• Journal of the Ergonomics Society of Korea
• /
• v.1 no.2
• /
• pp.33-37
• /
• 1982

인간의 가청 영역은 어린이의 경우에 20 Hz-20KHz로 알려져 있다. 그러나, 20Hz 이하의 초저주파 영역에서도 그 음압 레벨이 높은 경우에는 인간이 감지할 수 있다는 사실이 알려졌는데, 그것은 듣느다기 보다는 느낀다는 것으로 표현되고 있다. 초저주파 음이 인간에게 미친다고 생각되는 좋지않은 영향 때문에, 60년대말 이후에 새로운 종류의 연구 과제로서, 음향학자, 심리학자, 의학자 등에 의해 활발히 연구되고 있다. 게다가 경제의 고도성장 및 환경 개선의 노력에 따라, 대기 오염, 가청 소음, 진동 등의 전형적인 환경 공해 외의 초저주파음 공해에 대한 사람들의 인식과 불평이 문제시 되고 있다. 즉, 고주파수의 음이 잘 소음된 곳에서, 소리가 잘 들리지는 않으나 항상 사람들을 불안하게 하는 그 무엇이 있다는 것이다. 이에따라 지난 몇 년간 인간의 산업 활동과 관계 있는 높은 레벨의 초조주파 소음의 발생원이 확인되었고, 그에 따른 대책 및 설계 단계에서의 고려가 요구되고 있다.

• The Journal of the Acoustical Society of Korea
• /
• v.40 no.1
• /
• pp.73-83
• /
• 2021

Wind power energy harvesting has a big potential as a future clean energy resource, but accompanies infrasonic noises. The infrasound is difficult to shield and can induce various negative physiological effects. In this study, the Wind Turbine Syndrome (WTS) caused by the infrasonic noises are introduced, and the technical aspects for the measurement and management of the infrasonic noises from wind power plants are discussed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.616-620
• /
• 2002

가청범위의 주파수보다 낮은 소리, 즉 초저주파음과, 가청음 중 주파수가 낮은 음을 합하여 저주파음으로 분류하기도 하는데, 대략 100Hz 이하의 주파수를 갖는 음을 가리킨다. 인간이 느끼는 저주파음에 대한 영향은 여러 범위로 조사되고 있으며 주로 청력손실과 불쾌함에 미치는 영향에 초점을 맞추고 있다.(중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.1482-1489
• /
• 2007

In this paper, characteristics of infrasound and low-frequency noise emission from large modern wind turbines are experimentally investigated. The sound measurement procedures of IEC 61400-11 and ISO 7196 are utilized to field test and evaluation of noise emission from each of 1.5 MW and 660 kW wind turbines using the stall regulation and the pitch control for the power regulation, respectively. It was found that the G-weighted SPLs of low-frequency noise including infrasound shows positive correlation with the wind speeds, irrespective of methods of power regulation. This highlights the potential complaint of local community against the infrasound and low-frequency noise of wind turbines. The comparison of measured data with the existing hearing thresholds and criteria curves shows that it is highly probable that the low-frequency noise from the 1.5 MW and 660 kW wind turbines in the frequency range over 30 Hz leads to the psychological complaint of ordinary adults, and that the infrasound in the frequency range from 5 Hz to 8 Hz causes the complaint by rattling the house fitting such as doors and windows.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.05a
• /
• pp.887-890
• /
• 2007

The low frequency noise, including infra-sound is known to affect human physiology and psychology. Guidelines and measurement method of low frequency noise has been introduced in several countries in order to evaluate low frequency noise. In this work, low frequency characteristics of Daejeon subway was investigated in terms of the noise level and spectrum in the interior of running subway car and the subway station. The interior sound pressure level of the passenger car was between 60 and 102 dB in the frequency range of $1{\sim}250$ Hz.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.11
• /
• pp.1193-1197
• /
• 2005

The low frequency noise below 200 Hz, including inaudible infra-sound, is known to affect human physiology ; circulation, respiration, nerve, endocrine, etc. Legislation has been introduced in several countries regarding evaluation guideline and measurement method of low frequency noise. In this work, low frequency characteristics of the Seoul subway transportation system was investigated in terms of the noise level and spectrum in the interior of running passenger car and the subway station. The interior sound pressure level of the passenger car was between 60 and 105 dB in the frequency range of $1{\sim}200\;Hz$ and varied with car speed. The marked sound pressure level peak at 8 Hz, infra-sound, observed for the most of Lines is shown to correspond to the resonance frequency of passenger car. The level of station platform noise was lower than the interior noise of running car because of the lower speed at arriving/departure. The results indicated that the interior noise level of running passenger car was inside the oppressive feeling region, proposed by Ochiai, in the frequency range of $20{\sim}80\;Hz$ which makes a little concern.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.49 no.3
• /
• pp.175-183
• /
• 2021

This paper studies measurement of sonic boom created by supersonic flight and its arrival angle estimation techniques. Since sonic boom propagates as an impulsive noise and includes infrasound frequency, we propose measurement instrumentation acquiring sonic boom signature without distortion. And we suggest the methodology for an arrival angle estimation with its performance analysis in accordance with sensor array configurations. The performance of our estimator is verified by comparing theoretical performance bound with statistics of its Monte-Carlo simulation results. Furthermore, we presents the analysis of the sonic boom measurement from real flight tests. This work provides an intuitive concept for sensor array configurations and measurement instrumentation.