Auditory Pathways Flashcards
What does frequency affect
The distance along the basilar membrane travelled by the wave
Where do high frequency sounds finish on the basiliar membrane
At a peak near the base
Where do low frequency sounds finish on the basilar membrane
At a peak near the apex
What does tonopy mean
The brain is able to distinguish a cord with lots of notes as they have distinctive peaks which the brain then has to be able to distinguish somewhere
What are cochlear implants used for
To restore some hearing
Who can cochlear implants be used in
People who have lost cochlear hair cell function, but in whom the sensory neurones of the spinal ganglion are still functional. Hair cells are damaged but the apical cells underneath are still intact
How do cochlear implants work
- A processor breaks down sound into its frequency components. 2. The different frequency channels are transmitted to the implant receiver. 3. The signal is conducted along wires that end up in electrodes in the cochlea. 4. The electrodes stimulate the nerve cells underneath the appropriate region of the basilar membrane
Where is the tonopic relationship of frequencies to position seen
Not only on the basilar membrane but at all levels within the auditory pathways- it is the principle on which cochlear implants work
What need to happen to axons when travelling to the brain
They need to be kept in order
What do axons descend in
Tracts called lateral lemniscus
What happens at the superior olivary nucleus in the medulla
There is an exchange of information from the left and right side of the brain which provides spatial sound awareness and judgment made on time and intensity of sound- stereophonics
What happens in the inferior colliculi in the midbrain
Controls visual and auditory reflexes e.g. hear a bang and turn to look where it came from. The reflex in the midbrain happens fast to rotate muscles in the neck, this occurs via the tip-toe spinal tract. The optic part of the brain occurs in the same part of the midbrain result in the reflex of turning to look at something that you see in your peripheral vision
What happens in the medial geniculate nucleus in the thalamus
Important in communication and control of information going to the cortex
Where is the primary auditory cortex
(Heschl’s gyrus) is tucked into the superior-medial surface of the temporal lobe. It has a tonotopic map of frequency
What do the auditory components of the brain do
Analyse pitch and language
What do the motor aspects of the brain do
Analyse rhythm
