The auditory pathway is the central nervous part (" central hearing ") of the auditory system in humans and animals. The auditory system (synonym: auditory system ) is one of the sensory systems and is responsible for auditory perception , hearing. All information present in the sound is processed and evaluated in the auditory system. The auditory pathway consists of ascending and descending nerve tracts and core areas ("auditory nuclei ") that are integrated into them.
In land-living animals, airborne sound is first transmitted from the air medium to the fluid-filled inner ear. There the mechanical energy is converted into electrical energy in the inner hair cells (this process is called mechanoelectric signal transduction ) and then conducted in the axons of the auditory nerve in the form of action potentials into the brain .
In humans and other mammals, the auditory pathway begins at the sensory cells of the inner ear , which stimulate nerve cells via glutamatergic synapses , whose cell bodies are located in the spiral ganglion . These nerve cells are part of the auditory nerve. In it, the fiber systems lead to the nuclei cochleares (= snail cores), which are located in the medulla oblongata (part of the brain stem ).
Some of the fibers continue directly to the inferior colliculus on the same side (ipsilateral) in the midbrain. The mass of the fibers is led as the corpus trapezoideum, with partial interconnection in the upper olive nucleus complex , to which the nucleus corporis trapezoidei (English Medial nucleus of the trapezoid body , MNTB) belongs, from the equilateral (ipsilateral) to the mutual (contralateral) hemisphere side and grows there as Lemniscus lateralis to the inferior colliculus.
In the upper olive stone complex , transit time differences or transit time differences ( Interaural Time Difference , ITD) and intensity differences or intensity differences ( Interaural Level Difference , ILD ) between the two ears are evaluated in parallel so that the direction of a sound source can be located.
In the lemniscus lateralis, further nerve cells are switched in the nuclei lemnisci lateralis . There and in the inferior colliculi, some of the fibers cross back to the opposite side.
From the inferior colliculus, the fibers are to the medial geniculate body in the diencephalon passed, the interconnected for the last time, and as acoustic radiation, which the short posterior by the Crus internal capsule extends, the auditory cortex in the temporal lobes are fed.
Several side crossings and side couplings ( commissures ) of the auditory fibers enable directional hearing and the addition of possibly incomplete information to the individual ears.
From the upper olive complex, fibers are sent back to the inner ear (via the vestibulocochlear nerve , the eighth cranial nerve ), where they modulate the sensitivity of hearing. These fibers mainly end in the outer hair cells.
- The road of traveling waves (PDF file at www.uak.medizin.uni-tuebingen.de)  (PDF; 4.5 MB)
- Anatomy of the auditory pathway. Beautiful 3D representations 
- Hearing: how does it work? 
- Manfred Spitzer : Music in the head: hearing, making music, understanding and experiencing in the neural network , Schattauer, 2002. ISBN 3-7945-2427-6