ISCA Archive SLaTE 2009
ISCA Archive SLaTE 2009

A spoken dialog system for learners of English

Karl Weilhammer, Catharine Oertel, Robin Siegemund, Ricardo Sá, Anton Batliner, Florian Hönig, Elmar Nöth

Current E-Learning software presents texts, pictures, audio sounds and videos to the learner, but in many cases the user interface only allows writing or clicking on items. Some more elaborate systems for foreign-language learning allow the user to interact via speech, but only provide reading or repeating pre-specified sentences. We present a spoken-dialog system for learners of English, which is designed for conversational training. The research prototype will demonstrate a hotel-reception scenario. The system plays the role of the receptionist and the user, the hotel guest at check-in. With a system like this, learners of English can prepare themselves for real-life situations before actually travelling to Britain or the US. Current speech dialog systems (e.g. for telephone banking or flight information) are tailored to perform a task very efficiently, using a fixed policy that guides the user along a strict path through the task. In foreign language learning this approach works well only for beginners. Our system is targeted towards more advanced learners and implements a different dialog strategy. In each system state the dialog manager randomly selects one of many plausible, but different system actions. This keeps the task variable and interesting for the learner, even when repeated several times.