A series of measurements were performed to compare the performance of handsets and supra‐aural and ear‐insert‐type headsets on standard and modified couplers, and on the KEMAR ear simulator. These measurements have yielded data enabling comparisons to be made of the frequency response of earphones referred to the same location in the ear, at the eardrum, The effects of ear canal resonances on the upper frequencies, as well as the effect of the imperfect seal that the earphone makes with the ear on the receiver's low‐frequency response, are thus evidenced. One of the measured effects of the imperfect seal is a reduced low frequency response. The other measure of effect is leakage of room noise into the ear covered by the headphone. These effects are related to a lowering of speech transmission quality ratings as the room noise is increased, where headset types are differentially affected. Finally, data will be presented on the equivalent free‐field SPL's to SPL's measured at the eardrum for the various headset types.