• Title/Summary/Keyword: 음향성능 측정

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A Real-time Performance Evaluation System for Speech Waveform Coders (음성파형 부호화기의 실시간 성능측정 시스템)

  • 김용철;은종관
    • The Journal of the Acoustical Society of Korea
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    • v.3 no.1
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    • pp.43-54
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    • 1984
  • 본 논문에서는 음성파형 부호화기의 성능을 실시간 측정하기 위한 시스템의 구현에 관하여 연구 하였다. 본 장비는 "bit slice" 마이크로프로세서로 설계되었다. 개발된 시스템으로 세 개의 codec의 성능 을 측정하였으며 이 결과를 distortion analyzer로 측정한 결과와 비교하였다. 개발된 장비는 음성 부호 화기의 성능시험을 위한 주관적 청취시험 과정을 피할 수 있게 되었다.

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Comparison of the acoustical performance of auditoria by shapes using acoustic simulation and listening tests (시뮬레이션과 청감실험을 통한 공연장 형태별 음향성능 비교분석)

  • Chanwoo Kang;Chan-Hoon Haan
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.3
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    • pp.189-202
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    • 2023
  • In this study, the acoustic performance was analyzed by architectural shapes of the hall. There are four architectural shapes of halls. They are rectangular, horseshoe, surround, and fan-shape. Eight acoustic parameters were used to determine the acoustic performance. These are RT60, EDT, C80, BQI, LF, Gmid, G125 and ITDG. First, measurement data of famous concert halls around the world were analyzed. The correlation coefficient R was obtained by regression analysis of the relationship between the subjective ranking of the halls and the acoustic parameters. It was found that BQI, G, and ITDG have higher correlation coefficients R. Also the average of acoustic parameters for each architectural shape were obtained. The total acoustic performance for each shape was calculated by using the correlation coefficient R as a weight for each acoustic parameters. As a result, rectangular halls and horseshoe halls showed good acoustical performances. Second, 3D models of each architectural shape were created and acoustic simulation had been performed. The simulation was performed by creating 3D models of each four shapes of concert halls with the same volume and sound absorption coefficient. Listening test was carried out using the sound source which is created from impulse responses of 3D model. As a result, rectangular hall and horseshoe hall showed the best performance however surround hall and fan-shaped hall showed relatively poor performance.

Estimation of Wide-Band Acoustic Measurement Accuracy Based on Confidence as Variation of Signal-to-Noise Ratio (신호대잡음비에 따른 신뢰도 기반의 광대역 음향측정 정확도 예측)

  • 도경철;최재용;손경식
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.8
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    • pp.93-97
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    • 1998
  • 미지신호에 대한 측정에서는 오차분산의 명확한 표현이 어렵다. 본 연구에서는 이와 같은 수동측정에서의 측정정확도를 예측하기 위한 방법을 정립한다. 제안된 예측 방법은 신 뢰도를 기반으로 신호대잡음비 및 주파수대역폭과 시간적분과의 곱에 의해 정확도를 표현한 다. 본 논문에서는 배경소음 환경에서의 측정음향을 그대로 분석하는 경우와 배경소음을 예 측하여 측정음향에서 제거시키는 경우를 구분하여 광대역 음향측정시의 성능예측 기준을 시 뮬레이션하고 정확도를 예측한다.

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Properties estimation of acoustical material (음향재료의 물리적 성질 추정)

  • Kim Yoon Jae;Kang Yeon June
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.195-198
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    • 2004
  • 음향재료의 성능을 예측하기 위해서는 음향재료의 여러 물성들을 알아야 한다. 그러나 음향재료의 물성들을 측정하는 것은 매우 시간이 오래 걸리며, 복잡한 작업이다. 실제로 비틀림률이나 특성길이들은 정확하게 측정하기가 상당히 까다롭고 어렵다. 음향재료 각각의 물성들이 흠음률과 표면임피던스에 미치는 영향을 파악하고 임피던스 튜브에서 측정한 수직입사 흠음률을 이용하여 물성들을 추정하였다. 추정된 물성과 실험을 통하여 얻어진 음향재료의 물성을 비교하고, 추정된 물성들을 토대로 음향학적으로 모델링된 이론식으로 예측된 흡음률과 임피던스 튜브를 이용하여 측정한 흠음률을 비교하여 타당성을 검토하였다.

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Improvement and Change of Acoustic Performance of University Small Hall Remodeled as Exclusive for Lecture Room : Based on the case of the W University (강의전용 공간으로 리모델링된 대학 소공연장의 음향성능 개선 및 변화 : W대학의 사례를 바탕으로)

  • Kim, Min-Ju;Kim, Jae-Soo
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.19 no.2
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    • pp.21-31
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    • 2020
  • The purpose of this study was to analyze the contents of the sound environment among the various environmental factors that directly or indirectly affect the quality of education through the remodeling of the small hall of the College of Humanities at W University. Before remodeling into a lecture room, the small hall of the College of Humanities at W University, which is the subject of this study, was designed to create an indoor sound environment suitable for a lecture room by recognizing differences in acoustic performance between the performance halls that require adequate sound quality and the lecture rooms where the clarity of voice is important. Therefore, this study aimed to present examples of improved acoustic performance in lecture rooms by remodeling through the stages of measuring acoustic performance before remodeling, presentation of a change in finishing materials through sound simulation, and measurement of sound performance after remodeling. It is expected that this process can be used as an example of securing indoor acoustic performance suitable for educational space, such as lecture rooms, by changing the finishing materials.

