Design of an embedded speech-centric interface for applications in handheld terminals

The embedded speech-centric interface for handheld wireless devices has been implemented on a commercially available PDA as a part of an application that allows real-time access to stock prices through GPRS. In this article, we have focused mainly in the optimization of the ASR subsystem for minimizing the use of the handheld computational resources. This optimization has been accomplished through the fixed-point implementation of all the algorithms involved in the ASR subsystem and the use of PCA to reduce the feature vector dimensionality. The influence of several parameters, such as the Qn resolution in the fixed-point implementation and the number of PCA components retained, have been studied and evaluated in the ASR subsystem, obtaining word recognition rates of around 96% for the best configuration. Finally, a field evaluation of the system has been performed showing that our design of the speech centric interface achieved good results in a real-life scenario.