• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1279-1286
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• 2004

This paper continues companion paper, part I : measurement and analysis. As shown in companion Paper, information and energy in monaural signal is quite different from that of binaural signal. In this paper, difference between monaural and binaural signal of transportation noise are investigated in subjective response test. We executed hearing screening test before giving a subject response test and excluded subjects who had physical hearing loss. An annoyance response test was conducted using headphone to avoid cross-talk effect in binaural testing. Percentage of highly annoyed under binaural signal reproduction is higher than percentage of highly annoyed under monaural signal reproduction. Result implies binaural reproduction technique is proper for a study of human response to short-term noise exposure in a headphone simulated-environment.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.12
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• pp.1268-1278
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• 2004

Measurement of noise is not only to know the information of acoustic pressure but to assess human response to noise. To find human response to transportation noise through the laboratory study we have to measure and reproduce noise. The method of noise reproduction is largely divided into monaural and binaural techniques. But human fundamentally hears sound through both ears, referred as binaural hearing. Binaural signal is different from monaural signal because it includes more information of physical phenomena like acoustical reflection, diffraction and refraction. Especially head and pinna play an important role in perceiving change of signal origin. So, the amplitude of binaural signal is higher than that of monaural signal and spectrum of both signals is discriminated. Most of assessment and regulation of transportation noise are, however, based on monaural measurement techniques. The quantitative difference between monaural and binaural measurement is investigated in this study. Comparison on several transportation noisesshows defect of information in monaural measurements.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.720-724
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• 2007

Recently, in accordance with increase of the desire for Sports for All(Life Sports), the swimming pools in many areas are under construction. However, since they used many of the reflexible finish-materials on account of the characteristics of hydrophilic space, most of the Indoor Swimming Pools are generating the excessive reverberation. Such reverberation is bringing about the problem that obstructs the oral communication between the coach and the player, and the Clearness of Sound, besides the sport activity. On this viewpoint, on the object of the actually built indoor swimming pool, after the conduct of an optimized acoustics design by the remodeling through a computer simulation, and by carrying out the Psycho-Acoustics Experiment utilizing of Auralization Technique which is able to experience Virtual Sound Field at the stage of designing, then this thesis has attempted to appraise on the acoustic condition after the completion of construction. It is considered that such result of the study could be utilized as the useful data that enables to improve the curtailment effect of construction cost as well as the acoustic capability, by means of the presupposition control on the acoustic problem from the stage of design, for the occasion when the similar indoor swimming pool is planning to build, henceforth.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.623-627
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• 2007

In case of the Grand Performance Hall, in view of its distinctiveness, since various Assembly Activity as well as Lecture together with the use for Music are important besides the purpose of Performance itself, the consideration with regard to the sound environment which enables to minimize the acoustic defect has appeared on the stage as an essential factor. On this viewpoint, this Study has attempted to examine the acoustic satisfaction degree and its response regarding to the grand performance hall by means of the measurement and valuation about the psychological volume of human-being using the auditory-evoked technology that possible to experience the Virtual Sound Field at the designing stage, after practice of the optimized acoustic design for the object of the grand performance hall on the step of construction. As the result of auditory-evocation, it was known that the valuation about the acoustic performance after reformation has been improved affirmatively than before reformation. It is considered that such outcome of the study could be utilized as the useful material that enables to improve the curtailment effect of construction cost and the acoustic performance, by means of the presupposition control about the acoustic problem from the stage of design, for the occasion when the similar Performance Hall is planning to build, hereafter.

• The Journal of the Acoustical Society of Korea
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• v.12 no.5
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• pp.38-46
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• 1993

스피커는 입력이 전기신호이고 출력이 소리인 전기 음향 장치로서, 고유의 전달함수를 갖는 하나의 시스템으로 생각할 수 있다. 일한 스피커 시스템의 전달함수는 여러 가지 원인으로 인해 주파수 영역에서 평탄한 특성을 가지지 못하며 선형위상의 조건을 만족시키기가 힘들다. 음색을 변화시키는 스피커의 전달함수를 선형이라고 가정할 때 스피커의 앞단에서 스피커의 선형 전달함수의 역에 해당하는 선형 필터를 추가함으로쏘, 음색의 왜곡은 보정할 수 있다. 본 연구에서는 이러한 스피커의 선형왜곡을 보상하기 위한 선형필터로서 FIR 필터를 사용하였으나, 2장에 제시되어 있는 기존의 알고리듬과는달리 귀의 청감특성을 이용하여 가청주파수 대역에 대해 몇 개의 대역으로 나눈 후, 각 대역마다 보상 할 주파수 해상도를 달리하는 새로운 알고리듬에 대해 기술하였다. 이러한 다해상도 선형왜곡 보상시스템은 각 대역마다 다른 해상도로 보상한다는점에서는 필터뱅크 보상 시스템과 유사하지만, 대역통과필터가 아닌 저역통과필터만을 이용하여 설계의 복잡서응ㄹ 줄였으며 각 대역마다 독립적으로 보상하는 필터뱅크 보상시스템과는 달리 1차 대역에서 보상하지 ath한 오차를 2차, 3차에서 보상하는 새로운 기법을 이용하였다. 본 알고리듬을 적용한 모의실험을 통하여 성능을 평가한 결과 가청음대역에서 ±6dB의 왜곡을 보인 스피커가 실효 tap수를 272로 했을 때 ±0.5dB의 리플을 보이는 양호한 결과를 얻었다.

