Fig. 10.

Schematic of the crossed and uncrossed reflex pathways for sound-evoked MOC feedback to 1 ear. Cochlear nucleus neurons on each side project to MOC cells on the opposite side of the brain (bold arrows), which drives their responses to monaural sound in the dominant ear: 2/3 of the MOC neurons projecting to each ear are driven by ipsilateral sound (black), while only 1/3 are driven by contralateral sound (gray). The binaural facilitation of MOC neurons by sound from the nondominant ear is schematized by the smaller, paler arrows to each MOC cell cluster. Cuts to the dorsal surface illustrate why a midline cut interrupts only the ipsilaterally responsive MOC neurons whereas a side cut can interrupt both ipsilateral and contralateral reflexes. LSO, lateral superior olive; MSO, medial superior olive.