Little, if any, work has explicitly addressed independence in the perception of complex sounds. General Recognition Theory provides a powerful framework in which to address such issues. Two experiments were carried out to test within-stimulus, between-stimulus, and decision-related notions of independence in two stimulus sets. One set consists of broadband noise stimuli varying in frequency and duration, the other harmonic tone complexes varying in fundamental frequency and spectral shape. Stimulus presentation likelihood was manipulated to enable hierarchical model fitting, which in turn provides powerful new tests of independence. The model fitting analyses indicate that decision-related independence (decisional separability) holds for all participants with each stimulus set, that within-stimulus independence (perceptual independence) holds and between-stimuli independence (perceptual separability) fails for all participants with the noise stimuli, and that both perceptual independence and perceptual separability fail for participants with the harmonic stimuli. |