Spatial Speaker: 3D Java']Java Text-to-Speech Converter

Text-to-speech (TTS) converters are the key components of various types of auditory displays. Such converters are extremely useful for visually impaired computer users who depend on synthesized speech read from the computer screen or directly from the web. In this paper we propose an enhancement of a Java FreeTTS speech synthesizer by adding the function of spatial positioning of both the speaker and the listener. With our module, an arbitrary text from a file or the web can be read to the user through the headphones from a fixed or changing position in space. In our solution, we combine the following modules: FreeTTS speech synthesizer, a custom made speech processing unit, MIT Media Lab HRTF library, JOAL positioning library and Creative X-Fi sound card. Although the main focus of the paper is on the design of the "Spatial Speaker", three different applications are proposed and some results of preliminary evaluation studies and user feedback are given. The entire system is developed as a single Java class which can be used in any auditory interface developed in Java.