• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.626-630
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• 2006

This study investigates the effects of Interaural Cross-correlation(IACC) and its variation on annoyance of the heavy-weight impact sounds. Subjects evaluated the annoyance of the heavy-weight floor impact sounds recorded in rooms of apartments which have different sound insulation treatments; furnished and occupied conditions are characterized by the ACF/IACF factors. A paired comparison test was conducted using the impact sound sources whose IACC and variation of IACC values were different. It was found that IACC is inversely correlated with the scale value(r=-0.62) whereas the variation of IACC is not(r=-0.34). On the contrary, ${\Phi}(0)$ is highly correlated with scale value of annoyance and ${\Phi}(0)$ is need to be controlled as constant to find the effect of IACC on annoyance.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.287-290
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• 2007

In this study, the effect of temporal variation of IACC on subjective response to heavy-weight floor impact noise generated by impact ball was investigated. Subjective evaluation was conducted to investigate the effect of temporal variation of IACC on perception of heavy-weight floor impact noise using paired comparison test. The results showed that the effects of SPL and temporal variation of IACC on the annoyance of heavy-weight impact noises were independent and the contribution of SPL was much larger than that of temporal variation of IACC. It was also found that the effect of IACC is larger than temporal variation of IACC comparing to previous study.

• The Journal of the Acoustical Society of Korea
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• v.11 no.1E
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• pp.64-72
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• 1992

본 연구는 음장의 주관 확산감과 관련있는 두 귀에 입사하는 신호의 상호상관도와 청각유발 반 응과의 관계를 밝히기 위한 것이다. 실험은 중신 주파수가 500Hz인 1/3옥타브 대역잡음을 이용하여 IACC를 0.95에서 0.1까지 가변시키면서 AER을 기록하였다. IACC와 주관확산감과의 함수 결과와 비교 하기 위하여 기준음과 테스트음의 쌍을 교대로 제시하면서 AER을 청각 부위에서 기록하였다. 그 결과 테스트음에 대해 IACC와 관련된 정보는 AER의 반응시간에 나타났고, IACC의 크기가 감소함에 따라 반응시간이 길어지는 경향이 나타났다. 여기에서 IACC와 AER의 반응시간과는 선형관계를 나타냈다. 이 결과는 청각계에서 음장의 IACCDP 반응하는 뉴런이나 메카니즘이 존재하는 것을 암시하고 있음을 알 수 있다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.960-963
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• 2007

The effect of spatial factors on subjective responses to heavy-weight floor impact noise was investigated. Heavy-weight impact noises were generated and recorded in several apartments and a testing building using impact ball and binaural microphone to measure IACC of the noises. Just noticeable differences (JNDs) of IACC and SPL of heavy-weight impact noise were also investigated. Auditory experiments were conducted using method of limit. It was found that the JNDs of IACC and SPL were 0.12 and 1.5dB, respectively. Contribution of IACC and SPL to annoyance of heavy-weight floor impact noise is being further investigated.

• The Journal of the Acoustical Society of Korea
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• v.42 no.4
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• pp.285-297
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• 2023

The present study aims to investigate the acoustic performance of the creative convergence classrooms in Korea used by elementary school students under the age of 9 introduced through the school space innovation project. In order to do this, acoustic performances of three creative convergence classrooms were measured. The measured acoustic parameters were background noise levels, Reverberation Time (RT), D₅₀, Speech Transmission Index (STI), and Inter-Aural Cross Correlation (IACC). Also, acoustic parameters including Transmission Loss (TL) and standardized level difference (D_nT) have been measured for the analysis of sound insulation performance of walls. In addition, the noise level was measured according to the opening conditions of doors and windows in the classroom. As a result, background noise level was measured at an average of 28.0 dB(A) to 32.8 dB(A) when the air conditioner was not operated, and the RT did not exceed 0.6 s. There were differences in IACC according to various desk layouts, and IACC values were high in the center line and the seats near the sound source. In particular, higher IACC was measured at the seats on the center line facing the source squarely. Regarding noise level in the classroom according to the opening conditions of doors and windows, the standards were exceeded when all windows, or windows and doors front onto the corridor were opened.

