• Title/Summary/Keyword: 잔향음

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A 3D Audio Broadcasting Terminal for Interactive Broadcasting Services (대화형 방송을 위한 3차원 오디오 방송단말)

  • Park Gi Yoon;Lee Taejin;Kang Kyeongok;Hong Jinwoo
    • Journal of Broadcast Engineering
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    • v.10 no.1 s.26
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    • pp.22-30
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    • 2005
  • We implement an interactive 3D audio broadcasting terminal which synthesizes an audio scene according to the request of a user. Audio scene structure is described by the MPEG-4 AudioBIFS specifications. The user updates scene attributes and the terminal synthesizes the corresponding sound images in the 3D space. The terminal supports the MPEG-4 Audio top nodes and some visual nodes. Instead of using sensor nodes and route elements, we predefine node type-specific user interfaces to support BIFS commands for field replacement. We employ sound spatialization, directivity/shape modeling, and reverberation effects for 3D audio rendering and realistic feedback to user inputs. We also introduce a virtual concert program as an application scenario of the interactive broadcasting terminal.

Acoustic design for the renovation of a cultural heritage building, SH high school auditorium (문화재로 지정된 SH고등학교 강당의 음향리노베이션설계 및 평가)

  • Jeong, Daeup;Oh, Yedam;Lee, Hyojin
    • The Journal of the Acoustical Society of Korea
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    • v.38 no.3
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    • pp.266-274
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    • 2019
  • As can be seen in the statistics on domestic performance facilities, small or large scale of acoustic renovations seem to be unavoidable in many of those facilities due to its senility. However it is hard to find case studies which can be referred to for its acoustic renovation process. This study tried to provide a case study example of acoustic renovation for a high school auditorium which has many restrictions as a cultural heritage building. Requirements from the client and acoustic problems found through a field measurement of existing space motivated acoustic design solutions and alternatives which can improve the acoustics of the space. The whole process from the initial stage of diagnosing acoustic problems to the final stage of a post acoustic evaluation after the completion of construction was described. The result from the post acoustic evaluation suggested that reverberation characteristics of the space as well as definition and clarity have been greatly improved by applying acoustic design solutions and alternatives. However, loudness of sounds in the space didn't reach the aimed level, which is due to the limited capability of slat ceiling structure for providing strong early reflections.

Investigation of the sound insulation performance of walls and flanking noises in classrooms using field measurements (현장실험을 통한 학교교실의 벽체 차음성능 및 측로전달소음 조사)

  • Ryu, Da-Jung;Park, Chan-Jae;Haan, Chan-Hoon
    • The Journal of the Acoustical Society of Korea
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    • v.36 no.5
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    • pp.329-337
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    • 2017
  • In USA and UK, the standards of both reverberation time and background noise level have been established for the appropriate aural environment in classrooms. In order to realize this, guidelines for architectural planning and interior finishing have been also suggested. However, in Korea, there has hardly been any guidelines for satisfying background noise criteria and investigation about sound insulation performance of current walls of classrooms. The present study investigates the structure of outer wall and walls between classrooms of two middle schools in order to analyze the sound insulation performance against both exterior and interior noises. Acoustic parameters including transmission loss, standardized sound level difference, and signal to noise ratio have been measured and analyzed for sound insulation performance of walls and flanking noises. As a result, concerning the walls in between classrooms, it was found that walls of dry construction have greater sound insulation performance rather than the walls of wet construction especially in mid and high frequency bands. Also, It was revealed that thermopane, insulated pair glass, of outer walls, has greater sound insulation performance than the double window consisted of two single pane glass. Regarding flanking noises, the standards were exceeded when all windows, or windows and doors front onto corridor were opened. It denotes that students could be disturbed with the sound transmission by the interior noises.

Improving target recognition of active sonar multi-layer processor through deep learning of a small amounts of imbalanced data (소수 불균형 데이터의 심층학습을 통한 능동소나 다층처리기의 표적 인식성 개선)

  • Young-Woo Ryu;Jeong-Goo Kim
    • The Journal of the Acoustical Society of Korea
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    • v.43 no.2
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    • pp.225-233
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    • 2024
  • Active sonar transmits sound waves to detect covertly maneuvering underwater objects and detects the signals reflected back from the target. However, in addition to the target's echo, the active sonar's received signal is mixed with seafloor, sea surface reverberation, biological noise, and other noise, making target recognition difficult. Conventional techniques for detecting signals above a threshold not only cause false detections or miss targets depending on the set threshold, but also have the problem of having to set an appropriate threshold for various underwater environments. To overcome this, research has been conducted on automatic calculation of threshold values through techniques such as Constant False Alarm Rate (CFAR) and application of advanced tracking filters and association techniques, but there are limitations in environments where a significant number of detections occur. As deep learning technology has recently developed, efforts have been made to apply it in the field of underwater target detection, but it is very difficult to acquire active sonar data for discriminator learning, so not only is the data rare, but there are only a very small number of targets and a relatively large number of non-targets. There are difficulties due to the imbalance of data. In this paper, the image of the energy distribution of the detection signal is used, and a classifier is learned in a way that takes into account the imbalance of the data to distinguish between targets and non-targets and added to the existing technique. Through the proposed technique, target misclassification was minimized and non-targets were eliminated, making target recognition easier for active sonar operators. And the effectiveness of the proposed technique was verified through sea experiment data obtained in the East Sea.