Analysis of Measurement Accuracy Based on Confidences for Narrow-Band Underwater Acoustic Measurement (협대역 수중음향측정을 위한 신뢰도 기반의 측정정확도 분석)

  • 도경철;최재용;이용곤
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.4
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    • pp.16-22
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    • 2000
  • In order to predict the performance and the usefulness of the narrow-band underwater acoustic measurement system at design stage, whose error variance is not clearly described, in this study a boundary equation to estimate the measurement accuracy is proposed based on the confidency as SNR variation. The boundary is presented as a function of SNR and the number of samples. In this paper, the measurement performance for narrow-band signal is simulated by the proposed boundary equation and the results are reviewed in the biased noise condition and separately in the background noise rejected condition.

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Measurement of Transmission Loss Using Surface Intensity Method in Building Elements (표면 인텐시티법을 이용한 건물부위의 음향투과손실 측정)

  • Kim, Heung-Sik;Son, Jang-Yeol;O, Jae-Eung
    • The Journal of the Acoustical Society of Korea
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    • v.6 no.3
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    • pp.17-22
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    • 1987
  • This study is to propose more reliable test method in evaluating the sound insulation performance of building element in fields. This method involves the measurements of the incident acoustic intensity and transmitted surface intensity. The incident intensity is determined from measurements of the space averaged sound pressure level in source room. The transmitted surface intensity is measured directly using one microphone and one accelerometer. The results of experiments indicate that this new method makes it possible to give more reliable data than the conventional field test method. The values of trans-mission loss measured by this new method are compared favorably with those obtained using the sound intensity method and theoretical calculation(mass law).

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Evaluation and analysis of the acoustic performance of ducted silencers based on ISO 7235 (공조용 소음기의 성능시험 평가 및 분석 (ISO 7235))

  • Kim, Doo-Hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.191-196
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    • 2000
  • 본 논문에서는 공조용 소음기에 대한 삽입손실 및 압력손실과 같은 음향성능 평가를 위해 필요한 제반 사항을 ISO 7235에 근거하여 소개하였다. 이를 위해 시험설비의 종류 및 구비조건, 측정방법, 측정시 유의사항 등을 기술하였고, 이로서 공조용 소음기의 보다 정확한 음향성능평가가 이루어지도록 검토 하였다.

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Comparison of acoustics performance measurement and evaluation standard of office space and office acoustics criteria of European countries (사무공간의 음향성능 측정, 평가 방법의 표준화와 유럽 국가들의 음향성능 기준 비교)

  • Jeong-Ho Jeong
    • The Journal of the Acoustical Society of Korea
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    • v.42 no.2
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    • pp.133-142
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    • 2023
  • The office environment is changing according to work types, Information Technology (IT) advancements, and the Coronavirus disease (COVID)-19 situation. In order for office space users to perform their tasks comfortably and efficiently, it is necessary to secure individual privacy as well as easy communication among members. In Korea, the demand for improving the acoustic performance of office spaces is also increasing, but the related performance criteria and guidelines have not been established. In this study, standardization of office space acoustic performance measurement and evaluation methods and European countries' acoustic performance criteria were compared and reviewed. It is proposed to comprehensively review international standardization trends and acoustic performance standards in each country and to establish and utilize criteria for evaluating the acoustic performance and satisfaction of office spaces in Korea through our survey. Considering the international standardization direction and compatibility with communication and Public Address (PA) systems, it is appropriate to establish criteria using the speech transmission index or Speech Transmission Index (STI) application index. This criterion will be highly utilizable and compatible. In addition, since the office furniture industry is interested in improving the acoustic performance of office space, it is necessary to establish a labelling system for speech level reduction of office furniture.

A Study on the Acoustic Absorption Character of a Helmholtz Resonator in Model Chamber (모형연소실에 장착한 헬름홀츠 공명기의 흡음특성에 관한 연구)

  • Park, Ju-Hyun;Sohn, Chae-Hoon
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2009.11a
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    • pp.399-402
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    • 2009
  • Acoustic design parameters of a Helmholtz resonator are studied experimentally and numerically for acoustic stability in a model acoustic tube. According to standard acoustic-test procedures, acoustic-pressure signals are measured. Quantitative acoustic properties of sound absorption coefficient are evaluated and thereby, the acoustic damping capacity of the resonator is characterized. Helmholtz resonator on spring-damper system use were understanding for acoustic damping. The length of orifice and the volume of cavity of resonator are selected as design parameters for tuning of the resonator. Acoustic- damping capacity of the resonator increases with its cavity volume. And orifice length as increases with acoustic damping capacity was decreased.

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