by Oh, Song, Kim(1998). The data was analyzed using the SPSS-WIN to test the research question, Pearson product moment correlation coefficient was run. Ancillary analysis were conducted with demographic variables to determine their relation to the main study variables. For the ancillary analysis, t-test and one-way ANOVAs were performed. The results of the present study are summerized as follows : 1. The total mean of objective noise level (10pm-6am) was 56.2dB. The means for night time noise level in individual ICUs for the SICU, MICU and CCU, were 58.7dB, 58.6dB and 48.3dB, respectively. The total mean for patients' noise perception was 42.8 out of a maximum possible score of 76. For item means of noise perception, the one ranked highest was "conversations between doctors and nurses" (3.2). The one ranked lowest was "noise from the radio" (1.2). Regarding the degree of perception for each type of noise source, the one ranked highest was "equipment noise" (2.6), the second was "conversation between medical staff" (2.4), the third was "conversation between patients, caregivers and visitors" (2.3), and the one ranked lowest was "environment noise" (1.8). 2. Looking at quantity of sleep of ICU patients, the mean nocturnal sleep time was found to be 4.9 hours. The total mean of sleep quality for ICU patients was 21.0 out of a maximum possible score of 40. 3. The relationship between perception of noise and quantity of sleep was statistically significant(r= - .41, p<.05). The relationship between perception of noise and quality of sleep was also statistically significant(r= - .47, p<.01). The results of the study indicate that personal perception of noise is related to sleep patterns. Therefore, it is suggested that nursing interventions be developed to reduce the degree of personal perception of noise and, thus, decrease sleep pattern disturbances in patients in the ICU.

• 전기전자학회논문지
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• 제23권3호
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• pp.893-898
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• 2019

시주파수 표현법은 시간과 주파수의 2차원 평면에 대하여 신호의 크기 혹은 에너지 밀도의 분포를 표현하는 방법이다. 이러한 기술은 시변 신호(Time-varying signal)의 특성 분석에 유용하다. 연주음은 대표적인 시변신호이며 특성 분석을 위하여 시주파수 표현법을 사용할 수 있다. 최근 악기에 사운더를 부착하여 음질을 변화시키는 작업이 주목 받고 있다. 비교적 저렴한 비용을 지불하고 음질을 변화시켜 주관적인 평가를 개선하려는 시도로 시행되고 있다. 이러한 연주신호는 시간영역에서는 사운더가 없는 악기 원형으로 연주한 경우와 차이점을 찾기가 어렵지만 주파수 영역, 그리고 시간-주파수 영역에서 분석하면 차이점을 쉽게 볼 수 있다. 본 논문에서는 사운더를 부착한 악기의 연주신호를 주파수 영역에서 분석하여 사운더의 효과를 확인하고 더 나아가 시주파수 표현법을 활용하여 사운더의 영향을 분석한다. 악기에 따라 사운더의 효과는 다르지만 대체로 인간의 주관적인 평가에 영향을 주는 중간주파수대에서 강화된 효과를 확인할 수 있다.