There are two research areas in the Auditory Neuroscience Lab: Behavioral and physiological mechanisms of binaural and spatial hearing.
The goal of our research is to understand the neural mechanisms of auditory perception with particular emphasis on how sources of sounds are localized. Because the peripheral receptors of the ear have no mechanism to directly sense sound location on their own (unlike the topographic organization of the retina), location must be computed at more central levels. This makes sound localization a fascinating neurocomputational problem, particularly from a developmental perspective. Our experiments seek answers to at least four basic questions:
We use a multidisciplinary approach to tackle these questions employing both experimental and theoretical techniques including human and animal psychophysics, extracellular physiology, signal detection and information theory, systems identification techniques, acoustic transfer function measurement and modeling, digital filter design and estimation, acoustic signal design, and physiological systems modeling.
This research tackles clinically-motivated questions regarding the efficacy of and clinical approaches to mechanical stimulation of the ossicular chain and/or round window of the cochlea using active middle ear implantable hearing aids (AMEIs). The research is a collaboration between basic auditory science (Dan Tollin lab) and clinical otology (Herman Jenkins). Current research is examining the effect on device performance several variables affecting the mechanical loading of AMEIs on the round window of the cochlea, such as the area of the round stimulated, the physical loading pressure or force, the angle of approach to the round window, and intervening fascia materials. Similar studies will be conducted for stimulating different positions along the ossicular chain. These studies will establish a set of variables for optimal, and surgically feasible, placement of AMEIs on the RW and/or ossicles.
Behavioral and physiological mechanisms of binaural and spatial hearing
Basic studies of implantable auditory prostheses
Daniel J Tollin, PhD
Assistant Professor, Department of Physiology & Biophysics
Kanthaiah Koka, PhD
Tsai JJ, Koka K and Tollin DJ (2010). Roving overall sound intensity to the two ears impacts interaural level difference discrimination thresholds by single neurons in the lateral superior olive, J. Neurophysiol. 103:875-886.
Tollin DJ and Koka K (2009). Postnatal development of sound pressure transformations by the head and pinnae of the cat: binaural characteristics, J. Acoust. Soc. Am. 126:3125-3136.
Tollin DJ, Koka K, and Tsai JJ (2008). Interaural level difference discrimination thresholds for single neurons in the lateral superior olive, J. Neurosci. 28:4848-4860.
Tringali S, Koka K, Deveze A, Holland NH, Jenkins HA, and Tollin DJ (2010). Round window membrane implantation with an active middle ear implant: Effects on performance of round window exposure and transducer tip diameter, Audiology & Neurotology 15:291-302.
Lupo JE, Koka K, Holland NJ, Jenkins HA, and Tollin DJ (2009) Prospective Electrophysiologic Findings of Round Window Stimulation in a Model of Experimentally-induced Stapes Fixation, Otology & Neurotology, 30:1215-1224.