Context : The selection of a hearing protector, the last bastion to protect against exposure to noise, is mainly based on the acoustic attenuation it can provide. While knowledge on the attenuation of hearing protectors for continuous noise has progressed in recent years, that on attenuation for industrial impulse noise is less advanced both in terms of metrology and in terms of modeling. A model relaxing the limits of existing models and allowing or a better understanding of the transmission of waves in the ear/protector system with a view in particular to improving the design of protectors and the methods for measuring their performance against impulse noise is lacking. Recent progress made on the numerical modeling of hearing protection for continuous noises and the increasing use in other applications of the Bayesian formalism integrating all the uncertainties of the problem, make it possible to consider the development of such a model. It is in this perspective of designing a probabilistic model by finite elements (FE) of the acoustic response of the auditory canals of a human head, equipped or not with a protector, excited by impulse industrial noises and including all the transmission paths through tissues, that a research program is proposed. This research program is divided into four specific objectives: OS1) Model the acoustic response of the unprotected ear; OS2) Model the acoustic response of hearing protectors; OS3) Model the acoustic response of the ear coupled to a protector; OS4) Exploit FE models to understand the mechanisms of sound transmission in the earcanal open or occluded by a protector, taking into account uncertainties.
Subject of the Ph.D. project: This topic tackles the specific objectives OS1 and OS4 and consists in developing a probabilistic model by FE of the acoustic response of the open earcanal for excitation by industrial impulse noise taking into account the transmission paths through the head. The model will be calibrated/validated in a Bayesian framework against measurements on the human subject from which the head model is reconstructed and will be used to study the mechanisms of sound transmission in the open earcanal.
Main tasks : In addition to carrying out his·her doctoral project in compliance with the rules of research ethics, the student will contribute to the writing of deliverables (e.g., articles, presentations, reports) and will be encouraged to present his·her work at international scientific conferences.
Contact: Send resume + cover letter to Franck Sgard (Franck.Sgard@irsst.qc.ca)