Optimization strategies for elderly hearing aid user satisfaction based on the Kano QFD integrated model and FAD theory

Advancements in global healthcare and declining birth rates have accelerated population aging, intensifying challenges such as workforce shortages and increasing the demand for tailored solutions to enhance the quality of life for the elderly. This study addresses a critical gap in the design of smart products for seniors by proposing a two-stage user satisfaction framework that integrates the Kano model, Quality Function Deployment (QFD), and Fuzzy Axiomatic Design (FAD) to manage uncertainties in user evaluations. Using a case study of Senior Hearing Aids (SHAs), the framework identifies nine key design factors and prioritizes improvements based on Importance Coefficients (ICs): environmental mode audio noise reduction (FR₇, IC = 0.9140), battery systems (FR₄, IC = 0.3416) for extended usage, and lightweight structure (FR₃, IC = 0.3219) for comfort. Secondary improvements focus on modular design (FR₅) and audio components (FR₆) to ease maintenance and enhance sound clarity. Lower-priority features, such as simple button interaction and easy-to-remove components, are optimized through integrated design strategies. Uncertainty analysis using FAD, combined with expert validation, demonstrates the framework's practicality and offers a scalable approach for aging-focused product design, with broader implications for smart healthcare innovations.