Lentz Jennifer J
Department of Speech and Hearing Sciences, Indiana University, 200 S. Jordan Avenue, Bloomington, Indiana 47405, USA.
J Acoust Soc Am. 2005 Nov;118(5):2794-7. doi: 10.1121/1.2062187.
Profile-analysis thresholds were measured in the presence and absence of overall level variation at different stimulus levels to determine whether nonlinear changes in the shape of the edges of excitation pattern peaks contribute to poorer spectral-shape sensitivity observed under roving levels. Roving levels decreased sensitivity for stimuli having few components separated widely in frequency to a greater extent than for stimuli having more densely spaced components. The stimulus level did not influence sensitivity when overall level variation was absent, suggesting that listeners rely on peaks in the excitation patterns and not the edges of the peaks (as would have been predicted by the near miss to Weber's law). Because the edges of the peaks were not used in the absence of roving levels, it follows that the larger rove effects for sparse stimuli were not likely due to excitation pattern inconstancy.
