The standard describes air conduction hearing-aid measurement methods that are particularly suitable for specification and tolerance purposes. Among the test methods described are output sound pressure level (SPL) with a 90-dB input SPL, full-on gain, frequency response, harmonic distortion, equivalent input noise, current drain, induction-coil sensitivity, and static and dynamic characteristics of automatic gain control (AGC) hearing aids. Specific configurations are given for measuring the input SPL to a hearing aid. Allowable tolerances in relation to values specified by the manufacturer are given for certain parameters. Appendices are provided to describe an equivalent substitution method, characteristics of battery simulators, and additional tests to characterize more completely the electroacoustic performance of hearing aids.