Hearing aids; part 3: hearing aids equipment not entirely worn on the listener

This specification outlines technical requirements for hearing aid devices that are designed to be worn only partially on the user's head. It addresses the specific design, safety, and performance criteria necessary for devices that do not fully enclose the head or ear canal, ensuring they function effectively in various environments. The document covers aspects related to acoustic output, electrical safety, and physical dimensions to guarantee that these partial-wear devices provide adequate sound amplification without causing harm. It establishes testing methods to verify that the equipment meets the intended functional standards for users who require hearing assistance but may need a form factor that is less intrusive than full-head models. The guidelines also include provisions for labeling and user instructions to ensure proper operation. This standard serves as a reference for manufacturers and regulatory bodies to align product development with established technical benchmarks for this specific category of assistive listening equipment.