It doesn’t get any more precise than this: Neurons in the medial superior olive (MSO) in many mammals, including humans, are sensitive to temporal differences between their synaptic inputs of only a few microseconds. These neurons are the basis for our ability to resolve even a 5-μs disparity in the time of arrival of a sound at each ear. This capacity enables humans to discriminate between temporally overlapping sounds based on spatial segregation, as for instance, at a cocktail party or a poster session at a scientific conference. This chapter aims at providing a comprehensive summary on the current state of research regarding the MSO, ranging from cellular and circuit anatomy to subcellular and channel physiology to spatial coding and perception. Consequently, the chapter is subdivided according to these thematic aspects. Nonetheless, while such subdivisions are helpful for providing structure to the reader, they can also convey the inter-dependencies between these topics: for example, when studying the spatial sensitivity of MSO neurons on the mechanistic level, it is crucial to also consider its anatomical specializations (on the subcellular and circuit level), as well as corresponding perceptional phenomena. Finally, the chapter suggests a complete picture of the MSO only emerges by including evolutionary considerations, that is, the phylogenetic origin of the many fascinating specializations that can be observed within the MSO circuit.