• Proceedings of the Acoustical Society of Korea Conference
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• spring
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• pp.443-446
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• 2000

본 연구는 과학적이고 실험적인 접근을 통하여 공간의 비례와 실내음향과의 상관관계를 규명하기 위하여 체적과 마감재료가 같고 비슷한 기본축척의 모델을 중심으로 가로, 세로, 높이의 비율이 다른 4개의 모델에서 각각 SPL, EDT, C, RT, LEF, IACC 등을 측정하여 각 형태의 모델의 값을 비교 분석하였다. 실험결과 잔향은 동일한 체적인 경우 음원으로부터 평균거리가 멀리 위치한 장방형의 형태가 양쪽 측벽 사이의 거리가 넓은 장방형보다 잔향시간이 긴 것으로 나타났다. 음압은 실의 체적이 작고 음원으로부터의 평균거리가 짧은 순서로 큰 반면, 명료도는 잔향의 크기순서에 반대로 분석되었으며 특히 음원으로부터의 직선거리가 짧은 순서로 명료도가 좋게 나타났다. IACC는 양쪽 측벽의 거리가 가장 긴 모델에서 가장 작게 나타났다 그러나, 초기 음장에서는 그 변화가 작게 나타났는데 이것은 IACC가 실의 형태에 장시간 관여하는 지수라는 것을 의미한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.772-777
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• 2004

Opera house acoustics were subjectively evaluated in order to investigate the effect of performance stage views on the audience's perception of the seat acoustics in an opera house. Nine seats from an existing opera house were selected for the auditory and/or visual experiments according to seating area distribution and acoustical parameters such as RT and $1-IACC_{E3}$. The recorded music, convolved from the impulse response, was presented with and without visual images of the stage. Subjects were asked to assess the auditory/visual descriptors and overall impression of the music at each seat. The results showed that good visual input helps produce a favorable impression of the acoustics, but a limited view degrades acoustical impression. The acoustical parameters in the tested seats were also investigated to find the relationship between the acoustical parameters and the visual/sound impression.

• Journal of the Korean Institute of Educational Facilities
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• v.28 no.3
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• pp.3-14
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• 2021

Speech information of teachers is transmitted to students in classrooms so that appropriate aural environment should be provided for academic purposes. Many researches have been undertaken for classroom acoustics, and acoustic standards of domestic classrooms were suggested based on the reverberation time and background noise level. However, these standards are suitable for middle and high schools and so not consider the auditory ability by ages. As a precedent research, the present study was begun to suggest an acoustic standard for lower grade elementary school classrooms with children under age 9 who have not normal auditory ability. In order to do this, acoustic performances of the lower grade classrooms were measured and compared with the general classrooms. Also, change of acoustic parameters depending on the desk layout was measured and analyzed. The measured acoustic parameters were background noise, signal to noise ratio, RT, STI, D₅₀, and IACC. As a result, it was found that background noise is exceed the standard of 35dB(A) at the schools along the road sides. Also, it was shown that most of acoustic parameters are higher in the classrooms built recently rather than the old classrooms. Generally, there are not much difference of acoustic parameters among the various desk layouts but, better acoustic performances are acquired at the center line and the seats near sound source. Also, Higher IACC was measured at the seats on the center line facing the source squarely.

• The Journal of the Acoustical Society of Korea
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• v.24 no.2
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• pp.103-110
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• 2005

Providing adequate amount of spatial impression for spaciousness) has been known to be one of the most important design considerations for the good acoustics of rooms for music. and the measurement, of room acoustics using parameters. such as LEF and IACC, forms an essential part of such evaluation. However. it is unavoidable to use different transducers (figure of eight microphones. head and torso) for the measurement of each parameter and it tends to make the measurement procedure complicated. The Present work tried to provide a simpler way to measure these binaural room acoustic parameters including monaural ones with a single measurement system using both spatial information collected through a 5-channel microphone and a trained neural network. A computer simulation program, CATT-Acoustic V7.2. which allowed us to obtain exactly the same spatial information as a 5-channel microphone was used. since it requires quite a large amount of data for practical training of a neural network. Since each reflection has different energy. delay and direction, energy should be integrated properly. the concept of ray tracing method was applied inversely in this work. Also applying weightings according to the delay times was considered in this work. Finally, predicted results were compared with the measured data md their correlations were analyzed and discussed.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.451-454
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• 1999

서양음악의 연구는 음향학의 측면에서 수십년 동안 연구가 진행되어왔다. 이를 통해 콘서트홀의 음향학적 특성을 평가할 수 있는 객관적 지표들을 제시할 수 있었다. 하지만 국악에 있어서는 공연장에 대한 음향학적인 지표가 공식화된 것이 없고, 게다가 지표를 찾기 위한 충분한 국악전용 공연장의 수가 부족하다. 따라서 본 논문에서는 국립국악원 예악당의 모델을 기초로 한 컴퓨터 모의실험을 통해서 얻어진 가상 국악공연장을 바탕으로 RT, Warmth, IACC, ITDG 등의 4가지 지표를 가지고 각기 다양한 시료를 제작하여 청취실험을 실시하였다. 그 결과 서양음악과는 다른 경향의 RT, Warmth 선호도를 추출할 수 있었다.