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Full-Text Articles in Acoustics, Dynamics, and Controls
On The Area-Averaged Effective Sound Absorption Coefficient Of Porous Materials Excited By A Monopole, Franck Sgard, Noureddine Atalla, Olivier Robin, Alain Berry
On The Area-Averaged Effective Sound Absorption Coefficient Of Porous Materials Excited By A Monopole, Franck Sgard, Noureddine Atalla, Olivier Robin, Alain Berry
Études primaires
The area-averaged effective sound absorption coefficient (SAC) of a rigid-backed homogeneous porous material subjected to a monopole excitation is calculated as the absorbed-to-incident sound power ratio. Using Allard's model to describe the sound propagation above the porous material, an analytical model for this power-based SAC is proposed and proves to give a good approximation of the sound absorption performance under monopole excitation of sufficiently large areas of material. The impact of factors on the power-based SAC, such as monopole height, material radial dimension used to calculate the sound powers, and material properties is discussed. The power-based SAC frequency-dependent behavior is …
Développement D’Un Système De Mesure Pour La Caractérisation Des Traitements Absorbants En Laboratoire, Alain Berry, Olivier Robin, Thomas Dupont, Franck Sgard
Développement D’Un Système De Mesure Pour La Caractérisation Des Traitements Absorbants En Laboratoire, Alain Berry, Olivier Robin, Thomas Dupont, Franck Sgard
Rapports de recherche scientifique
Le bruit constitue une préoccupation de plus en plus importante et généralisée dans le monde. Selon l’Organisation mondiale de la Santé, environ une personne sur quatre dans le monde souffrira de déficience auditive à des degrés divers d’ici à 2050. Dans de nombreux pays et régions du globe, le bruit représente le second facteur environnemental provoquant le plus de dommages sanitaires, et ce derrière la pollution atmosphérique. Sur un volet cognitif ou perceptif, le bruit environnemental peut par exemple perturber le sommeil et gêner l’apprentissage en milieu scolaire. Dans un milieu de travail, il peut perturber la bonne compréhension/perception de …
Étude De L’Applicabilité De Haut-Parleurs Paramétriques Au Développement De Nouveaux Concepts D’Alarmes De Recul, Olivier Robin, Alain Berry, Hugues Nélisse
Étude De L’Applicabilité De Haut-Parleurs Paramétriques Au Développement De Nouveaux Concepts D’Alarmes De Recul, Olivier Robin, Alain Berry, Hugues Nélisse
Rapports de recherche scientifique
L’utilisation d’alarmes de recul est obligatoire sur une majorité de véhicules lourds et reste un moyen largement utilisé pour prévenir et alerter les personnes œuvrant à proximité de ces véhicules. Des études antérieures, réalisées par l’IRSST, ont montré les limites d’efficacité des alarmes utilisées en milieu de travail pour minimiser le risque à la sécurité des travailleurs. De plus, les alarmes de recul, par le son de niveau élevé et très typé qu’elles produisent, sont régulièrement une source de nuisance importante pour les travailleurs, et aussi pour les riverains. Ces problèmes de gêne et de perception sonore pour les travailleurs …
Principle Of An Acoustical Method For Estimating The Centroid Position Of The Earcanal Wall Normal Velocity Induced By Bone-Conducted Stimulation: Numerical Evaluation, Kevin Carillo, Olivier Doutres, Franck Sgard
Principle Of An Acoustical Method For Estimating The Centroid Position Of The Earcanal Wall Normal Velocity Induced By Bone-Conducted Stimulation: Numerical Evaluation, Kevin Carillo, Olivier Doutres, Franck Sgard
Études primaires
The occlusion effect is commonly experienced as the altered perception of one’s own physiological noise when the earcanal entrance is blocked. Objectively, this phenomenon corresponds to an acoustic pressure increase in the occluded earcanal. The occlusion effect originates from the earcanal wall normal vibration and depends on the spatial distribution of the latter. At low frequencies, this spatial distribution can be characterized by the position of its centroid along the earcanal middle axis. This paper describes the principle of an acoustical method for estimating this centroid position at low frequencies. The proposed method consists in measuring the eardrum acoustic pressure …
Numerical Investigation Of The Earplug Contribution To The Low-Frequency Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard
Numerical Investigation Of The Earplug Contribution To The Low-Frequency Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard
Études primaires
The use of earplugs is commonly associated with an increased perception of the bone-conducted part of one's own physiological noise. This phenomenon is referred to as occlusion effect and is most prominent at low frequencies. Several factors influence the occlusion effect, such as the ear anatomy; the bone-conducted stimulation; and the type of occlusion device and its fit, insertion depth, and material properties. The latter factor is of great interest to potentially reduce the occlusion effect of passive earplugs. This paper investigates the mechanism(s) of contribution of earplugs to the objective occlusion effect. A two-dimensional axi-symmetric finite element model of …
On The Removal Of The Open Earcanal High-Pass Filter Effect Due To Its Occlusion: A Bone-Conduction Occlusion Effect Theory, Kevin Carillo, Olivier Doutres, Franck Sgard
On The Removal Of The Open Earcanal High-Pass Filter Effect Due To Its Occlusion: A Bone-Conduction Occlusion Effect Theory, Kevin Carillo, Olivier Doutres, Franck Sgard
Études primaires
The occlusion effect is commonly experienced by in-ear device wearers as an increased loudness sensation of bone-conducted low frequency sounds. A widespread theory proposed by Tonndorf and based on a simplified electro-acoustic model describes the phenomenon as the removal of the open earcanal high-pass filter effect due to a perfect or partial occlusion. However, this filter has not been clearly defined and several ambiguities remain. Revisiting the model, a second order high-pass filter effect for the volume velocity transferred between the earcanal wall and the eardrum is highlighted. This filter remains for partial occlusion but vanishes for perfect occlusion. In …
Simulation Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation Using A Three-Dimensional Finite-Element Model Of A Human Head, Huiyang Xu, Franck Sgard, Kévin Carillo, Éric Wagnac, Jacques De Guise
Simulation Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation Using A Three-Dimensional Finite-Element Model Of A Human Head, Huiyang Xu, Franck Sgard, Kévin Carillo, Éric Wagnac, Jacques De Guise
Études primaires
The occlusion effect (OE) refers to the phenomenon that more bone-conducted physiological sounds are transmitted into the earcanal when it is blocked and may cause discomfort on users of hearing protection devices. Models have been proposed to study the OE as they can help understand the physical mechanisms and can be used to evaluate the individual contribution on the OE of the factors that may affect it (i.e., occlusion device, ear anatomy, and stimulation). The existing finite element models developed to study the OE are limited by their truncated ear geometries. In order to progress in the understanding of the …
Theoretical Investigation Of The Low Frequency Fundamental Mechanism Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard
Theoretical Investigation Of The Low Frequency Fundamental Mechanism Of The Objective Occlusion Effect Induced By Bone-Conducted Stimulation, Kevin Carillo, Olivier Doutres, Franck Sgard
Études primaires
The objective occlusion effect induced by bone-conducted stimulation refers to the low frequency acoustic pressure increase that results from occluding the ear canal opening. This phenomenon is commonly interpreted as follows: the bone-conducted sound “leaks” through the earcanal opening and is “trapped” by the occlusion device. This instinctive interpretation misrepresents the fundamental mechanism of the occlusion effect related to the earcanal impedance increase and already highlighted by existing electro-acoustic models. However, these models simplify the earcanal wall vibration (i.e., the origin of the phenomenon) to a volume velocity source which, in the authors' opinion, (i) hinders an exhaustive comprehension of …