차량 내 음향 장치의 음압수준 변화에 따른 사용자의 주관적인 지각 차이에 대한 연구

권상현(Sanghyun Kwon),반상우(Sangwoo Bahn),김제용(Jeyong Kim),강신규(Shinkyu Kang),윤명환(Myung Hwan Yun) 대한인간공학회 2010 대한인간공학회 학술대회논문집 Vol.2010 No.10

When people hear sounds through sound system, perceptive loudness of each sound pressure level varies with each level. This difference causes some confusion in adjusting volume level and designing the volume level of sound systems. According to previous studies, it is known that perceptive sensitivity of variation in sound pressure level depends on the sound pressure level and frequency of sound source. However, quantitative analysis on user’s perceptive sensitivity of sound level which they actually perceive from the change of sound pressure level has not been studied yet. This study aims to understand the perceptive sensitivity of variation in sound pressure level for some specific frequency bands. To this end, 118 sound samples (frequencies: 500 ㎐, 1 ㎑, 2 ㎑, sound pressure levels: from 40㏈ SPL to 100㏈ SPL) were evaluated by 27 participants (male: 17, female: 10) in the condition of driving automobile. Based on the results of subjective ratings of unit change of sound pressure level and 2㏈ SPL, the characteristics of perceptive sensitivity of variation in sound pressure level were identified. Also, through curve fitting analysis of the subjective rating results, perceptive sensitivity curves of each frequency were estimated. According to the results, when frequency is high, the perceptive sensitivity tends to be more sensitive than the case of low frequency and the sensitivity curve was estimated to have cubic relation. These results could be used to adjust the volume level of sound system in automobile to meet customer’s perceptive characteristics and needs.

경보음 종류에 따른 유발행동 유형에 관한 연구

오소영,함승희,이준 한국도로학회 2024 한국도로학회논문집 Vol.26 No.2

PURPOSES : This study focuses on how quickly emergency alarm facilities recognize a fire, respond to evacuation behavior, and induce appropriate behavior in response to the fire alarm sound by listening to the fire alarm sound from a sound device. METHODS : Prior research on alarm sounds affecting evacuation behavior was identified, and a subjective evaluation of alarm sounds was conducted to study the most appropriate evacuation-inducing behavior for alarm sounds. In the event of a fire, a subjective evaluation of the sound pressure level and frequency analysis of the sound system, which affects the occupants in the building, were conducted to analyze the type of alarm sound and evacuation behavior. RESULTS : As a result of the subjective evaluation of the occupants’ listening risk, there was little cognitive response to the change in sound pressure level according to frequency. It was found that the alarm sound could give a sense of crisis or tension owing to the difference in sound pressure level change according to the change in time difference. CONCLUSIONS : In conclusion, with high sound pressure and large decibel deviation, the evacuation behavior of respondents after education was more active in the wake-up call that made a sound that seemed to be torn.

Transmission loss of a silencer using resonator arrays at high sound pressure level

Sang-Hyeon Seo,김양한,김광준 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2

Helmholtz resonator is generally used to reduce the low frequency noise. However, it has only high transmission loss in a narrow band at the resonance frequency. In order to obtain broad band transmission loss, studies of a silencer using various resonator arrays have been carried out. These previous studies have been limited to low incident sound pressure level conditions with no change of impedance with respect to pressure. In the case of high sound pressure, the resistance increases due to nonlinear behavior at the neck of a resonator. As a result, the desired noise reduction performance cannot be achieved due to the transmission loss decrease. To predict the transmission loss of a silencer using resonator arrays at high sound pressure level, impedance variation depending on the incident sound pressure level should be considered. Furthermore, resonator’s numbers and order of arrangement are significant design parameters for design of transmission loss shape.

