Anthropometric Studies of 3d External Ear and Auditory Canal for Hearing Protectors’ Fitting Use

Occupational noise still remains one of the most prevalent occupational health and safety problems, despite the efforts of International Labour Organization (United Nations) and Council of Labor Affairs (Nation). Hearing protectors are very important in providing proper protection for workers’ hearing ability in noisy working environments. However, the protection efficiency of wearing hearing protectors depends heavily on whether it is fitting inner or outside the ear. Three-dimensional (3D) surface anthropometry enables us to extend the study to 3D geometry and morphology of mainly external human body tissues. The fitting use of helmets, eyewear and facemasks are very dependent by using 3D head and face anthropometric data. But, few studies explore the relationship between hearing protectors and 3D external ear and auditory canal data. This project uses the portable 3D Camera M300 system (LT3D FaceCam 300) to collect 3D external ear and auditory canal data. During the three-year study periods, we will collect 150 pair ears with normal hearing functions. Their ages are between 20-40 years old. In the first year, it will collect 60 pair ears (30 males, 30 females). Our team will study the 3D external ear and auditory canal size and features, and category the data by the clustering validity index. In the second year, it will collect 60 pair ears (30 males, 30 females). We will study the 3D external ear and auditory canal shape and features, and category the data by the principle component analysis. In the third year, it will collect 30 pair ears (15 males, 15 females). We will integrate the data of size and shape, and apply in the computer-aided design for the hearing protectors’ design. And it will verify the fitting rate by the mean absolute difference. The expected results of this three-year proposal are: (1) Build and validate 3D external ear size categories and representatives. (2) Build and validate 3D auditory canal size categories and representatives. (3) Build and validate 3D external ear shape categories and representatives. (4) Build and validate 3D auditory canal shape categories and representatives. (5) Compare the differences of CAD ear muffs and 3D external ear representatives. (6) Compare the differences of CAD ear plugs and 3D auditory canal representatives. (7) Suggest and apply to hearing protectors’ regulations, standards and design guidelines.

Project ID:PB10108-2819
External Project ID:NSC101-2221-E182-005-MY3