# Echo suppression and discrimination suppression aspects ofthe precedence effect **Opening (not a real abstract):** Echo suppression and discrimination suppression aspects of the precedence effect XUEFENG YANG and D. WESLEY GRANTHAM Vanderbilt University Medical Center, NashviUe, Tennessee The precedence effect is a phenomenon that may occur when a sound from one direction (the lead) is followed within a few milliseconds by the same or a similar sound from another direction (the lag, or the echo). Typically, the lag sound is not heard as a separate event, and changes in the lag sound's direction cannot be discriminated. The hypothesis is proposed in this study that these two aspects of precedence (echo suppression and discrimination suppression) are at least partially independent phenomena. Two experiments were conducted in which pairs of noise bursts were presented to subjects from two loudspeakers in the horizontal plane to simulate a lead sound and a lag **Authors:** [[XUEFENG YANG and D. WESLEY GRANTHAM]]