"More than ________nerve fibers from the Organ of Corti join together to form the auditory nerve."
The nerve fibers extend about ____ _______from the cochlea through the skull before they enter the brain.
"Once the auditory pathway from each ear reaches the brain, it is organized much like two ________ railway systems running between the same cities with each having its own _______terminals."
"The auditory nerve feeds into the __________ __________, the fist terminal in the auditory pathway."
The end of the line for the ________ ___________ is the cochlear nucleus, so at this level, low in the brainstem, all neural auditory impulses "transfer" to the ascending __________ _______.
auditory nerve, auditory pathway
The transfer point between one nerve cell and another is called a _________.
The ascending auditory pathway extends to the ________ ________, one in each temporal lobe of the brain.
Between the cochlear nucleus and the auditory cortex are ____sets of terminals, one on each side of the brain stem.
The lowest and smallest set of terminals is the __________ ________. Here auditory information from _______ _____can be matched with information from the other.
superior olive, one ear
The auditory pathway extending from the level of the cochlear nucleus, and also the superior olive, to the next highest terminal is called the ___________ __________. At this level, each of the two terminals is called an __________ ________.
lateral lemniscus, inferior colliculus
The last terminal in the brainstem, where all auditory impulses transfer to auditory projection fibers if they are to reach the auditory cortex, is the _____________ ____________ ______.
medial geniculate body
The arrangement of the auditory pathway provides for the transfer of auditory neural impulses from one side of the brainstem to the other at what 3 levels?
cochlear nucleus, superior olive, and inferior colliculus.
With right-left ____________ at these levels, an auditory signal can ascend all the way to the medial geniculate body and auditory cortex on the same side (__________), or cross over to the opposite side (_______) at the cochlear nucleus, superior olive, or inferior colliculus.
interconnections, ipsilateral, contralateral
Although the "main line" is a __________ route from the ear on one side to the brain on the other, this can be a misleading impression of how the auditory system is "wired." In reality, inputs from _____ _____ are well represented on _______ _____ of the brain.
contralateral, both ears, both sides
The crossover in the auditory pathway permits comparisons of info ration about frequency, intensity, and time of arrival of the __________ ________ at the two ears. Were it not for these comparisons, we would be seriously hampered in ability to detect ________ of a sound and to focus attention in a noisy environment.
acoustic signal, direction
Nevertheless, the "main line" contralateral auditory pathway does make it slightly easier to __________ ________ better with the right ear than with the left; the main line from the right ear is to the left ________ _______, where the speech center is usually located.
understand speech, temporal lobe