This monograph is an initial attempt to define listening as it will be measured in the TOEFL 2000 test, within the framework delineated in "TOEFL 2000 Framework: A Working Paper" (Jamieson, Jones, Kirsch, Mosenthal, and Taylor, 2000). This monograph is comprised of six sections. After a brief introduction, an overview of academic listening is presented, which outlines theory and research in the areas of listening in general and academic listening in particular. The third section describes theory and research on the variables that characterize academic listening and that might drive the difficulty of a listening task. The fourth section addresses technological issues for the listening section of the TOEFL 2000 test. A research agenda is presented in the fifth section of the monograph, and the final section describes the features that distinguish the TOEFL 2000 test from its predecessors.