Table 3.

Questionnaire development process.

Process	Details
Primary source	Developed based on the research project “Development of Human Enhancement Technology for Auditory and Muscle Support” (2017–2019).
Literature review	Analyzed existing research on music perception, learning experiences, and preferences.
Expert review/FGI	Conducted on August 1, 2020, to refine readability, response format, and questionnaire structure. Consulted 3 specialists with over 8 years of experience in audiology, speech therapy, and music therapy. Validated questionnaire appropriateness and content. - J. H. Kim, Ph.D. in Audiology: Clinical audiologist specializing in hearing aid technology and auditory rehabilitation in the Department of Otorhinolaryngology at Hallym University Sacred Heart Hospital - Y. J. Lee, M.A. in Speech-Language Pathology: Speech-language pathologist at Chungeum Rehabilitation Center - J. H. Chang, M.A. in Clinical Music Therapy: Music therapist at Samsung Sorimom Child Development
Final validation	Reviewed by a professor specializing in social work with individuals with disabilities and validated the final questionnaire, ensuring its relevance to the target population and applicability in social work and rehabilitation settings.

FGI = focus group interview.