한국소음진동공학회논문집제 권제 호, pp. ~,. DOI :./KSNVE... 방음보호구종류별소음저감효과에대한주관적반응 Subjective Responses to the Anti-noise Effect According to Different Types of Soundproof-protector 김대군 * 김재수 Dae-Goon Kim and Jae-Soo Kim ( 년 월 일접수 ; 년 월 일심사완료 ) Key Words : Loud Noise( 고소음 ), Soundproof Protector( 방음보호구 ), Earplugs( 귀마개 ), Psycho-acoustics Experiment ( 청감실험 ) ABSTRACT Since the working machine generates an excessive loud noise as as its use-purpose and dimension, those damages are occurring to the exposed workers such as unpleasant sense, stress and occupational hearing-impaired. Accordingly, as one of the measures for prevention such loud noise, various soundproof protection tools were developed. However, such soundproof protection tools were presented the physical measured value only, it is real state that the psychological study result regard to the soundproof effect which the workers are actuy feeling, is not existing. On such point of view, the object on the typical and earcaps among the soundproof protection tools, this study has ever tried a subjective evaluation about the degree of soundproof effect through Psycho-acoustics experiment. It is considering that such study result could be utilized as the useful material when establishing the soundproof measure for the workers in the future. *. 서론 산업이발달함에따라작업장내다양한작업기계들이사용되어업무의편의와생산의증대를제공하였다. 근래에는무인작업기계들이상당수도입되어그편리성이증대되었지만기계가하지못하는단순가공, 조림, 점검등여전히작업자들만이할수있는부분이존재하고있다. 이러한작업장내의작업자들은불쾌감과스트레스, 직업성난청등의심각한위험을안고작업기계를작동시키며작업기계의고소음에대한차음및방음대책없이지속적으로고소음에노출되어있어그피해가 교신저자 ; 정회원, 원광대학교건축공학과 E-mail : soundpro@wku.ac.kr Tel : ()-, Fax : ()- * 정회원, 원광대학교건축공학과 발생 (,) 되고있다. 그예로직업성사고에의한상해나업무상질병에대해요양과보상을하고있는산업재해보상법에따르면소음성난청에의한직업병자는매년 ~ % 에이르는것으로나타났다. 따라서고소음작업기계로인한피해를방지하기위한대책중하나로다양한방음보호구가개발되고있으나이러한방음보호구는물리적측정치만제시되었을뿐작업자들이실제로느끼는소음저감효과에대한주관적인반응에관한연구는이루어지지않고있는실정이다. 이러한관점에서본연구에서는작업자들의방음보호구에대한주관적반응을파악하기위해방음보호구중대표적인귀마개와귀덮개를대상으로 개의고소음작업기계의소음특성을파악해보았으며, 방음보호구의주관적반응을평가하기위한평가어휘를설문조사를통해추출하였다. 이렇게추출된평가어휘로청감실험을 한국소음진동공학회논문집 / 제 권제 호, 년 /
김대군 김재수 실시하여고소음작업기계의소음에대해방음보호구의착용형태별로어느정도소음저감효과가있는지주관적인반응을평가해보았다.. 고소음작업기계와방음보호구의특성 기기구성및측정모습은 Fig. 과같다. 이연구에서각기계소음의특성을분석하기위하여사용된주파수범위는 Hz khz까지의 / 옥타브밴드로 초간 회측정한평균값을이용하. 고소음작업기계의측정및특성 () 고소음작업기계의측정방법고소음작업기계로부터발생되는소음을측정 () 하기위하여작업기계를정상적으로가동한상태에서노동부고시제 --( 작업환경측정및정도관리규정, 전문개정.. ) 에제조측정방법에의거하여측정 () 하였으며, 측정시소음계의위치는지면으로부터. m의높이에삼각대로고정하여설치하였고, 작업장내에설치되어있는고소음작업기계로부터소음계를통해들어오는신호를 DAT(digital audio tape recorder) 로현장에서녹음 () 하였다. 녹음시 calibrator를사용하여주파수분석시표준이되는, Hz에서 db을먼저 DAT에녹음한후, 녹음된신호를실험실에서 B&K사의 pulse multi analyzer system을이용하여분석하였다. 고소음작업기계의제원은 Table 과같으며, 측정 (a) Measuring scene (b) Composition of Measuring Apparatus Fig. Measuring scene and composition of measuring apparatus Table Specification of measuring object loud noise working machine Number Working machine Dimension db(a) Number Working machine Dimension db(a) Sm-type drill. kw. Circular electric router. kw. Disk sander. kw. Gloss grinder. kw. Common lathe kw. Polishing duplex grinder. kw. Table middle -sized revolving saw Middle -sized revolving saw CNC lathe kw. Facet grinder. kw. / 한국소음진동공학회논문집 / 제 권제 호, 년. kw. Stone grinder kw.. kw. Table chain-saw. kw. Vertical cutting chain-saw Sm-sized revolving saw. kw.. kw. Jewelry grinder. kw. Gypsum mill. kw. Table SCSI saw. kw. Talc material kw. Table vertical band saw machine. kw. Automatic plane. kw. Gemstone shearing machine. kw. Machine electric plane. kw. Rock cutter. kw. Stone burner machine kw. Vertical milling. kw. Chainsaw wood. kw. Steel processing saw. kw. Stone cutter kw. Fine jewelry grinder. kw. Stone cross-cutter kw. Air dust collector. kw.
