Experimental design. The experiment consisted of three sessions in which the subjects were presented with acoustically distorted sentences (Session 1), followed by undistorted sentences (Session 2), after which the distorted sentences were presented once again (Session 3). After each sentence, the subjects indicated whether they had understood the sentence by pressing a Yes/No response key.
Tiitinen et al. BMC Neuroscience 2012 13:157 doi:10.1186/1471-2202-13-157