중공관 형태별 흡음 효과에 관한 실험적 연구

손철수 啓明大學校 産業技術硏究所 1999 産業技術硏究所 論文報告集 Vol.22 No.2

The purpose of this research is to investigate the performance characteristics of sound absorption at the form of voided circular tube. To do this research, the method for field measurement of floor impact sound level was used following the Korea Standard F2810-1996. Two kinds of voided circular form are used for this research. The results are as follows; 1. The main factor to effect the performance characteristics of sound absorption is sound-absorbing materials at the voided circular tube. 2. The main factor to effect the difference of Sound Pressure Level is the form of circular tube in the concrete slab. 3. The form of circular tubes effects the performance characteristics of sound absorption at the circular tube. More study will be needed about the depth and distance of sound absorption materials, and the characteristics of sound absorption materials.

도로 기하구조에 따른 차량 Microphone 위치별 소음 영향 분석

문학룡,한대철,강원평 한국도로학회 2013 한국도로학회논문집 Vol.15 No.4

PURPOSES: The purpose of study is to understand the characteristic of driving noise from the front and rear tire for effective active noise cancellation application. METHODS : As literature review, noise measurement methods were reviewed. Noise measurement conducted at three kind of section by road slope using CPX(Close Proximity Method). Noise data was compared by total sound pressure level and 1/3 octave band frequency sound pressure level. Also, each section was compared by T-test using SPSS. RESULTS : In the case of the uphill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low and high frequency band. In the case of high slope section of Sangsaek-Ri, the sound pressure level of the front tire was higher than that of the rear tire in high frequency. Also, in the case of the downhill section, it was shown that the sound pressure level of the front tire at Sugwang-Ri and Sinchon-RI sections was higher than that of the rear tire in low frequency band. However, the sound pressure levels of both the front and rear tires were approximately the same in the high slope section of Sangsaek-Ri. The result of T-test showed that total sound pressures of the front and rear tires were not different from each other in the case of high slope and high speed. CONCLUSIONS: Road slope was not an important variable for effective active noise cancellation.

방음벽에 미치는 바람의 영향에 관한 연구

여운호(Woon-Ho Yeo) 한국환경관리학회 2007 環境管理學會誌 Vol.13 No.4

방음벽에 미치는 바람의 영향을 연구하기 위해 인천국제공항고속도로 및 그 밖의 3개 고속도로에 대하여 조사하였다. 그리고 교통 소음도를 상동 풍림아파트 및 검암동 풍림아파트에서 측정하였다. 방음벽의 높이는 대부분 5m와 10m 사이였다. 상동 풍림아파트 1층과 최상층에서 측정한 교통소음도는 61.0㏈(A) 및 74.6㏈(A)였다. 검암 풍림아파트 1층과 최상층에서 측정한 교통소음도는 64.2㏈(A) 및 69.2㏈(A)였다. 최상층에서 측정한 소음도가 1층에서 측정한 소음도 보다 더 높았는데 그 이유는 방음벽의 높이가 충분히 높지 않기 때문이다. 그리고 최상층에서 측정한 소음도는 환경소음기준값을 초과하였다. 만일 방음벽 높이가 더 높아지면 방음벽은 바람의 영향을 받을 것으로 보이며, 풍압에 의해 붕괴 가능성도 있을 수 있다. In order to study on the effect of wind to sound barrier the Incheon International Airport Expressway and 3 expressways were researched. And traffic noise levels were measured at Sangdong Punglim APT and Geumam Punglim APT. The heights of sound barriers are between 5m and 10m. The traffic noise levels measured at the 1st floor and the highest floor of Sangdong Punglim APT were 61.0㏈(A) and 74.6㏈(A). And the traffic noise levels measured at the 1st floor and the highest floor of Geumam Punglim APT were 64.2㏈(A) and 69.2㏈(A). The noise levels measured at the highest floor were higher than those measured at the 1st floor because the height of sound barrier is low. And the noise levels measured at the highest floor were higher than Standard Environmental Noise Level. If the height of sound barrier is higher sound barrier is pressured by wind. And sound barrier can be broken by wind pressure.