방음보호구종류별소음저감효과에대한주관적반응 였으며, 동시에전대역음압레벨도 db(a) 값으로측정 분석하였다. () 고소음작업기계의특성고소음작업기계의소음특성은사용목적및제원에따라큰영향 (,,) 을받는다. 개고소음작업기계의주파수별소음특성을 Hz khz까지의주파수별로나누어분석한결과는 Fig. 와같다. Fig. 를보면주로석재가공을위해쓰이는석재연마기, 석재버너기, 석재재단기등은 khz이하에서유사한패턴을보이고있으며 khz부터는음압레벨이서서히증가하고있음을알수있다. 또한 주로모형을자를때쓰이는철재가공톱이나테이블전기톱, 수직절단전기톱등은저주파수에서고주파수로갈수록서서히증가하고있는형태를나타내고있다.. 방음보호구의제원및특성이연구에사용된귀마개및귀덮개는가장많이사용되고있는 M사의, 모델로제원및착용모습은 Table 및 Fig. 과같다. Table 및 Fig. 의소음감소율은 M사실험실의표준상태에서측정된값으로실제작업장에비해과대평가되어있으므로현장에적용하기에앞서 Sm-type Drill Air Dust Collector Disk Sander Common Lathe Circular Electric Router Gloss Grinder Table Middle-sized Revolving Saw Middle-sized Revolving Saw Polishing Duplex Grinder Stone Grinder..k k.k k k..k k.k k k (a) Characteristics by frequencies(~) (d) Characteristics by frequencies(~) CNC Lathe Table Chain-saw Facet Grinder Jewelry Grinder Vertical Cutting Chain-saw Sm-sized Revolving Saw Table SCSI Saw Table Vertical Band Saw Machine Gypsum Mill Talc Material..k k.k k k..k k.k k k (b) Characteristics by frequencies(~) (e) Characteristics by frequencies(~) Gemstone Shearing Machine Rock Cutter Vertical Milling Steel Processing Saw Fine Jewelry Grinder Automatic Plane Machine Electric Plane Stone Burner Machine Chainsaw Wood Stone Cutter Stone Cross-Cutter..k k.k k k..k k.k k k (c) Characteristics by frequencies(~) (f) Characteristics by frequencies(~) Fig. Characteristics of loud noising working machine 한국소음진동공학회논문집 / 제 권제 호, 년 /
김대군 김재수 제공되는소음감소율을제공된차음치의약 % 만을고려하여현장에적용시킬것을권고 () 하고있다.. 청감실험방법 (a) Earplugs(M) (b) Earcaps(M). 청감평가를위한평가어휘선정이연구에서는작업기계소음에대해노출시피험자로하여금반응의정도를판단하기위해선행 Vocabulary : loud (c) Earplugs-wearing shape (d) Earcaps-wearing shape Fig. Shape of Soundproof Protector Table Specification of the object soundproof protector Dimension Classification Earplugs() Earcaps() Type Soft foam type Rotary cup type method Noise reduction rate(nrr) Insert into EAC When rotary cup pushes whole of ear db* db* Almost not Little A little bit Noisy Fairly Vocabulary : Almost not Little A little bit Noisy Fairly Vocabulary : nervous Almost not Little A little bit Noisy Fairly Vocabulary : unpleasant Almost not Little A little bit Noisy Fairly NRR(dB) Vocabulary : sharp Almost not Little A little bit Noisy Fairly 귀마개 () 귀덮개 () db(a) (a) Average of soundproof protector Fig. Psycho-acoustic sheet NRR(dB) (a) earcaps (b) Fig. Scene of psycho-acoustics experiment 귀마개 () 귀덮개 () db(a) (b) Standard deviation of soundproof protector Fig. Noise reduction rate of soundproof protector Fig. Presentation process of sound source / 한국소음진동공학회논문집 / 제 권제 호, 년
