Perception of Complex Auditory Patterns

This report describes research progress in three areas the perception of complex sounds, including tonal sequences and bursts of frozen gaussian noise models for the discrimination of complex sounds and the perception of speech sounds, under various degrees of stimulus uncertainty and levels of training. Major accomplishments during this period include the finding that the ability to detect very small frequency changes in single components of tonal sequences, previously assumed to be accomplished only after lengthy training on the specific discrimination task in question, is largely the result of familiarity with the stimulus and is relatively independent of the manner in which that familiarity was acquired the previously described PTD rule for auditory pattern discrimination predicts the discrimination of changes in temporal as well as spectral properties of patterns, and a new model of auditory pattern discrimination that combines elements of Jeffress leaky integrator and the Durlach-Braida equalization-cancellation models is quite successful in describing the results of noise-burst discrimination experiments, including the PTD phenomena mentioned above.