• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.3 s.120
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• pp.241-248
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• 2007

A study has been conducted to investigate the subjective responses of loudness and annoyance according to the exposed time of urban traffic noise in controlled laboratory environment. To make a closer inspection into psychological response relevant to noise characteristics while varying the time of exposure to noise, the subjects were presented a set of noises with different exposed time and requested to judge spontaneously on a 100-unipolar scale. To be concrete, the subjects were exposed to noises being varied in time from 15 sec up to max. 1,200 sec for the controlled traffic noise sources. So far achieved from laborious tests, it has an importance being on the logarithmic relations of perceived loudness and exposed time, say, it is more increased the perceived loudness in the sorter exposed time than in the longer exposed time. However, the trend is said to be not effective for the case of annoyance. On the other hand, the subjective impressions on relative annoyance of noise is shown to be correlated with the noise characteristics such as loudness (sones), tonality and time with logarithmic scale, the product correlation moment being calculated as $R^{2}=0.99$. The variances to be explained for annoyance assessments through varying the time of exposure were ranged between 30 % and 50% for the exposed time, $27{\sim}37%$ for tonality, and $34{\sim}20%$ for loudness, respectively With these results, hopefully, it can be helpful for those who want to work out an experimental design for evaluating an environmental noise or to quantify any psychological dimensions found in annoyance assessments.

• The Journal of the Acoustical Society of Korea
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• v.19 no.5
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• pp.65-70
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• 2000

It is blown that the loudness is one of the most important metrics in assessing the sound quality and a calculation method for loudness has been standardized for steady sounds. In this study, a new loudness model is suggested for dealing with the transient sound for a unified analysis of various practical sounds. A signal processing technique is introduced for this purpose, which is required for the band subdivision and the prediction of band-level change of transient sounds. In addition, models for the post-masking and the temporal integration are adopted in the analysis of the loudness of transient sounds. In order to solve the problem of the conventional loudness model in the pure-tone signal processing, a critical band filter is employed in the analysis, which consists of 47 critical filters having a filter spacing of a half of the critical bandwidth. For testing the effectiveness of the present model, the predicted responses are compared with the experimental data and it is observed that they are in good agreements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.330-331
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• 2010

In this paper, BSR noise from an instrument panel of a vehicle are investigated with integrated experimental methods. First, potential source regions of the instrument panel for BSR are localized by using the module-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR nosie from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.7
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• pp.644-650
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• 2010

Among various elements to affect customer's evaluation of vehicle quality, BSR(Buzz, Squeak, Rattle) are considered to be a mostly contributing factor. In this paper, we provide the test method which can be used to reduce the BSR noise of instrument panel in a vehicle. First, potential source regions of the instrument panel for BSR are localized by using the vibration-excitor and near-acoustic field visualization system. Then, subjective evaluation of BSR noise from the detected potential noise source regions is made with the Zwicker's loudness and time-varying loudness methods. This illustrative analysis reveals that current experimental methods can be used as a test procedure to systematically tackle BSR issues in early stage of the vehicle development cycle, which can result in the reduction of the production cost.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06c
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• pp.279-282
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• 1998

본 연구에서는 기존의 문헌에 자세히 기술되지 않은 주파수 분할 방법에 대한 고찰을 통해 과도음의 라우드니스 해석에 적합한 임계 대역 해석 방법을 제안하고, 이를 근거로 과도음의 라우드니스 모델을 구현하여 기존의 임상 실험 결과와의 비교함으로써 그 유효성을 확인하였다. 또한 순음의 라우드니스 해석에서 기존 라우드니스 모델이 안고 있는 신호해석 상의 문제점 등을 지적하고 이를 개선한 새로운 모델을 제시하였다. 개선 방법으로서 임계 대역폭의 1/2 간격으로 총 47개의 임계 대역 필터를 배치하여 필터의 경계에 순음이 존재할 때 발생할 수 있는 라우드니스 오차를 최소화 하였다. 또한 이 모델에서는 Zwicker가 제안했던 기존의 방법을 제안된 임계 대역 필터에 적합하도록 수정하는 작업이 포함되었다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1459-1464
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• 2006

In the previous studies on railway noise analysis, the main purpose of noise analysis is concerned with the reduction of A-weighted sound pressure level in order to satisfy noise regulations. However, more important facts on noise reduction are the subjective feelings of the human being on noise because people might be annoyed from the noise caused by train. In this paper, railway noise from different type of train are compared using the calculation of sound quality metrics with using strength related method that is calculation of A-weighted sound pressure level.