“…One method has been the addition of a certain amount of white noise to the audio stimulus (Gat & Keith, 1978;Gradman & Spolsky, 1975); another has been complicating the syntactic form of the input (Cook, 1975(Cook, , 1977Forster, 1970). A third method reduces part of the signal itself: A study by Henrichsen (1984) compared the effects of contraction and reduction in oral English on native and normative listening comprehension, and a final group of studies reduces the presentation time of the signal (Aaronson, Markowitz, & Shapiro, 1971;Forster, 1970;Wingfield & Nolan, 1980). Taken as a whole, all of these studies have stressed the two-way interaction of the comprehension process.…”