Nomadic Radio: Speech Audio Interaction for Contextual Messaging in Nomadic Environments

This paper discusses the interaction techniques developed for Nomadic Radio, a wearable computing platform for managing voice and text-based messages in a nomadic environment. Nomadic Radio employs an auditory user interface, which synchronizes speech recognition, speech synthesis, non-speech audio and spatial presentation of digital audio, for navigating among messages as well as asynchronous alerting of newly arrived messages. Emphasis is placed on an auditory modality as Nomadic Radio is designed to be used while performing other tasks in a user's everyday environment; a range of auditory cues provide peripheral awareness of incoming messages. Notification is adaptive and context sensitive; messages are presented as more or less obtrusive based on importance inferred from content filtering, whether the user is engaged in conversation and her recent responses to prior messages. Auditory notifications are dynamically scaled from ambient sound through recorded voice cues up to message summaries. Iterative design and a preliminary user evaluation suggest that audio is an appropriate medium for mobile messaging but care must be taken to minimally intrude on the wearer's social and physical environment