This thesis presents work on the analysis of the dynamic behavior of the human ear canal. The work is based on two studies designed during the project, a pilot study with 30 normal hearing subjects and a main study with 42 hearing impaired subjects, all hearing-aid users. The main focus is on the extraction and analysis of the shape and deformation of the ear canal due to movements of the mandible, leaning over, and turning of the head. Methods for surface registration with focus on non-rigid registration are presented, as well as a wide range of statistical methods used for analyzing the shapes and deformation fields. The results show that the ear canal changes shape significantly in all subjects and that the deformation is more complicated than previously described in the literature. It is shown that the deformation at specific locations in the ear is significantly correlated to comfort issues reported by the hearing-aid users. In addition, this thesis presents an unpublished analysis that relates shape and deformation. This enables clinicians to identify hearing-aid users that have a higher risk of problem related to deformation. In addition, the work should provide valuable information that can be used in future designs of hearing aids.
Main Research Area:
Larsen, Rasmus, Olsen, Ole Fogh, Paulsen, Rasmus Reinhold
Technical University of Denmark, DTU Informatics, Building 321, 2009