Contextual cues in selective listening

Two messages were presented dichotically and subjects were asked to "shadow" whatever they heard on one ear. Somewhere in the middle the two passages were switched to the opposite ears. Subjects occasionally repeated one or two words, at the break, from the wrong ear, but never transferred to it for longer than this. The higher the transition probabilities in the passage the more likely they were to do this. One explanation might be that the "selective filter" (Broadbent, 1958) acts by selectively raising thresholds for signals from the rejected sources rather than acting as an all-or-none barrier.