The auditory pathways begin with sound being received by the cochlea and transmitted via the auditory nerve to the cochlear nucleus in the brainstem. Two thirds of auditory information crosses to the superior olivary complex in the opposite hemisphere. It then travels to nuclei in the pons and midbrain regions before reaching the medial geniculate body of the thalamus. From there it is distributed to the auditory cortex in the temporal lobes for higher level sound processing.

1. Auditory pathways of the Brain
Once sound information has been
received by the auditory (VIIIth)
nerve, there can be no further
information added to the stimulus.

2. Auditory pathways of the Brain
• Cochlear Nucleus
Each ear has a cochlea and an
auditory VIIIth nerve which transfers
the sound from the cochlea to the
Cochlear Nucleus.

3. Auditory pathways of the Brain
• Cochlear Nucleus
It is located at the junction of the
Pons and Medulla in the brainstem.

4. Auditory pathways of the Brain
• Cochlear Nucleus
Two thirds of the auditory information
received moves through the trapezoid
body of the brainstem into the
superior olivary complex of the
opposite hemisphere of the brain.

5. Auditory pathways of the Brain
• Superior Olivary Complex
They are located in the Medulla area
of the brain. (each ear has one)

6. Auditory pathways of the Brain
• Brainstem
The brainstem consists of three
structures. They are:
1. The Medulla
2. The Pons
3. The Midbrain

7. Auditory pathways of the Brain
• Nucleus of Lateral Lemniscus
They are located in the Pons region
of the brainstem.

8. Auditory pathways of the Brain
• Inferior colliculus
They are located in the midbrain area
of the brainstem

9. Auditory pathways of the Brain
• Thalmus
It is the major distribution center for
sensory activity of the brain.
It is located in the diencephalon
which lies superior to the midbrain.

10. Auditory pathways of the Brain
• Thalmus
This is where the medial geniculate
body is located. From this body, the
neural pathway “fans out” toward the
auditory cortex of each temporal lobe.

11. Auditory pathways of the Brain
The neural pathways divide into two
described paths. They are:
1. The ipsilateral path (same side)
2. The contralateral path (opposite side)

12. Auditory pathways of the Brain
Please refer to the hierarchy travel
diagram of the auditory neural
pathway as described on page #95 of
Lass & Woodford.
Please keep in mind, this pathway is
for each ear.

13. Auditory pathways of the Brain
• Auditory brain reception areas
There are two behavioral areas
where sound information is
processed. They are:
1. The brainstem
2. The auditory cortex

14. Auditory pathways of the Brain
• Brainstem Processing
This behavioral auditory reception
area is where lower level processing
such as the perception of loudness
and pitch occur.

15. Auditory pathways of the Brain
• Auditory Cortex Processing
This is where high level auditory
processing behavior occurs such as
the understanding of speech, speech
in noise, and other complex signals.

16. Auditory pathways of the Brain
Please refer to Lass & Woodford
page #96 for some nice “landmark”
definition of the brain anatomy.