Introduction to Human-Product Interaction, Comfort Perception, and Ear Anthropometry

Human-cantered design has become a central paradigm in contemporary engineering and product development, driven by advances in computation, sensing, and wearable technologies. Comfort, as a key determinant of user experience, plays a critical role in evaluating and optimizing human-product interaction. Ear-related wearable devices represent a rapidly expanding category within head-face wearables, evolving from simple audio interfaces into multifunctional systems that support communication, noise regulation, hearing assistance, health monitoring, and biometric sensing. Despite their widespread use, ergonomic research focusing specifically on the external ear remains limited, creating challenges for comfort-oriented design and evaluation. Human-product interaction is shaped by the combined influence of user characteristics, product attributes, and interaction processes. Established interaction experience models provide complementary perspectives for understanding how perception, cognition, and physical exposure contribute to user outcomes. Comfort is inherently multidimensional, encompassing physical, psychological, physiological, and environmental components, with physical comfort serving as the most direct and measurable indicator in wearable contexts. Ear anthropometry offers essential quantitative foundations for ergonomic design by capturing variability in ear size, shape, and population characteristics. Together, these perspectives establish a theoretical and methodological framework for analysing comfort mechanisms and supporting evidence-based design of ear-worn wearable technologies.