Abstract. This study investigates the use of spearcons as an auditory cue. It looks simultaneously at both performance and subjective preference of spearcons and text-to-speech (TTS). The study replicated on a mobile phone a previous PC-based study run by Palladino and Walker [1]. Performance results have been very similar to those found in the previous study, supporting the generalizability of spearcon performance from PCs to mobile phones. TTS and spearcons both provided comparable performance improvements, suggesting that spearcons do not negatively effect the design of visual and non-visual menus and may, within the right context, lead to enhanced designs. Participants gave positive performance scores to both TTS and spearcons when no visual cues were provided. Higher rankings were provided for all audio cues when Spearcons were included both in visual and non-visual conditions.

Hand motion driven human-computer interface based on novel time-invariant gesture description is proposed. Description is represented as a sequence of overthreshold motion distribution histograms. Such description utilizes information about gesture spatial configuration and motion dynamics. K-nearest-neighbour classifier was trained on six gesture types. Application for remote slideshow control was developed based on the proposed algorithm.