1. Oregon Health & Science University
Psychological and Physiological Acoustics The encoding and interpreting of sound energy by biological systems
Frederick J. Gallun, PhD
National Center for Rehabilitative Auditory Research Portland VA Medical Center
and
Oregon Health & Science University

3. Hearing Research is Multidisciplinary
Physiology
Psychology
Acoustics
Audiology
Engineering
Computer
Science
Statistics
Animal
Bioacoustics
Speech
Music

4. The investigation and the dissemination of information about psychological and physiological responses to sound in humans and other species
Areas of interest include, but are not limited to:
Perception and perceptual organization of simple and complex sounds, including speech
Anatomy and function of the auditory pathways, including all physical and biological responses to auditory stimulation
Hearing disorders, hearing loss, and auditory prostheses
Vibrotactile and vestibular sensation, and the interaction of hearing with other sensory modalities
Developmental, aging, learning and plasticity effects in auditory function
Theories and models of auditory processes

7. Filtering a pure tone
Amplitude
Time
Low Frequency High Frequency

8. Functions of the Central Auditory System
Thalamus:
Organization and updating of cortical-brainstem connections
Inferior Colliculus:
Coding of basic timing and frequency patterns
Superior Olivary Complex:
Spatial Processing
Cochlear Nucleus:
Timing and frequency extraction

9. Functions of the Central Auditory System
Frederick Gallun, PhD Anna Diedesch, AuD
5/21/2010
Functions of the Central Auditory System
Corpus Callosum:
Transfer information between left and right hemispheres
Frontal Cortex:
Control of attention, task-dependent activity, and plasticity of the system over time.
Parietal Cortex:
Spatial information
Auditory Cortex:
Feature-specific processing of auditory information

10. The Hearing Aid
Hearing aids amplify sounds in the frequency regions where sensitivity is impaired.
Modern hearing aids are small and powerful – and expensive.
While very effective at the job it does, the hearing aid is still only able to provide rehabilitation for peripheral dysfunction.

11. The Cochlear Implant
Cochlear implants are the only devices currently in wide clinical use that replace sensory input with direct electrical stimulation.
An electrode inserted into the cochlea uses electrical pulses to stimulate the auditory nerve, which then fires in temporal patterns matching the input sounds.
With as few as four to eight independent channels of stimulation, many users can learn to understand speech well enough to speak on the telephone.

12. Challenges to Restoring Hearing via Cochlear Implants
Recreating ‘normal’ temporal activity in the auditory nerve
Providing good electrical separation between neighboring electrodes
Courtesy of R. V. Shannon, House Ear Institute, Los Angeles, MA

13. Future Technology: The Brainstem Implant
A large number of clinical trials have already been conducted that demonstrate the ability of cochlear nucleus implants to provide auditory input to patients with damage to the auditory nerve.
Some patients with damage to the cochlear nucleus have even had implants inserted that stimulate the inferior colliculus.

14. Featured Sessions and Talks in Salt Lake City