Assessment of traffic-induced low frequency sound radiated from a viaduct by field experiment

Kawatani, M.,Kim, C.W.,Nishitani, K. Techno-Press 2010 Interaction and multiscale mechanics Vol.3 No.4

This study is intended to assess low frequency sound radiated from a viaduct under normal traffic. The bridge comprises steel box girders and wide cantilever decks on which vehicles pass. The low frequency sound and the acceleration response of the bridge under normal traffic are measured to investigate how bridge vibrations affect the low frequency sound observed near the bridge. Observations demonstrate that strong relationships exist between frequency characteristic of bridge's acceleration response and the sound pressure level of low frequency sound. A noteworthy point is that the dynamic feature of the sound pressure level is mostly affected by dynamic feature of the span locating near the observation point.

한국어음청각검사를 위한 기준음압레벨에 대한 고찰

한희경,조수진,이경원,이정학 한국청각언어재활학회 2009 Audiology and Speech Research Vol.5 No.1

According to the international regulations for the standards, the reference sound pressure level (RSPL) for speech audiometry (SA) is based on the reference speech recognition threshold level (RSRTL). The RSRTL for Korean speech audiometry is not established yet. Thus, the purpose of this study was to obtain basic data for calculating the RSRTL using Korean speech sounds. Subjects consisted of 42 adults with normal hearing sensitivity. Puretone thresholds (PTs) were obtained in 2 dB steps at each octave band. Korean 70 bisyllabic words were used to measure speech recognition thresholds (SRTs). The SRT was defined as the level at 50% of correct responses based on the logistic regression analysis for the results of the psychometric function test. The test was performed from -6 dB HL up to the level at or above 95% of correct responses in 2 dB steps. Results showed that the mean SRT was 26.59 dB SPL with the standard deviation of 4.25 dB, which was 6.59 dB greater than the RSRTL of English speech sounds. These results suggest that the RSRTL be recalculated for Korean speech audiometry for each type of headphone.

기술사례 : 발파에 의한 수중음압레벨 예측 사례연구

박정일 ( Jeong Il Park ),강추원 ( Choo Won Kang ),노영배 ( Young Bae Noh ),고진석 ( Chin Surk Ko ) 대한화약발파공학회 2011 화약발파 Vol.29 No.2

발파공법 위주의 공사를 진행하다 보면 민원발생의 대부분을 차지하고 있는 발파공해는 소음과 진동이다. 이로 인해 발파설계시 안정성을 가장 우선적으로 고려하며, 그중에서도 수중소음을 제어하기 위한 노력이 필요하다. 본 연구에서는 발파로 인한 공사 작업이 진행될 때 거리와 지발당장약량을 적용하여 수중음압을 예측하고 그 수중음압을 이용하여 얻은 수중음압레벨 예측값의 타당성을 검토해 보기 위해 실제 측정한 지역과 다른 지역에서 검증을 하여 실제 측정값과 예측값을 비교해 보았다. Most of the blast pollution that causes complaints is noise and vibration. Hence, special attentions need to be paid to controlling the underwater noise in designing blasting for those areas. This study estimated underwater sound pressure using distance from blasting and charge per delay and underwater sound pressure level using the underwater sound pressure. To identify the validity of the estimated value, the study demonstrated the results at other areas and compared actual results with estimated results.

슬림형 룸에어컨 설계 인자에 관한 연구

신종진,이희술,김종문,민준기,오상경 대한설비공학회 2005 설비공학 논문집 Vol.17 No.2

Numerical simulations and experiments were conducted to analyze the design parameters for a slim room air-conditioner. These design parameters included a fan shape, a front panel, a scroll shape, a bell mouth, a distance between a fan and a heat exchanger, etc. Each design parameter was analyzed numerically and / or experimentally in terms of the flow rate and the sound pressure level, which should be the most influential factors for developing the slim room air-conditioner. The fan with a uniform height showed a better performance than that with a linearly varying height. It is recommended to use a front grill rather than a front panel according to sound pressure levels since the front panel itself is a huge resistance to the inlet flow. A redesigned scroll shape by changing the rotational direction of a fan also contributed a lot to lowering the sound pressure level. There existed a distance between a fan and a heat exchanger, where flow rates increased effectively.