ASA 127th Meeting M.I.T. 1994 June 6-10

4pPP19. Repetition detection by untrained listeners presented with very long period recycled noises.

Psychol. Dept., Univ. of Wisconsin---Milwaukee, Garland Hall, Milwaukee, WI 53201

In 1963 Guttman and Julesz reported that repetition of noise segments could be detected effortlessly for periods up to 1 s, and with difficultly up to 2 s. Bashford et al. (1992) reported that initial cross-modal cueing (100-ms flash, synchronous with a fixed portion of the waveform) allowed experienced listeners to exceed easily this 2-s limit of repetition detection. The present experiment examined whether prior flash cueing would enable untrained listeners to tap in synchrony with the previously highlighted portion of recycled noise segments (RNs) having periods from 2 to 10 s. Accurate synchronous tapping to 10-s RNs was achieved in 48% of the trials. Surprisingly, it was also observed that, without prior cueing, a separate group presented with the same 10-s RNs tapped accurately at a fixed waveform position on 32% of the trials. While taps of the cued group clustered around the previously highlighted positions, taps of the uncued group were distributed randomly. These results indicate that repetition detection by naive listeners is possible well above the two second limit described by Guttman and Julesz (1963). [Work supported by NIH.]