<P> The superior olivary nucleus plays a number of roles in hearing . The medial superior olive (MSO) is a specialized nucleus that is believed to measure the time difference of arrival of sounds between the ears (the interaural time difference or ITD). The ITD is a major cue for determining the azimuth of sounds, i.e., localising them on the azimuthal plane--their degree to the left or the right . </P> <P> The lateral superior olive (LSO) is believed to be involved in measuring the difference in sound intensity between the ears (the interaural level difference or ILD). The ILD is a second major cue in determining the azimuth of high - frequency sounds . </P> <P> The superior olivary complex is generally located in the pons, but in humans extends from the rostral medulla to the mid-pons and receives projections predominantly from the anteroventral cochlear nucleus via the trapezoid body, although the posteroventral nucleus projects to the SOC via the intermediate acoustic stria . The SOC is the first major site of convergence of auditory information from the left and right ears . </P> <P> The superior olivary complex is divided into three primary nuclei, the MSO, LSO, and the Medial nucleus of the trapezoid body, and several smaller periolivary nuclei . These three nuclei are the most studied, and therefore best understood . Typically, they are regarded as forming the ascending azimuthal localization pathway . </P>

Auditory cells in the superior olivary nucleus receive their input from the