• Journal of Broadcast Engineering
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• v.11 no.4 s.33
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• pp.448-457
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• 2006

HRTF DB, including the information of the sounds which is arrived to our ears, is generally used to make a 3D sound. But it can decline some three-dimensional effects by the confusion between front and back directions due to the non-individual HRTF depending on each listener. In this paper, we propose a new method to use psychoacoustic theory that reduces the confusion of sound image localization. And we make use of an excitation energy by the sense of hearing. This method is brought HRTF spectrum characteristics into relief to draw out the energy ratio about the bark band. Informal listening tests show that the proposed method improves the front-back sound localization characteristics much better than the conventional methods.

• The Journal of the Acoustical Society of Korea
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• v.12 no.3
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• pp.43-48
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• 1993

This study was carried out to verificate the possibility of using the laboratory setting psycho-acoustic experiment compared with the field and to delineate the appropriate indices in evaluating the Noisiness of road traffic noise by means of psycho-acoustic method. Reviewing the typical patterns of traffic noises depending upon the shapes ad conditions of the road, the road traffic noises in several representative points in the major residential areas in Kwangju city were recorded and reproduced with the noise levels modified in various steps. With these 20 sound sources, psycho-acoustic experiments in the laboratory were performed on 11 volunteer subjects. And then, psycho-acoustic experiments in the real field were performed on 10 volunteer subjects to compare the results of the laboratory experiment, the results are summerized as follows : 1. The psycho-acoustic experiments in the laboratory elicited the data well matching with those obtained in the field, resulting in even higher corelation levels. This indicates that the field assessement of responses to the noise can be replaced by the evaluatioin in the laboratory settings which render many variables easily controlled and that the responses of the residents to the noise can be easily predicted in the laboratory by applying this method. 2. Also among the complex indices, such as Noise Pollution Level or Annoyance Index high correlations were detected. On the other hand, low corelations were noted among Traffic Noise Index. 3. Highly significant correlations were found among the direct indices such as Leq, L\sub 10\, On the other hand, low correlations were detected among L\sub 50\.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.8
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• pp.708-719
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• 2007

In case of indoor gymnastics training floor, in view of its characteristics, since it is simultaneously required the related smooth communication between the coach and the player, also the acoustic performance regarding to the clearness of music, besides the sport activity, the consideration about the acoustic character has entered the stage as an indispensable element. On such viewpoint, recently constructed dome-typed gymnastic training floor was optimized acoustic design with remodeling through acoustic simulation test. And acoustic satisfaction degree and reaction was attempted to investigate about the gymnastics training floor estimating value of human's psychological(sensual) degree using auralization that enables to experience the virtual sound field at the stage of design. As the result of investigation about the research on the space of object, it could be known that the valuation regarding to the acoustic performance of 'after-improvement' was distinctly more refined than that of 'before-improvement'. It is now considering that such result of the study can be utilized as the useful data which enables to improve the retrenchment effect of the construction cost as well as the acoustic capability, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1
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• pp.73-77
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• 2000

It is necessary to express and evaluate annoyances, caused by noises, as a comparable quantity for establishing an efficient, economic and user-oriented noise control plan. In particular, cares should be taken for impact noises, since their dynamic properties are different from those of steady-state noises. A series of preliminary experiments were carried out to quantify the annoyances caused by floor impact noises. Results suggests that the characteristics of an impact source was more important factor than the properties of a floor structure for determining loudness and noisiness of subjects. Also, the heavy impact source was found to be felt louder and noisier by 5-6dB than the light impact source.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.917-917
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• 2003

The auditory experiments based on the subjective annoyance responses were undertaken for the establishment of the adverb modifiers of the heavy-weight impact noises. The standard heavy weight impact noise, impact ball noise and adult walking noise were recorded by dummy head at a newly-built apartment and were presented to the subjects by headphones. The levels of the three impact noises were varied from 30 to 60㏈(A) and the subjects matched one of the adverb modifiers to each level of the noise sources. As a result, seven scale modifiers were established and the intervals between the modifiers were found as equal. In addition, it was found that the lower annoyance noise limits for the heavyweight impact, impact ball and walking were 40-45㏈ (L$\sub$I, Fmax. AW), which is 6㏈ lower than in the previous study. The background noise level was as low as 21㏈(A) in the test booth, therefore, the testing conditions need to be concerned for evaluation of floor impact noise.