A new one‐piece earphone cushion, model 51, that should afford more reliable hearing measurement data than the conventional two‐piece MX‐41/AR earphone cushion, has been developed by Telephonics Corporation. In particular, the material used for the one‐piece cushion should be more stable over a long period of time than the sponge material used in the two‐piece MX‐41/AR cushion. In addition, the single material of the one‐piece cushion is more easily compounded and thus easier to control than those materials used in the two‐piece cushion, and the cementing operation required for the two‐piece cushion is avoided. The acoustical performances of the one‐ and two‐piece cushions mounted on a TDH‐39 earphone were compared by threshold‐loudness‐balance and coupler measurements. The comparison with threshold‐loudness‐balance measurements on ten subjects showed no significant differences with a confidence of 95% and coupler measurements showed differences less than 0.8 standard deviations in all cases (i.e., no significant differences with α=0.05). In summary, the one‐piece earphone cushion does not differ significantly in acoustical performance from the two‐piece MX‐41/AR cushion. In addition, there is a strong indication that the one‐piece cushion will afford more consistent performances between units, more long‐term stability, and better wearer comfort than the conventional MX‐41/AR cushion.