In 1953, Cherry found that a subject can repeat virtually all of a continuous message that is switched alternately to his left and right ears, except at certain critical rates of alternation around 3 cps. The experiments reported here investigated the effect described by Cherry. In the first experiment, the intelligibility of continuous speech was measured as a function of rate of alternation, which ranged from 1–16 cps. Two such functions were measured, one using normal speech and the other using the same speech played back at slightly increased speed. Comparison of the two functions shows that, when the playback speed of the speech was increased, the rate of alternation that gave subjects most difficulty also increased by the same factor. Therefore, the effect cannot be ascribed to any processing time, etc., that is independent of the speech, but must occur because the speech reaches each of the listener's ears in segments, as a result of which some portions of the speech wave arrive in such a form that he cannot extract the cues from them. A second experiment compared the words that were correctly repeated by subjects who heard alternated speech with the words that were identified by subjects who heard only the signal for the left ear (interrupted speech) and the words that were identified by subjects who heard only the signal for the right ear (also interrupted speech, but complementary to the left‐ear signal). It was found that the performance of subjects repeating alternated speech can be adequately described as the sum of the performances of the two groups of subjects who repeated interrupted speech, at all rates of alternation, if allowance is made for the additional context available to the alternation subjects, who heard both the left‐ear signal and the right‐ear signal, one in each ear.