Tests on supraaural‐ and insert‐type earphones for telephone applications, designed from measurements with real ears and the American National Standards Institute (ANSI) 2‐ and 6‐cm3calibration couplers, are reported. Disagreements between real‐ear and coupler data are rationalized by reducing the basic 2‐cm3volume to 1.3 cm3and employing an approximate transfer characteristic to relate the supraaural coupler data to a common plane of reference corresponding to the tympanum position. Several experimental couplers for obtaining data within the telephone speech band, which permit measurements on the two types of earphone at the common plane, are described.