• 한국소음진동공학회논문집
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• 제23권1호
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• pp.3-8
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• 2013

Recently, the impact on hearing induced by using of portable audio equipment have been actively studied. In general, Because they turn the volume up with loud background noise, they may expose to louder noise. In this study, we investigated the maximum noise level of 20 the domestic potable audio equipment and estimated the impact of the hearing induced by portable audio equipment in according to exposure time. As a result, the use of portable audio equipment is assumed to be more three hours when the level of more than 50 % of volume is most likely to affect the hearing.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2009년도 IWAIT
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• pp.390-395
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• 2009

The robustness of audio fingerprinting system in a noisy environment is a principal challenge in the area of content-based audio retrieval. The selected feature for the audio fingerprints must be robust in a noisy environment and the computational complexity of the searching algorithm must be low enough to be executed in real-time. The audio fingerprint proposed by Philips uses expanded hash table lookup to compensate errors introduced by noise. The expanded hash table lookup increases the searching complexity by a factor of 33 times the degree of expansion defined by the hamming distance. We propose a new method to improve noise robustness of audio fingerprinting in noise environment using predominant pitch which reduces the bit error of created hash values. The sub-fingerprint of our approach method is computed in each time frames of audio. The time frame is transformed into the frequency domain using FFT. The obtained audio spectrum is divided into 33 critical bands. Finally, the 32-bit hash value is computed by difference of each bands of energy. And only store bits near predominant pitch. Predominant pitches are extracted in each time frames of audio. The extraction process consists of harmonic enhancement, harmonic summation and selecting a band among critical bands.

• 전기의세계
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• 제29권12호
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• pp.798-803
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• 1980

A computer program for noise analysis of the audio circuit is developed. The application of the program to the equalizer, low frequency amplifier of radio circuit and cascaded amplifier show good results. The general noise analysis method for cascade operational amplifier is presented. The noise spectral power density is calculated for a resonator active filter.

• ETRI Journal
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• 제28권4호
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• pp.509-512
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• 2006

In a real environment, sound recordings are commonly distorted by channel and background noise, and the performance of audio identification is mainly degraded by them. Recently, Philips introduced a robust and efficient audio fingerprinting scheme applying a differential (high-pass filtering) to the frequency-time sequence of the perceptual filter-bank energies. In practice, however, the robustness of the audio fingerprinting scheme is still important in a real environment. In this letter, we introduce alternatives to the frequency-temporal filtering combination for an extension method of Philips' audio fingerprinting scheme to achieve robustness to channel and background noise under the conditions of a real situation. Our experimental results show that the proposed filtering combination improves noise robustness in audio identification.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1175-1176
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• 2008

This paper deals with the study on the development of Audio SMPS with reduced noise. The noise defined here is in the range between 20 - 20 kHz frequency that a human can listen. We proposed a design method for Audio SMPS, which reduce noise and raise audio performances. This was achieved by new electronic elements, grounding, pattern, and shielding methods.

• 한국위성정보통신학회논문지
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• 제8권1호
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• pp.31-34
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• 2013

본 논문은 4세대 이동통신인 Long Term Evolution (LTE) 단말기에 의해 발생된 간섭 신호가 음향기기에 유입되었을 때 음향기기의 잡음영향에 대해 검토하였다. 먼저, LTE 송신 신호에 대한 분석 및 측정을 바탕으로 음향기기에 간섭을 주는 LTE 간섭 신호는 송신 전력의 크기에 의해 결정됨을 확인하였다. 또한, LTE 단말기의 송신전력 및 단말기와 음향기기간의 거리를 변화시키면서 발생하는 음향기기의 잡음을 측정하였다. 측정 결과, LTE 단말기가 최대 전력(22 dBm)을 송신하더라도 단말기와 음향기기의 거리를 25 cm 이상 이격시킴으로써 음향기기에서 발생하는 잡음을 방지할 수 있었다.

• 한국전자통신학회논문지
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• 제10권2호
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• pp.233-238
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• 2015

본 논문에서는 FTV(Free-viewpoint TV) 서비스에서, 몰입도를 향상시킬 수 있는 유효 잡음 이용 입체 음향효과 방법을 제안한다. 농구장에서 초지향성 마이크 및 무선 마이크를 사용하여 선수와 심판의 연속적인 음향 정보를 획득함으로써 주파수 스펙트럼을 관찰하였으며, 스펙트럼을 분석하여 시청자가 Zoom-in을 할 경우, 유효 주파수 여부를 판단하였다. 따라서 FTV 서비스에서 시청자가 피사체를 향해 Zoom-in 시, 제거대상이었던 잡음을 활용할 필요가 있음을 제시하였다. 본 연구는 향후 FTV의 입체 음향 연구에 활용될 것으로 기대된다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.912-918
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• 1994

Poor speech intelligibility in an air traffic control room is frequently a result of many, quite different causes and occasionally leads to complaints of the controller personnel. The paper describes a sequence of successful tasks performed in a local control room. The initial measurements included an investigation of the background noise (caused by fans, air condition, computer and radar equipment) and performance checks of the electronic audio and communication equipment with respect to the audio transmission behavior. The spectral composition of the noise as well as the characteristics of the audio communication path between the controllers and the pilots(which showed a loss of spectral information in the audio band due to built-in notch filters for the suppression of control tones) required adaptations of the amplitude behavior of the amplifiers through user adjustable tone controls. The radar console fans, which contributed significantly to the overall noise floor of the room, underwent a substantial reconstruction by replacing the tight mounting with an elastic double suspension, reducing the noise level by 50%. Finally, a possible source of untimely fatigue of the controllers during their working hours has been found in strong spectral components of the noise above the audio band, radiated by numerous video monitors in the control through vibrating components excited by the line frequency of the video signal.

• 한국음향학회지
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• 제33권3호
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• pp.210-215
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• 2014

오디오 핑거프린팅 기술은 잡음과 에코 등으로 인한 왜곡에도 성공적으로 음원을 식별해야한다. 이러한 오디오 핑거프린팅 기술을 TV광고식별에 적용하고자 한다. 본 논문은 TV 광고 식별을 위한 강인한 오디오 핑거프린팅 방식을 제안한다. 제안된 방법에서 사용되는 Constant Q 변환 기반에서 추출된 현저한 오디오 피크 쌍 핑거프린트는 실제 다양한 잡음환경에서 오디오 핑거프린팅 시스템의 정확도를 향상시키고, 낮은 복잡도를 가진다. 실험결과는 제안된 방식이 기존의 오디오 핑거프린팅 방식에 비해 다양한 잡음환경에서도 안정적이며 신뢰할 수 있는 검색 정확도를 제공함을 보여준다.

• 방송공학회논문지
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• 제26권3호
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• pp.327-330
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• 2021

본 논문에서는 3D 오디오 부호기의 성능 향상을 위해 새로운 잡음 채움 기법을 제안한다. 제안한 잡음 채움 기법에서는 핵심 대역을 IGF 시작 주파수까지가 아니라 MAX_SFB로 설정되는 영역까지로 제한한다. 그리고, IGF 입력 패치의 모든 주파수 영역에 잡음 채움이 수행되도록 한다. 본 논문에서 수정된 잡음 채움 기법의 성능은 MUSHRA 테스트를 통해 평가되었고, 그 결과 기존의 방법보다 우수한 성능을 보임을 입증한다.