A developmental process, independent of morphogenetic (shape) change, that is required for the superior olivary nucleus to attain its fully functional state. The superior olivary nucleus is a small cylindrical mass on the dorsal surface of the lateral part of the trapezoid body of the pons, and it is situated immediately above the inferior olivary nucleus. It receives projections from the cochlear nucleus and thus is involved in the perception of sound. [ GOC:dgh http://purl.obolibrary.org/obo/go/references/0000021 GOC:jid https://www.worldcat.org/search?q=bn%3A0838580343 GOC:dph GOC:cls ]