title: Investigating temporal asymmetry using masking period patterns and models of peripheral auditory processing.
abstract: Two experiments were conducted in conjunction with modeling to evaluate the role of peripheral nonlinearity and neural adaptation in the perception of temporally asymmetric sounds. In both experiments, maskers were broadband noises amplitude modulated with ramped and damped exponential modulators that repeated at 40 Hz. Masking period patterns (MPPs) were constructed by measuring detection threshold of a 5-ms, 1000-Hz tone burst as function of the signal's onset delay. Experiment I showed that varying modulator half-life from 1 to 16 ms led to differences in the damped and the ramped MPPs that were largest at the short half-lives and diminished at the longer half-lives. When masker level was varied (experiment II), the largest difference between ramped and damped MPPs occurred at moderate stimulus levels. Two peripheral auditory models were evaluated, one a simple auditory filter followed by a power-law nonlinearity and another, a model of auditory nerve processing [J. Acoust. Soc. Am. 126, 2390-2412 (2009)] that includes neural adaptation. Neither models predicted differences between the ramped and damped MPPs, providing indirect support that the central auditory system has a role in perceptual temporal asymmetry.
authors.affiliation: Department of Speech and Hearing Sciences, Indiana University, Bloomington, Indiana 47405-7000, USA. jjlentz@indiana.edu
authors.forename: Jennifer J
authors.initials: JJ
authors.lastname: Lentz
authors.forename: Yi
authors.initials: Y
authors.lastname: Shen
mesh_terms: D000161:Acoustic Stimulation; D000222:Adaptation, Physiological; D001306:Auditory Pathways / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology; D006801:Humans; D008959:Models, Neurological; D009622:Noise; D046709:Pattern Recognition, Physiological / Q000502:physiology*; D010470:Perceptual Masking / Q000502:physiology*; D013997:Time Factors