• 음성과학
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• 제9권1호
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• pp.77-88
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• 2002

Acoustical correlates of stress can be classified as duration, intensity and fundamental frequency. This study examined the acoustical differences in the first two syllables of stressed English words produced by ten American and Korean speakers. The Korean subjects scored very high on the TOEFL. They read at a normal speed a fable from which the acoustical parameters of eight words were analyzed. In order to make the data comparison meaningful, each parameter was collected at 100 dynamic time points proportional to the total duration of the two syllables. Then the ratio of the parameter sum of the first rime to that of the second rime was calculated to determine the relative prominence of the syllables. Results showed that the durations of the first two syllables were almost comparable between the Americans and Koreans. However, statistically significant differences showed up in the diphthong pronunciations and in the words with the second syllable stressed. Also, remarkably high r-squared values were found between pairs of the three acoustical parameters, which suggests that either one or a combination of two or more parameters may account for the prominence of a syllable within a word.

• 산업기술연구
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• 제41권1호
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• pp.15-20
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• 2021

This work proposes a simple method to use the added absorption per person values to predict the expected values of the acoustical conditions in occupied classrooms. This method is based on the effects of the values of added absorption per person on the unoccupied total absorption values of the classrooms and on other room acoustical parameters. The total sound absorption in an unoccupied classroom can be calculated from measured reverberation times in the classroom. The expected occupied absorption can be calculated using equation which was obtained in a previous study (Choi, 2017) by fitting a linear regression line to a plot of total occupied absorption versus the corresponding unoccupied total absorption values measured in 12 university classrooms. The ratios of occupied-to-unoccupied sound absorption are used to predict increments in the values of acoustical parameters that result when occupants are added to the rooms.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.975-978
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• 2007

This paper investigates stage acoustics in concert halls for ensemble performance in terms of stage support parameters. A concert hall with large stage area was selected. Objective measurements were carried out according to Gade's methods for investigating stage support (ST1). The sound field on the stage was evaluated using stage and audience acoustical parameters. According to the positions at stage, different acoustical characteristics were found. Higher ST1 and lower $IACC_{E3}$ were measured near side and rear stage walls. In case of conductor/soloist vs. orchestra player, objective measurement of acoustical parameters shows that early sound fields depend on the source-receiver distance but late sound fields depend on the location of side and rear walls. In addition, in-situ evaluation of the trio instrumentalists was carried out. Results show that ensemble is favored by higher early reflection of sounds and sound diffusion affecting ‘blending’ of their performance.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.722-727
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• 1994

In two previous papers [1], [2], we presented the validity of a method that calculated the Leq values along High Speed Train (TGV in french) lines from the level/time evolution of moving trains. Tanks to this method, it is now possible to compute specific time-related effects such as interactions between train bodies and close obstacles. This paper lists important parameters to be considered within TGV studies and presents the various levels of study, starting from the research of the best traject (extensive studies), passing through noise impact studies (intensive studies) of the chosen traject to the dimensionning of antinoise devices (final design), and all this to guarantee precise respect of noise criteria. A theoretical comparison study conducted on about 80 different types of antinoise devices including earthberms and noise barriers of different forms, dimensions and materials is also presented. At last a "final design" study using all benefits of the method (full 3D and time representation) is presented.presented.

• 한국음향학회지
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• 제24권2호
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• pp.111-116
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• 2005

본 연구는 주관적 음향평가를 통하여 콘서트 홀에서 선호되는 음향특성과 중요한 음향지표 조사에 그 목적이 있다. 호주의 두 콘서트 홀 (이하 Hall A와 Hall B로 가칭함)에서 더미헤드 (Dummy Head)로 녹음된 음악을 이용하여 음향평가를 위한 청감실험을 통해 실시하였다. 평가된 두 콘서트 홀의 음향선호도는 측정된 음향지표와의 상관도를 분석하여 실제 홀에서의 음향평가에 기여하는 음향지표를 조사하였다. 청감실험에서 피험자들은 Hall B가 Hall A에 비해 음향적으로 우수하다는 결과를 보여주었으며, Hall A의 낮은 음향선호도는 전문음악가와의 인터뷰조사결과와 유사하였다. 두 콘서트 홀의 음향평가에 가장 중요한 음향지표는 음압레벨로 밝혀졌다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 추계학술대회논문집
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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.

• 한국음향학회지
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• 제37권5호
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• pp.343-348
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• 2018

본 연구에서는 대학 강의실에서 공석 시 음향지표를 이용하여 만석 시 강의실의 음향지표를 예측하는 방법을 제시하였다. 먼저 공석 시 측정한 강의실의 $T_{30}$값으로 공석 시 실의 총 흡음력을 계산할 수 있다. 선행연구(Choi, 2016)에서 제시한 12개 강의실의 공석 시 총 흡음력에 대한 만석 시 총 흡음력의 선형 회귀식을 이용하여 만석 시 실의 총 흡음력을 예측할 수 있다. 공석 시에 대한 만석 시의 총 흡음력 비를 토대로 재실자의 부가흡음에 의한 강의실의 음향지표 변화폭을 예측할 수 있다. 이 예측방법을 이용하여 공석 시 실의 음향지표 값을 알면 비슷한 규모의 만석 시 강의실의 음향상태의 예측이 가능하다.

• 대한음성학회지:말소리
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• 제55권
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• pp.119-130
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• 2005

The aim of this paper is to investigate some acoustical characteristics of the voice quality features from the emotional speech database. Six different parameters are measured and compared for 6 different emotions (normal, happiness, sadness, fear, anger, boredom) and from 6 different speakers. Inter-speaker variability and intra-speaker variability are measured. Some intra-speaker consistency of the parameter change across the emotions are observed, but inter-speaker consistency are not observed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.666-670
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• 2006

It has been considered that scattered sounds have a positive effect on a hearing impression of a sound filed. This study investigates the degree and the quality of a scattered sound field by using the acoustical parameters and autocorrelation function(ACF) of impulse responses. The acoustical parameters and fine structure of the ACF of an impulse response were used for the evaluation of the scattered sound field. The relationship between the scattering coefficient of surfaces with various hemisphere diffuser configurations and the acoustical parameters and ACF parameters of impulse responses was investigated.

• The Journal of the Acoustical Society of Korea
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• 제24권3E호
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• pp.90-98
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• 2005

Enhanced approach using computational and experimental method is proposed and performed to describe very well the behavior of loudspeaker than conventional method. Proposed procedure is composed of four parts. First, Thiele-Small parameters for test loudspeaker are identified by an electrical impedance method like as a delta mass method. Second part includes the processes to measure physical properties. Physical data like masses and thicknesses of loudspeaker's components are measured by an electrical precision scale and a digital vernier caliper. Third, the identified Thiele-Small parameters are proposed to be used as load boundary conditions for vibration analysis instead of electromagnetic circuit analysis to get a driving force upon bobbin part. Also, these parameters and physical data are used to modify physical properties required for computation to accommodate simulated sound pressure level with measured one for loudspeaker enclosure system. These data like as Young's modulus and thickness for a diaphragm are required for vibration analysis of loudspeaker but not measured accurately. Finally, it was investigated that simulated sound pressure level with full acoustic modeling including an acoustic port for test loudspeaker agreed with experimental result very well in the midrange frequency band(from 100 Hz to 2,000 Hz). In addition, several design parametric study is performed to grasp acoustical behaviors of loudspeaker system due to variations of diaphragm thicknesses and shapes of dust cap.