In this paper, a navigation support approach for speech-only interaction based on auditory icons for room-based designs is presented, i.e. naturally occurring sounds that have a natural mapping to the system's underlying design metaphor. In contrast to many recent investigations that have focused on multi-modal or augmented reality systems, this paper concerns a unimodal speech and sound-only system. An auditory icon based prototype system for buildings maintenance support using a room-based metaphor was developed. The design was evaluated in a comparison with earcons and no-sound designs.