Central auditory onset responses, and temporal asymmetries in auditory perception

• Published in: Hearing research Vol. 167; no. 1; pp. 192 - 205
• Main Authors: Phillips, D.P, Hall, S.E, Boehnke, S.E
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-05-2002; Elsevier
• Subjects: Acoustic Stimulation; Adaptation, Physiological; Animals; Auditory Cortex - physiology; Auditory Pathways - physiology; Auditory Perception - physiology; Auditory temporal asymmetry; Auditory Threshold - physiology; Biological and medical sciences; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Fundamental and applied biological sciences. Psychology; Humans; Offset response; Onset response; Perception; Single unit; Time Factors; Vertebrates: nervous system and sense organs; Offset response; SPL, sound pressure level; Single unit; Auditory temporal asymmetry; ABR, auditory brainstem response; Perception; CF, characteristic frequency; Onset response; Human; Hearing; Acoustic stimulus; Asymmetry; Noise; Central nervous system; Sensorial perception; Auditory pathway; Laterality; Brain (vertebrata); Adaptation
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(02)00393-3

Historically, central auditory responses have been studied for their sensitivity to various parameters of tone and noise burst stimulation, with response rate plotted as a function of the stimulus variable. The responses themselves are often quite brief, and locked in time to stimulus onset. In the stimulus amplitude domain, it has recently become clear that these responses are actually driven by properties of the stimulus’ onset transient, and this has had important implications for how we interpret responses to manipulations of tone (or noise) burst plateau level. That finding was important in its own right, but a more general scrutiny of the available neurophysiological and psychophysical evidence reveals that there is a significant asymmetry in the neurophysiological and perceptual processing of stimulus onsets and offsets: sound onsets have a more elaborate neurophysiological representation, and receive a greater perceptual weighting. Hypotheses about origins of the asymmetries, derived independently from psychophysics and from neurophysiology, have in common a response threshold mechanism which adaptively tracks the ongoing level of stimulation.