• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.662-663
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• 2014

In most vehicle manufactures have traditionally relied on find-fix method of human auditor, mainly due to variation excitation source. To solve the BSR noise, the requirements for BSR test are presented in terms of detection of noise source, analysis of time-frequency and sound pressure, sound quality for noise. A number of new technology direction, particularly in the field of noise source identification application and psycho-acoustics from the Zwicker's sound quality parameter, the computed objective sound metrics and subjective jury test result.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.11
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• pp.1202-1213
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• 2009

Muffler sound quality of a vehicle has widely been evaluated using commercial softwares. However, the commercial softwares are providing only simple sound quality index. To get better sound quality evaluation method of the muffler, a new approach is suggested based on the subjective sound quality test. The suggested subjective sound quality evaluation method is refined with the fuzzy theory. The developed method is applied for the evaluation of various kinds of vehicle muffler sounds.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.145-148
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• 2004

Until now, product mostly has revealed physical quantities created by the standpoint of engineers. Consumers, however, perceive and evaluate products on the non-physical characteristics, such as feelings, emotions, and experiences in different social and cultural situations. Especially, for the household appliances such as a refrigerator, the sound is heavily related to the satisfaction of a customer who is a real user of the product and is very important factor to decide purchasing as well as visual design. Therefore, in this research, not only the simple sound pressure level but also the consumer's sense of hearing evaluate the noise from the refrigerator. And also, in order to improve the quality of sound through the design change, the consumer's evaluation is analyzed and related to the engineering quantities.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.5 s.122
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• pp.398-404
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• 2007

In this study, the sensitivity of annoyance was investigated by the subjective jury test for the variations of the frequency components along with various sound pressure levels of sixteen environmental noise sources. Annoyance was, also, evaluated for the road traffic noises. Sound pressure levels were $54{\sim}84\;dB$ which individually divided frequency components with eight bands of equally three bark bands. The results show that vehicle traffic noise is recognized as the most serious environment noise source. The sensitivity of human perception of annoyance in frequency bands is quite different from A-weighting curve. The annoyance found out to be more sensitive in high frequency region and reached its maximum in 3.4 kHz.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.4 s.121
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• pp.298-309
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• 2007

There are various sounds in the car as much as cars have many mechanical parts. These sounds make various psychological development. The international competition in car markets has continuously required the research about the sound quality of a car. The domestic car makers have also invested a lot of money for the research and development of sound quality. Car axle plays an important role in a vehicle and its NVH development is also important. By this time, NVH development of car axle is mainly based on the reduction of sound pressure level (dBA), which cannot gives, the satisfaction to the customers in view of the sound quality of a vehicle. Therefore, in this paper, a sound quality index evaluating the sound quality of axle noise based on human sensibility is developed.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.393-396
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• 2001

차량 주행시 발생되는 소위 mimic 소음은 접이식 outside mirror의 접합부에서 발생하는 이음(異音)으로서 예민한 승객에게 지적된다. Mimic 소음은 2kHz이 상의 고주파 영역에서 특정 대역에 간헐적으로 발생하는 소음이며, 시간에 대해 앙상블 에버리지를 하는 일반적인 분석 방법으로는 나타나지 않는다. 그러나 주의 깊은 청취에 의해 그 존재를 분명히 느낄 수 있으므로 다꾸찌 시험 계획법에 의거 실험 샘플을 제작하여 녹음한 뒤, 청음 평가를 통하여 개선하는 과정을 거쳤다. 분석 결과 mimic 소음은 folding gap의 폭보다는 균일도를 유지하는 것이 중요하며, gap내의 공동(공동, cavity)을 메워 주는 것이 효과적이라는 결론을 얻었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.401-405
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• 2003

Sound quality is becoming a major concern in optical disc drives (ODD). In order to improve the sound quality of slim type ODDs, we changed lead screw pitch and firmware algorithm in the seek mode. To evaluate the sound quality, the PCM (Paired Comparison Method) was adopted and the result was compared with the time-averaged loudness spectrum. Sound signals were also recorded and modified by increasing or decreasing selected frequency bands to verify their sensitivities to the sound quality. As a result of jury test, preferred frequency bands are associated with the time-averaged loudness spectrum.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.540-543
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• 2011

The vehicle's warning sounds are one of the important parts of overall vehicle quality, so the study of these sounds is increasing. In this study, the experiment of reproducing performance related to speaker position was studied. Based on the result of jury test, sound analysis method was developed to reflect the perception of warning sound according to vehicle speed and the development process of warning sounds was suggested.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.122-129
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• 2013

The vehicle's waning sounds are used for the purpose of informing the specific situation to the driver. In the past, the warning sounds were developed in terms of a simple notification. With the increasing importance of the emotional quality of vehicle, the research in terms of sound quality has been actively conducted. The desired sounds are dependent upon customer expectation and usage requirements. And it based on cultural or regional difference and personal preference. In this paper, the preference study considering the sale region and personal preference is introduced. Jury test for subjective evaluation are carried out and the difference in preference is analyzed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.519-524
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• 2013

The purpose of this study is that developing the index which evaluate sound quality of door latch and improving its sound quality through that results. For that, various operating sound of door latch was used for jury test. Loudness and sharpness related metrics are dominant in sound quality index we developed. This research investigate the main transfer path of its operating sound through sound field visualization and get conclusion that could reduce the impact sound of door latch. Therefore, we could verify sound quality improvement of modified product by using sound quality index.