title: A finite element model to predict the sound attenuation of earplugs in an acoustical test fixture.
abstract: Acoustical test fixtures (ATFs) are currently used to measure the attenuation of the earplugs. Several authors pointed out that the presence of an artificial skin layer inside the cylindrical ear canal of the ATFs strongly influenced the attenuation measurements. In this paper, this role is investigated via a 2D axisymmetric finite element model of a silicon earplug coupled to an artificial skin. The model is solved using COMSOL Multiphysics (COMSOL(®), Sweden) and validated experimentally. The model is exploited thereafter to better understand the role of each part of the earplug/ear canal system and how the energy circulates within the domains. This is investigated by calculating power balances and by representing the mechanical and acoustical fluxes in the system. The important dissipative role of the artificial skin is underlined and its contribution as a sound transmission pathway is quantified. In addition, the influence of both the earplug and the artificial skin parameters is assessed via sensitivities analyses performed on the model.
authors.affiliation: Department of Mechanical Engineering, École de Technologie Supérieure, 1100 rue Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canada.
authors.forename: Guilhem
authors.initials: G
authors.lastname: Viallet
authors.affiliation: IRSST, Direction Scientifique, 505 Boulevard de Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada.
authors.forename: Franck
authors.initials: F
authors.lastname: Sgard
authors.affiliation: Department of Mechanical Engineering, École de Technologie Supérieure, 1100 rue Notre-Dame Ouest, Montréal, Québec, H3C 1K3, Canada.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Laville
authors.affiliation: IRSST, Service de la Recherche, 505 Boulevard de Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Boutin
mesh_terms: D000162:Acoustics; D003198:Computer Simulation; D004424:Ear Canal / Q000033:anatomy & histology*; D004430:Ear Protective Devices; D004867:Equipment Design; D020342:Finite Element Analysis; D006801:Humans; D008953:Models, Anatomic; D008962:Models, Theoretical; D009622:Noise / Q000517:prevention & control*; D009716:Numerical Analysis, Computer-Assisted; D015203:Reproducibility of Results; D012828:Silicones; D017768:Skin, Artificial
chemical_list: D012828:Silicones