This paper reports on ongoing work related to the representation of hierarchical structures using multiple synthetic voices. We manipulated three synthetic voice parameters, average pitch, pitch range and speech rate, to represent nodes in a hierarchy. We created hierarchies containing 10 nodes and three levels deep. A within-subjects design (N=12) was conducted to compare the effect of multiple synthetic voices to single synthetic voices for locating the positions of items in a hierarchy. Subjects were trained with the set of rules we used for constructing the multiple synthetic voices. In a node-finding task, participants identified the position of a previously listened-to node. Our results show that subjects recalled the nodes' positions in the hierarchy significantly better when the hierarchies were equipped with multiple synthetic voices than without.