Theoretical investigation of the low frequency fundamental mechanism of the objective occlusion effect induced by bone-conducted stimulation

Type de document

Études primaires

Année de publication

2020

Langue

Anglais

Titre de la revue

Journal of the Acoustical Society of America

Première page

3476

Dernière page

3489

Résumé

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 the vibro-acoustic behavior of the system, (ii) hides the influence of the earcanal wall vibration distribution, and (iii) could blur the interpretation of the occlusion effect. This paper analyzes, illustrates, and interprets the vibro-acoustic behavior of the open and occluded earcanal using an improved finite element model of an outer ear in conjunction with an associated electro-acoustic model developed in this work. The two models are very complementary to dissect physical phenomena and to highlight the influence of the earcanal wall vibration distribution, characterized here by its curvilinear centroid position, on the occlusion effect.

Mots-clés

Protection de l'ouïe, Hearing protection, Évaluation du confort, Comfort assessment, Propagation du son, Sound propagation

Numéro de projet IRSST

n/a

Ce document n'est pas disponible pour le moment.

Partager

COinS