• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.495-498
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• 2004

In the sound insulation measurements, the influence of background (extraneous) noise is often serious problem and how to reduce its effect and to improve the signal-to-noise(S/N) ratio is an important theme. As the background noise, such extraneous noises as road traffic noise and machine noise often disturb the measurement. In laboratory measurements on specimens with high sound insulation performances, even the internal noise of the measurement system can become a problem. To improve the signal-to-noise ratio and to improve the measurement accuracy, various kinds of digital signal processing techniques can be applied. In this paper, four kinds of digital signal processing techniques are applied and their effectiveness is examined by a simple sound insulation measurement.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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• pp.441-444
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• 2004

In the sound insulation measurements, the influence of background (extraneous) noise is often serious problem and how to reduce its effect and to improve the signal-to-noise(S/N) ratio is an important theme. As the background noise, such extraneous noises as road traffic noise and machine noise often disturb the measurement. In laboratory measurements on specimens with high sound insulation performances, even the internal noise of the measurement system can become a problem. To improve the signal-to-noise ratio and to improve the measurement accuracy, various kinds of digital signal processing techniques can be applied. In this paper, four kinds of digital signal processing techniques are applied and their effectiveness is examined through field measurements.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.363-366
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• 2005

Social survey and auditory experiment on residential noises such as floor impact, air-bome, bathroom, drainage and traffic noises were conducted to investigate the effects of sensitivity and background noise levels on subjective response to residential noises. Results of survey showed that multiple questions for sensitivity to noise have a more power for discrimination against subjective response to noise than single question. It was also found that the correlation between sensitivity and annoyance was relatively low, but the differences in annoyance between sensitivity groups were significant. Result of auditory experiment showed that effects of sensitivity on annoyance were different according to noise type and noise level. It was also shown that the difference in annoyance between the lowest sensitive stoup and the highest sensitive group was significant in low noise level. The effects of background noise on subjective responses to noise was also different according to noise source and noise level, and were significant in low noise level of airborne and drainage noise.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.694-699
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• 2004

The purpose of this study is to estimate the availability of acoustic emission method to the internal leak of the valves at nuclear power plants. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. From the comparison of the background noise data with the experimental results as to relation between leak flow and acoustic signal, the minimum leak flow rates that can be detected by acoustic signal was suggested. When the background levels are higher than the acoustic signal, the method described below was considered that the analysis the remainder among the background noise frequency spectrum and the acoustic signal spectrum become a very useful leak detection method. A few experimental examples of the spectrum analysis that varied the background noise characteristic were given.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.70-72
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• 2009

In this paper, nonlinear active noise control(ANC) of a 3rd-order Volterra system, which is robust to background noise variation, is proposed along with a variable step-size Gauss-Seidel pseudo affine projection(VSSGS-PAP) algorithm. Simulation results demonstrate that the proposed approach yields better nonlinear ANC performance in a background noise variation environment, compared with the conventional methods for the nonlinear ANC.

• 한국통신학회논문지
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• 제34권3A호
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• pp.272-280
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• 2009

배경잡음 측정은 전파환경 조사 및 주파수 점유율의 비교기준인 임계레벨을 산출하는데 반드시 수행되어야 하는 매우 중요한 과정이다. 배경잡음 측정은 측정대상 대역에서 가급적 잡음만으로 구성된 부대역을 선정하고, 선정된 표본 부대역에 대하여 잡음전력을 측정하여 대상대역에 대한 대표값으로 사용하는 과정으로 이루어진다. 본 논문에서는 배경잡음으로 백색가우시안 잡음을 가정하고, 잡음 측정의 첫 번째 단계에서 신호가 적고 대부분 잡음으로만 구성된 대역을 선별하는데 적용될 수 있는 특이값 분해 (singular value decomposition, SVD)를 이용한 잡음대역 선정 방법을 제안한다. 기존에 널리 쓰여지는 방법인 신호강도확률분포 (amplitude probability distribution, APD) 방법과의 성능비교를 통하여 우수성을 확인하였다.

• 대한조선학회논문집
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• 제44권4호
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• pp.408-416
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• 2007

This paper summarizes an experimental study on the marine propeller BPF noise. The main objective of this study is to show the worthiness of the noise measurement at the MOERI middle size cavitation tunnel and to acquire useful propeller noise data. Background noise of MOERI(Maritime and Ocean Engineering Research Institute) cavitation tunnel is experimentally analyzed. Experiment carried out in the MOERI cavitation tunnel with wake screen or dummy body, which is simulated the wake. Propeller BPF noise is measured under various operating conditions. In order to secure the reliance of measured propeller noise dada, background noise of each operating conditions are measured and analyzed. The noise characteristics are analyzed according to the operating condition.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.740-745
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• 1994

In the actual situation of measuring the environmental noise, it is very often that only the resultant phenomenon fluctuation contaminated by the additional noise of arbitrary distribution type can be observed. Furthermore, the observed data is usually given in a sound level form the purpose of estimating only the undisturbed objective output response, some estimation method is necessary to reasonably remove the effect of the above additional noise. In this paper, first, a mathematical model of arbitrary sound insulation systems is introduced in the form of a linear system on intensity scale, by using the well-known additive property of energy quantities. Next, some estimation method of the output response under the existence of background noise is derived. Then, based on the expression of the above estimation method, a new prediction method of only the output response probability function form for arbitrary sound insulation systems without. a background noise is proposed by use of observed data contaminated by a background noise. Finally, the effectiveness of the proposed method is confirmed experimentally too by applying it to the actual various type sound wall systems.

• 한국정보전자통신기술학회논문지
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• 제6권1호
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• pp.23-28
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• 2013

본 논문에서는 모바일 환경에서 dual microphone을 이용하여 배경 잡음을 효율적으로 제거하는 방법을 제안한다. 참조 마이크와 주 입력 마이크로부터 측정된 신호를 각각 FDAF의 참조신호와 주 입력 신호로 하여 잡음 제거를 수행한 뒤에 MMSE-LSA를 이용하여 잔여 잡음 및 배경 잡음을 추정하여 제거 한다. 이때 일관성 있는 잡음 제거 성능을 위해 두 마이크 신호의 PLD를 이용한 VAD 결과를 사용한다.

• 대한전자공학회논문지SP
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• 제41권6호
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• pp.295-302
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• 2004

음성 신호처리의 분야에서 잡음처리의 문제는 지금도 중요한 연구 과제이다. 특히 배경잡음이 음성의 인식율을 현저히 저하시키는 것은 오래 전부터 주목 받고 있다. 배경잡음으로는 실제 환경에 존재하는 비정상적인 다양한 잡음, 예를 들면 도로에서의 자동차의 주행잡음, 프린터의 구동잡음 등이 있다. 이런 종류에 대한 잡음 대책은 단순하지 않고, 종래의 위너 필터(Wiener filter) 등에 의한 선형적인 잡음제거 법보다도, 보다 고도한 잡음억제 기술이 필요하다. 본 논문에서는, 이러한 방법의 한 가지 시도로써 백색잡음 및 위에 기술한 비정상적인 배경잡음에 의해 열화된 음성을 상호억제로 불리는 인간의 청각기관에서의 잡음억제 기능 모델을 사용하여 음성강화 법의 알고리즘을 소개한다. 제안된 알고리즘은 스펙트럴 왜곡(SD)의 평가방법을 통하여 백색잡음 및 유색잡음에 대해서 효과적인 것을 보여준다.