Discrimination of fundamental frequency (F0) of complex tones can be impaired substantially by the presence of another complex (the "fringe") immediately before and after the target complex. This has been attributed to listeners over-integrating information about the fringe-F0 when estimating the target-F0. It has been shown (Micheyl & Carlyon, 1998) that for the impairment to occur (i) target and fringes have to be in the same frequency region; (ii) if all harmonics of target and fringes are unresolved by the peripheral auditory system then they may differ in F0; otherwise, they have to be similar. The present experiments investigated the effect of lateralized fringes. In a 2I-2AFC adaptive procedure, difference limens for F0 for a 100-ms harmonic target complex were measured in the presence and absence of 200-ms harmonic fringes. The nominal F0 was 88 Hz or 250 Hz. Stimuli were bandpass filtered between 125-625 Hz, 1375-1875 Hz, or 3900-5400 Hz. The target was presented monaurally, while the fringes were monaural (ipsilateral or contralateral relative to the target) or binaural (diotic or dichotic, lateralized by interaural level difference or interaural time difference). Results showed reduced effects of fringes localized away from the target, the exact size depending on the resolvability of the components and their specific lateralization. Work supported by Wellcome Trust.
Poster in der Gruppe Wahrnehmung und Aufmerksamkeit I, Montag, 29. März 1999, 17:00-19:00, Foyer 2. Stock
