The contribution of intrinsic amplitude modulation to the precedence effect at high frequencies Bernhard U. Seeber The precedence effect (PE) demonstrates our ability to locate sounds correctly at the source despite the presence of interfering sound reflections. It was shown to function with long duration broadband noises even when lead and lag had simultaneous onsets, i.e. with information restricted to the ongoing sound part. The present study investigated if the PE can be elicited even for high frequency sounds based on intrinsic envelope modulation. This is questionable because a) the main cues for localization, interaural time differences extracted from the temporal fine structure, are not available, b) inherent amplitude modulation provides only a weak cue for sound segregation via pitch mechanisms. In a localization dominance task participants indicated the perceived location of lead-lag stimuli. Stimuli were harmonic complex tones (HCT) and Gaussian noise bandlimited to 2500-5500 Hz. Preliminary results showed that the PE exists for these stimuli and the amount of intrinsic modulation affected echo thresholds (ETs). ETs were 1.5 ms larger for HCTs with Schroeder positive than negative phase. Localization dominance was weaker for Gaussian noise and a single, broad image was frequently heard. Stimuli with brief onsets (1 vs. 50 ms) showed roughly 1 ms longer ETs.