7.4 Summary of Section 7
Fibres of the cochlear nerve synapse on the cells of the cochlear nuclear complex which is the first station of the central auditory pathway. From here signals are sent to the superior olivary complex, the inferior colliculus, lateral lemniscus, medial geniculate nucleus and finally the auditory cortex. The central role of the auditory cortex is the processing of complex sounds.
Each cochlear nuclear complex receives input from only one ear. In the cochlear nuclear complex are several different neural types that are responsible for extracting information about the spectral and temporal features of incoming sound.
Neurons in the superior olivary complex (SOC) are the first to receive input from both ears and are thought to play an important role in sound localization. The SOC processes information about interaural delays and intensities.
The inferior colliculus (IC) is a site for convergence of information. IC cells are organized in layers called sheets and within each sheet there appears to be a segregation of the EE and EI inputs. More complex aspects of a sound signal are processed in the IC and further features are extracted.
A tonotopic representation of frequency is seen at all levels of the auditory pathway.