• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.1
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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.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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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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• v.29 no.12
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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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• v.28 no.4
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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.

• Proceedings of the IEEK Conference
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• 2008.06a
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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.

• Journal of Satellite, Information and Communications
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• v.8 no.1
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• pp.31-34
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• 2013

This paper deals with the interfering audio noise caused by LTE(Long Term Evolution) UE(User Equipment) which is 4th generation mobile communications on audio devices. At first, we realized that the interfering signal of the LTE UE is determined by the transmit power of the LTE UE through analysis and measurement. Then, we performed to measure audio noise level according to the variation of transmitting power level and separation distance between the LTE UE and an audio device. As a result, it is required that minimum separation distance should be 25 cm and above in order to protect audio device from the interference noise of the LTE UE with the maximum transmit power level of 22 dBm.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.2
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• pp.233-238
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• 2015

In this paper, we proposed that immersive audio effect method using the effective noise to improve engagement in free-viewpoint TV(FTV) service. In the basketball court, we monitored the frequency spectrums by acquiring continuous audio data of players and referee using shotgun and wireless microphone. By analyzing this spectrum, in case that users zoomed in, we determined whether it is effective frequency or not. Therefore when users using FTV service zoom in toward the object, it is proposed that we need to utilize unnecessary noise instead of removing that. it will be able to be useful for an immersive audio implementation of FTV.

• Proceedings of the Acoustical Society of Korea Conference
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• 1994.06a
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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.

• The Journal of the Acoustical Society of Korea
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• v.33 no.3
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• pp.210-215
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• 2014

In spite of distortion caused by noise and echo, the audio fingerprinting technique must identify successfully an audio source. This audio fingerprinting technique is applying for TV commercial advertisement identification. In this paper, we propose a robust audio fingerprinting method for TV commercial advertisement identification. In the proposed method, a prominent audio peak pair fingerprint based on constant Q transform improves the accuracy of the audio fingerprinting system in real noisy environments. Experimental results confirm that the proposed method is quite robust than previous audio fingerprinting method in different noise conditions and achieves promising accurate results.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.327-330
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• 2021

In this paper, a new noise filling method is proposed for improving the performance of the 3D audio codec. In the new method, the core band is limited up to MAX_SFB, not up to the IGF start frequency. And the noise filling is applied to all frequency range of the IGF source patches. We conduct the MUSHRA test and find that the proposed noise filling method demonstrates better performance than the conventional method.