Frequency discrimination of complex tones; assessing the role of component resolvability and temporal fine structurea)
The top and middle rows illustrate the effect of component phase on the waveforms of three-component complex tones. The top-left trace shows the waveform of a cosine-phase stimulus (the 9th, 10th, and 11th harmonics of a F0) and the top-right trace shows a simulation of the waveform evoked by that stimulus on the basilar membrane at the place tuned to , calculated as described by Alcántara et al. (2003). The middle two traces show corresponding waveforms for an alternating-phase stimulus. The lower two traces simulate basilar-membrane waveforms evoked by 11-component stimuli similar to those used by Houtsma and Smurzynski (1990). The tones contained harmonics 9–19 of a F0. For the bottom-left trace, the components were added in sine phase. For the bottom-right trace, the components were added in Schroeder-negative phase.
Individual and mean (bottom-right) results for experiment 1 (harmonics centered at ). F0DLs, expressed as a percentage of , are plotted on a logarithmic scale as a function of the average number, , of the lowest harmonic. Open and filled circles show results for components added in cosine phase and alternating phase, respectively. Error bars in the results for individual subjects show ± one standard error (SE) of the mean across repeated runs. Error bars in the mean results show ± one standard error (SE) of the mean across subjects. The dashed lines show the smallest F0DLs that could be achieved if performance were based on discrimination of the frequency of the lowest harmonic in the complex tones.
As Fig. 2, but showing the results for experiment 2 (harmonics centered at ).
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