1. The Auditory Nervous System
SPA 4302
Spring 2007

4. The Ascending Auditory Pathway
Primary Auditory Cortex
Medial Geniculate Body
Inferior Colliculus
Lateral Lemniscus
Superior Olivary Complex
Cochlear Nucleus
VIIIth Nerve

5. The Descending Auditory Pathways
Olivo-cochlear Neurons
Cortical Neurons
Innervation of Middle Ear Musculature

6. Olivo-Cochlear Efferent Neurons
Map of Auditory Efferents

7. Descending Pathways from Auditory Cortex
Descending neurons from Auditory Cortex, MGB, and IC

8. Efferent Innervation of Tensor Tympani & Stapedius Muscles
Innervation of middle ear musculature.

9. Development: VIIIth N. and Central Auditory Nervous System
VIIIth nerve initially: days 25 to 45
Spiral Ganglion, Vestibular Ganglia identifiable by day 35
Little else known about dev. of CANS

10. Hearing Loss and the CANS
VIIIth N: some SNHL, some normal
Tinnitus!
Unilateral SNHL, Initially high frequency
Possibly poor Word Recognition
Facial Nerve Symptoms
Disorders of the Auditory Nerve
Vestibular Schwannoma
Neuritis
Multiple Sclerosis
Auditory Neuropathy: a new dx category
Normal OAEs, Abnormal ABR

11. Disorders of the Cochlear Nuclei
Kernicterus:
Result of Rh incompatibility
Hyperbilirubinemia
Cerebrovascular Accident: A brainstem stroke
Congenital trauma, malformation
Pressure (trauma, increased CSF pressure)
Syphilis
Aging

12. Disorders of the Higher Auditory Pathways
Brainstem Tumors:
Intra-axial: contralateral or bilateral deficits
Extra-axial: ipsilateral deficits
Higher level lesions
CVA/Stroke/Aneurysm
produce contralateral deficits

13. Tests for Auditory Processing Disorder
PI-PB
Filtered Speech
Speech with Competition
SSI
Competing Sentence Tests
Dichotic Digits Test
Staggered Spondaic Word Test
Masking Level Difference Test

14. Therapeutic Management
Classroom Modifications
Improve Signal To Noise Ratios
Pre-Teaching
Remediation Activities
Listening “Games”
Computer Based Auditory Training
Compensatory Strategies
Homework Buddy