• Title, Summary, Keyword: Sound characteristics

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The Selection of the Scenery and Sound as the Environmental Friendly Elements (친환경 요소로서의 경관과 그에 어울리는 소리의 선택)

  • Shin, Yong-Gyu;Jeon, Ji-Hyeon;Jang, Gil-Soo;Kook, Chan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.682-685
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    • 2005
  • In this research, how the evaluation of the spacial image influenced by the environmental friendly elements included in the visual information, and how the selection of the sound changed depending on the characteristics of spatial image by the 40 subjects were carried out. Vast tracts of green land and the waterfront were highly preferred and impressive than the other spaces. The green music, signal with water sound and bird chirping sound were highly scored. In the frequency characteristics of the factors, the first factor was artificial sound(high at the low frequency band), the second was natural sound(uniform at all frequency band) and the third was water sound(high at the middle and high frequency band over 500Hz). This shows that the proposal of the sound which has the frequency characteristics fit to the spacial image should be selected for the soundscape of the target space.

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Sound Radiation Characteristics of Cracked Rectangular Vibrating Plates (균열을 갖는 직사각형 진동평판의 음향 방사특성)

  • 김태진;이우식
    • Proceedings of the KSR Conference
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    • pp.119-124
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    • 2002
  • This paper considers the sound radiation characteristics of a craked rectangular vibrating plate, varying the orientation angle of a line crack. The vibration response of the cracked vibrating plate is obtained by using ANSYS, the acoustic theory based on the lumped parameter model is used to calculate radiated sound power. The radiated sound powers are computed with varying the orientation angle of the crack: i.e, 0$^{\circ}$, 45$^{\circ}$, and 90$^{\circ}$. It is found that characteristics of the radiated sound power are very closely related to the crack orientation, vibration mode and crack location.

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A Study on Reduction of Sound Noise Induced by Disk Rotation in Optical Disk Drives (광 디스크 드라이브의 공력소음 감소에 관한 연구)

  • 송인상;박건순;최학현;김수경;이승엽
    • Journal of KSNVE
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    • v.9 no.4
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    • pp.693-702
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    • 1999
  • We study the characteristics of airflow and sound noise induced by disk rotation in optical disk drives. The characteristics of airflow around a rotating disk surrounded by various tray structures are numerically investigated using a commercial CFD program and then compared with experimental results. Sound pressure and intensity caused by the fluid-structure interactions in the CD/DVD-ROM drive are measured, and the effect of the ariflow on the sound noise and disk vibration is discussed. In order to reduce airflow-induced noise and vibration around the rotating disk, tray geometry is modified. Both numerical and experimental studies implemented with different tray models show that the improved tray model alters the characteristics of the disk-induced airflow, causing the reduction of the airflow-induced sound level.

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Experimental study of the sound quality performance and improvement of magnetic fluid speaker (자성유체 스피커의 음질 성능 및 향상에 관한 실험적 연구)

  • Lee, Moo-Yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.12
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    • pp.6993-6997
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    • 2014
  • The aim of this study was to experimentally investigate the sound quality characteristics, such as sound deflection, sound pressure level and frequency characteristics of a magnetic type speaker in an anechoic chamber to overcome the sound quality and voice-coil temperature problems. To accomplish this, the sound quality performance of the magnetic type speaker was tested according to the magnetic fluid amount and magnetic field intensity. The sound deflection, sound pressure level, and frequency characteristics were measured using the Smarrt program. As a result, at a magnetic fluid amount of 2.4 ml, the sound deflection and the sound pressure level of the magnetic type speaker were enhanced by comparing with those of the general type speaker. The frequency characteristics and the sound pressure level of the magnetic type speaker were enhanced greatly with increasing magnetic field intensity from 8.06 mT to 9.10 mT. In addition, the sound deflection of the magnetic type speaker was 0.01% lower than that of the general type speaker.

A Study on Noise Identification of Compressor Based on Two Dimensional Complex Sound Intensity (Two Dimensional Complex Sound Intensity를 이용한 압축기 소음원 규명에 관한 연구)

  • 안병하;김영수
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.1
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    • pp.83-92
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    • 2000
  • Sound intensity method is well known as a visualization technique of sound field or sound propagation in noise control. Sound intensity or energy flux is a vector quantity which describes the amount and the direction of net flow of acoustic energy at a given position. Especially two dimensional sound intensity method is very useful in evaluating periodic characteristics and acoustic propagation mode of noise source. In this paper, we have studied the noise source Identification, acoustic sound field analysis, and characteristics of noise source of rotary compressor and scroll compressor for air conditioner using complex sound intensity method. Also we proposed a now method of time domain analysis which is used in evaluating of position of noise source in rotary and scroll compressor in this paper This paper presents the advantage, simplicity and economical efficiency of this method by analysing the characteristics of noise source with two dimensional complex sound intensity simultaneously.

