Ear shape categorization for ergonomic product design

With the development of hardware technology, the interest in wearable devices is increasing. Among the associated technology, ear-related wearable devices provide an efficient communication experience for auditory-verbal interaction while the user is moving. Since wearable devices are attached to the body, a sense of fitness is an important element. Therefore, this study aims to improve wearability of ear-related wearable devices by analyzing and categorizing ear shapes of Koreans and Caucasians based on 3D ear data. To do so, first, the external ear was measured through a 3D scanner. Next, descriptive statistics and correlation analyses were performed for each anthropometric measurement. The ear measurements were then compared by race, gender, and age group through an independent two-sample t-test and one-way analysis of variance. Then, an exploratory factor analysis was performed to determine the major factors that characterize the ear shape. Finally, categorization of ear shapes according to race was conducted through a hierarchical cluster analysis. From this, the major factors affecting ear shapes were found to be related to upper ear height, concha width, lower ear height, and ear protrusion. From the extracted factors, ear shapes were categorized into four groups: round, rectangular, triangular, and inverted triangular. Resultingly, these four ear shapes should be considered in improving the wearability of the ear-related wearable device. Ultimately, these findings inform applications in the ear-related wearable device industry.