방음보호구종류별소음저감효과에대한주관적반응 연구결과 (,,) 의어휘로구성된응답지 (sheet) 를사용하였으며, 어휘척도에따른반응의정도는 단계 SD척도를이용하였다. 일반적으로평가척도에서는 점, 점척도가많이사용되지만 점척도또한많이사용되고있다 (). 이연구는보다세밀한주관적평가를실시하기위해그점의수를 점척도로사용하였다. 이연구에서사용한응답지는 Fig. 와같다.. 청감평가방법및실험고소음작업기계에대한방음보호구의주관적반응평가를위한청감실험은원광대학교건축환경실험실내청감실험실에서실시하였으며, 실험에사용된청감실험실은.m m m의크기에 Hz에서잔향시간 (RT) 이.초, 음성명료도 (D) 는. %, 음성전달지수 (RASTI) 는 % 로써무향실 (anechoic chamber) 과같은조건을갖춘실험실이다. 실험에참여한피험자는 ~세의정상청력을지닌남자 명 ( %) 과여자 명 ( %) 으로대부분의피험자가소음에대한기초적인지식이있는대학생및대학원생들을대상으로하였다. 또한정확한청감평가를위해방음보호구의착용요령을숙지시키고실험전평가시트를나누어주어충분한설명과함께반복적으로음원을들려준뒤실험에참가하도록하였으며 Fig. 은청감실험모습이다. 음원은작업기계가위치한작업장에서 DAT를이용해녹음하였으며, 음원의제시과정은무향실안에스피커를통하여일정한간격을두고음원을 번씩들려주면서평가를진행하였다. 청감실험은무향실에서동시에 명씩진행하였으며한음원을들을때마다귀마개, 귀덮개, 귀마개 + 귀덮개순서대로총 Evaluation Valu Evaluation Value Evaluation Value (b) Noisy (c) Nervous (d) Unpleasant Evaluation Value Evaluation Valu (a) Loud (e) Sharp Fig. Response by each items before - wearing after-wearing soundproof protector of machinery noise 한국소음진동공학회논문집 / 제 권제 호, 년 /
김대군 김재수 번에걸쳐방음보호구의방음효과를평가하도록하였다. 음원제시과정은 Fig. 과같다.. 방음보호구의주관적반응평가를위한청감실험. 방음보호구의착용형태별주관적반응평가작업기계소음에대한방음보호구의착용전후에따른각항목별응답결과는 Fig. 과같다. Fig. 의기계소음의방음보호구착용전 후각항목별응답결과를보면착용시보다귀덮개 < 귀마개 < 귀덮개 + 귀마개병행착용의순으로청감상의소음저감개선이있는것으로평가되었으며, 상대적으로소음레벨이낮은고소음작업기계에서고소음의작업기계로갈수록소음저감개선정도가뛰어나높은음압레벨을가진고소음작업기계일수록효과적인것으로나타났다.. 방음보호구의주관적반응평가치개선량방음보호구의착용에따른청감상의개선정도를방음보호구미착용을기준으로파악해보면 Fig. 와같다. Fig. 의방음보호구의각항목별평가치개선량을보면모든항목에서착용형태와소음레벨에따라 단계미만부터 단계미만까지개선되었음을알수있으며, 단계는방음보호구의착용전 후를비교하였을때개선된수치를말한다............................. (b) Noisy........ (c) Nervous..................... 고소음작업기계의소음레벨에따른소음저감개선량방음보호구의착용별평가치개선량을소음레벨에.................. (d) Unpleasant.......... Evaluation Value Improved Quant............................................. (a) Loud........... (e) Sharp Fig. Evaluation value improved quantity by each items of soundproof protector / 한국소음진동공학회논문집 / 제 권제 호, 년
방음보호구종류별소음저감효과에대한주관적반응 따라분류해보면 Table 과같다. Table 의소음레벨에따라분류된방음보호구의착용별평가치개선량을보면소음저감효과를인지하여어휘변화를느끼는 단계이상은귀덮개착용시. db(a), 귀마개착용시.. db(a), 귀덮개 + 귀마개병행착용시는.. db(a) 부터로나타났다. 특히귀덮개 + 귀마개병행착용시 단계이상은. db(a) 부터, 단계이상은. db(a) 부터로가장뛰어난소음저감효과를보이는것으로평가되었다. 이러한결과를바 탕으로소음저감효과를보이는 단계이상부터개선단계별고소음작업기계의소음레벨개선량을방음보호구착용형태에따라그분포정도를나타내보면 Fig. 과같다. Fig. 에서평가치개선량 단계이상부터개선단계별고소음작업기계의소음레벨개선량을방음보호구착용형태에따라그분포를보면 단계이상 단계미만의평가치개선량평균은귀덮개착용시., 귀마개착용시., 귀덮개 + 귀마개병행착용시.로나타났으며, 단계 단계부터는 Table Evaluation value improved quantity by each wearing of soundproof protectors classified according to noise level(db(a)) Rating vocabulary classification Less than first step More than first step less than second step More than second step less than third step More than third step less than fourth step More than fourth step less than fifth step. and less... - - Loud earcaps. and less... - - -....... and less.... - - Noisy earcaps.and less... - - -.......and less.... - - Nervous earcaps. and less... - - -....... and less..... - Unpleasant earcaps. and less... - - -....... and less.... - - Sharp earcaps. and less... - - -...... 한국소음진동공학회논문집 / 제 권제 호, 년 /