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Effect of surface etching and ultrafine fibers on sound absorption characteristics

  • Lee, Yun-Eung;Seon, Choe-Hwa;Su, Baek-Mun;Hwan, Ju-Chang
    • Proceedings of the Korean Fiber Society Conference
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    • pp.406-409
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    • 1998
  • Sound absorbing materials are divided into several types according to the appearances and the characteristics. Basic mechanism of sound absorption in various sound absorbing materials is the conversion of sound energy into hat energy. Here the important elements which govern by the conversion from sound into heat depend on the type of materials. (omitted)

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Sound Radiation Characteristics of A Cracked Rectangular Vibrating Plate (균열을 갖는 직사각형 진동평판의 음향 방사특성)

  • 김태진;박종환;이우식
    • Journal of the Korean Society for Railway
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    • v.6 no.3
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    • pp.163-168
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    • 2003
  • This paper considers the sound radiation characteristics of a cracked rectangular vibrating plate, varying the orientation angle of a line crack. The vibration response of the cracked vibrating plate is obtained by using ANSYS, the acoustic theory based on the lumped parameter model is used to calculate radiated sound power. The radiated sound powers are computed with varying the orientation angle of the crack: i.e, 0$^{\circ}$, 45$^{\circ}$, and 90$^{\circ}$. It is found that characteristics of the radiated sound power are very closely related to the crack orientation, vibration mode and crack location.

A Multivariate Analysis of Variance Applied to the Subjective Test of the Sound Quality of the Car Audio (차량 음향 시스템의 음질평가를 위한 다변량 분산분석)

  • Choi, Kyung-Mee;Doo, Se-Jin
    • The Korean Journal of Applied Statistics
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    • v.20 no.3
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    • pp.475-485
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    • 2007
  • In this work we measured and analyzed the subjective opinions of consumers towards the sound quality of car audios through a questionnaire. First of all, we chose eight controllable factors which had been known to affect the quality of reproduced sound. An orthogonal design of experiments was used to imitate the objective sound environments by reproducing the combinations of 8 sound characteristics, each with two levels. Then we defined 8 corresponding response variables to measure the subjective opinions towards the quality of reproduced sound. Finally, we applied the Multivariate Analysis of Valiance to explore the significant sound characteristics which affected the subjective opinions towards the quality of reproduced sound.

Sound Quality Index Development of Electrically Powered Vehicle Roller Blind (차량용 전동 롤러 블라인드의 음질지수 개발)

  • Sung, Weonchan;Jo, Hyeonho;Kim, Seonghyeon;Park, Dongchul;Kang, Yeonjune
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.785-790
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    • 2014
  • The purpose of this study is to identify the significant sound quality metric and compose the sound quality index of motor driven roller blind which is part of vehicle sunroof. Before subjective evaluation, sound characteristics of roller blind was analyzed and set the target operating sound for subjective evaluation. Thus, transfer sound of roller blind which has the characteristics of sound modulation was used for subjective evaluation. Linear regression was carried out by chosen Zwicker's metrics which are pointed by comments of jurors. Loudness and sharpness related metrics are prime metrics in sound quality index we composed. Effect of roller blind assay when it is attached to real vehicle was identified to evaluate the validity of index.

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A Study on the Spectrum Analysis for the Sound Synthesis of Piri (국악기 피리의 소리합성을 위한 음색분석 연구)

  • Kim, Hye-Jee;Yoon, Hye-Jung;Cho, Hyung-Je;Kim, Jun
    • Journal of Korea Multimedia Society
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    • v.9 no.7
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    • pp.801-807
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    • 2006
  • This study analyzed the timbral characteristics of Pliri by basis step for the sound synthesis for Piri, Korean traditional musical Instrument. By analyzing this material, we can find out three characteristics about the study of the spectrum analysis for the sound synthesis of Piri. First, compared the timbral characteristics of Piri with Oboe through the spectrum analysis, Second, analyzed the timbral characteristics by the sound occurrence process through the time zone analysis of the attack part of the sound started. Finally, analyzed the special characteristics of the vibrato that is important role of musical instrument performance. As a result, the timbral characteristics of Piri is that the volume of the high harmonics was appeared to be high unlike the general classical instrument and the noise quantity rapidly decreased in the sound attack part but the volume value of harmonics increased. And also vibrato that is performance technique is changed pitch and amplitude at the same time by contrast with the general classical instrument. Thus, the timbral characteristic of Piri by the harmonics and the timbre change by the attack part which is sound occurrence process and the change of the pitch and amplitude in the vibrato is characteristic that represented unique quality of Piri. We expect that this achievement can be applied to sound synthesis.

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