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dc.contributor.authorSides, Jonathan Drapalaen_US
dc.date.accessioned2011-08-06T16:05:50Z
dc.date.available2011-08-06T16:05:50Z
dc.date.issued2004-08-06en_US
dc.identifier.otheretd-08202004-100252en_US
dc.identifier.urihttp://hdl.handle.net/10919/10072
dc.description.abstractCircumaural ear cups have been used for decades as an effective way of protecting users from high noise fields. Over the decades, a number of researchers dedicated their time to understanding the dynamics that govern the attenuation of hearing protectors. This thesis duplicates some of this work with newer technology and better data processing ability. In addition to revitalizing the accepted knowledge of hearing protector technology, this thesis is the first documented effort to show how the previously ignored air leak, known to exist between the ear cup and the head, has a profound effect on the low and mid frequency attenuation of a circumaural hearing defender. Past research focused on the mechanical vibration of the cup on the seal as the main source of noise within the ear cup. This mechanical vibration, known as the piston resonance exists, and affected noise attenuation within the ear cup. A reasonably sized air leak of 160 e-7 m2 however, overwhelmed the piston resonance. An air leak of this size was shown to degrade noise attenuation by over 50 dB at 40Hz and 30 dB at 200 Hz when compared to a no-leak case. Further testing also suggested that the air leak has the ability to continue adding energy into the cup up to 3000 Hz.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartMasterPDF3.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectAttenuationen_US
dc.subjectDefenderen_US
dc.subjectFrequencyen_US
dc.subjectNoiseen_US
dc.subjectPassiveen_US
dc.subjectEaren_US
dc.titleLow Frequency Modeling and Experimental Validation of Passive Noise Attenuation in Ear Defendersen_US
dc.typeThesisen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreeMSen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairSaunders, William R.en_US
dc.contributor.committeememberBurdisso, Ricardo A.en_US
dc.contributor.committeememberWest, Robert L. Jr.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08202004-100252en_US
dc.date.sdate2004-08-20en_US
dc.date.rdate2004-08-20
dc.date.adate2004-08-20en_US


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