김대군 김재수 () () () earcaps (c) More than fourth step less than fifth Step (parel wearing ) Fig. Improved quantity distribution of loud noise working machine in accordance soundproof protector wearing forms by improvement stages from more than second step of evaluation 귀덮개 + 귀마개병행착용시만소음저감효과가있어그평가치개선량평균을보면 단계이상 단계미만은., 단계이상 단계미만은.로나타났다. () (a) More than second Step Less than third Step () (b) More than third step less than fourth step (parel wearing ). 결론고소음작업장에서방음보호구의착용에따른방음효과를알아보기위해실시한청감실험결과는다음과같다. () 고소음작업기계소음에대한방음보호구의착용형태별주관적반응평가결과는방음보호구미착용시보다귀덮개 < 귀마개 < 귀덮개 + 귀마개병행착용의순으로청감상의소음저감개선이있는것으로평가되었으며, 상대적으로소음레벨이낮은고소음작업기계에서고소음의작업기계로갈수록소음저감개선정도가뛰어나높은음압레벨을가진고소음작업기계일수록효과적인것으로나타났다. () 소음저감효과를인지하여어휘변화를느끼는평가치개선량 단계이상은귀덮개착용시. db(a), 귀마개착용시.. db(a), 귀덮개 + 귀마개병행착용시는.. db(a) 부터로나타났다. 특히귀덮개 + 귀마개병행착용시 단계이상은. db(a) 부터, 단계이상은. / 한국소음진동공학회논문집 / 제 권제 호, 년
방음보호구종류별소음저감효과에대한주관적반응 db(a) 부터로가장뛰어난소음저감효과를보이는것으로평가되었다. () 소음저감효과를보이는평가치개선량 단계이상부터개선단계별로고소음작업기계의개선량을방음보호구착용형태에따른그분포정도는 단계이상 단계미만의평가치개선량평균은귀덮개착용시., 귀마개착용시., 귀덮개 + 귀마개병행착용시.로나타났으며, 단계 단계부터는귀덮개 + 귀마개병행착용시만소음저감효과가있어그평가치개선량평균을보면 단계이상 단계미만은., 단계이상 단계미만은.로나타났다. 위와같은연구결과는작업기계의고소음으로인한작업자들의방음대책시유용한자료로활용될수있을것으로사료되며향후추가적인작업기계소음의특성을파악해평가해본다면보다더정확한자료가될것으로사료된다. 참고문헌 () Kim, J. S.,, Noise and Vibration Study (Revision nd Edition), Sejin Publishing Co. () Kim, J. S., Yang, M. W.,, Architectural Acoustic Design Methodology, Seowoo Publishing Co. () M Technical Data,. () Yoo, H. J., Han, K. Y., Seo, J. S., Park, J. H., Kim, J. S.,, Vocabulary Research for Evaluation on Equipment Noise of Machine Room, The Society of Air-conditioning and Refrigerating Engineers of Korea, Summer General Meeting for Academic Study. () Song, M. J., Lee, J. Y., Kim, S. W.,, A Study on the Proper Vocabularies for Evaluating Floor Impact Sound in Apartment Houses Considering Rating Methods. () Joo, D. H., Kook, J. H., Kim, J. S.,, Typicalization of Vocabulary for Evaluation on Machinery Noise generates at Loud- Workplace, The Korean Society for Noise and Vibration Engineering, General Meeting for Academic Study. () Yoon, J. H., Choi, D., Kim, J. S.,, A Study on Noise Characteristic Generates when Jewelry Processing, The Korean Society for Noise and Vibration Engineering, General Meeting for Academic Study. () Yoon, J. H., Kim, D. G., Kim, J. S.,, A Study on Property of Machinery Noise Generates at Model Workshop, Korean Society of Environmental Engineers, General Meeting for Academic Study. () Lyon, R. H., Cann, R. G., Bowen, D. L.,, Measurement and Analysis of Machinery Noise, Ch. of Handbook of Acoustical Measurements and Noise Control () Leather, P., Beale, D., Sullivan, L.,, Noise, Psychosocial Stress and Their Interaction in the Workplace, Journal of Environmental Psychology () Fernández., M. D., Quintana, S., Chavarría, N. J. A.,, Noise Exposure of Workers of the Construction Sector, Applied Acoustics. () Tak., S. W., Davis, R. R., Calvert, G. M.,, Exposure to Hazardous Workplace Noise and Use of Hearing Protection Devices Among US Workers, American Journal of Industrial Medicine. 한국소음진동공학회논문집 / 제 권제 호, 년 /