Defines the electrical, marking and safety characteristics of a circuit for an external electrical input to a personal hearing aid for compatibility with external electrical or electroacoustic signal sources. Excludes the interconnection of the parts of a CROS (contralateral routing of signals) or Bi Cros hearing aid, when designed as a complete system. Includes mechanical characteristics of plug and socket for electrical input, marking of electrical input, and electrical safety. BS AMD 10314 RENUMBERS THIS STD