Cognition, 4 (1976) 155-176 @Elsevier Sequoia S.A., Lausanne - Printed in the Netherlands 2 What’s what: talkers help listeners hear and understand by clarifying sentential relations* VIRGINIA VALIAN CUNY Graduate Center, New York ROGER WALES University of St. Andrews Abstract It was predicted that a talker would clarify the sentential relations of an utterance if a listener indicated difficulty in hearing and understanding. Subjects read syntactically clear and distorted sentences to a listener (cxperi- rnenter) in un adjoining room. The experimenter often asked “What?” Subjects changed distorted versions to clear versions, while repeating clear versions essentially as first read. Other subjects were asked to make the sentences clear and simple to understand. The same basic results were obtained. Talkers thus seem to interpret a “What?” part1.y as a request for clearer sentential relations und respond accordingly. The results indicate that talkers have knowledge of underlying structure. Several alternate explanations can be rejected. A relative derivational theory of complexity, is presented. The present experiment systematically explores the talker’s knowledge and use of syntactic structure within the context of an everyday speech situa- tion. Every talker has experienced the phenomenon of saying something to someone who is having difficulty both hearing and understanding what has been said. This can occur, for example, in a noisy restaurant, or when the talker and listener are in different rooms. Listeners commonly signal their difficulty by asking “What?” The talker must then decide how, if at all, to *The experiments were begun while the senior author was Research Associate and the junior author Visiting Professor at the Psychology Department, Massachusetts Institute of Technology, and supported in part by the Public Health Service, Grant No. MD 0516844 to M.I.T.; we particularly thank M. Garrett for his help. The research was also supported by a grant from the City University of New York I:nculty Research Award Program. R. I:iengo and D. T. Langcndoen pave linguistic advice; L. Goldstein helped with the apparatus.