From thisfirst synapse, there are numerous pathways with variable numbers of additional synapses which produce auditory-mediated reflexes and conscious perception of sound, ~ From this first synapse, there are numerous pathways with variable numbers of additional synapses which produce auditory-mediated reflexes and conscious perception of sound. - The lateral lemnisci [JTO]€CI to the caudal colliculi of the midbrain. ~ These brainstem pathways are characterized bya number of intervening relay nuclei in which axons may synapse and/or decussate within the system. The result of these multiple processing routes is that auditor)/rh formation from both cochleae reaches each caudal co//icu/us although the preponderance of input for each colliculus is from the contralateral cochlea. ~ The pathways for conscious perception oi sound arise primarily from the caudal colliculi, exiting each colliculusiia the brachium of the caudal colliculus to synapse within the primary thalamic relay nucleus for audition, the medial geniculate nucleus. ~ From here, fibers project to the primary auditory cortex located in the Sylvian and Ectosyliian gyri of the temporal lobe. Sound is not “perceived” at a conscious level until it reaches the sensory cortex