A unit selection text-to-speech synthesis system optimized for use with screen readers

Currently, unit-selection text-to-speech technology is the common approach for near-natural speech synthesis systems. Such systems provide an important aid for blind or partially-sighted people, when combined with screen reading software. However, although the overall quality of the synthetic speech achieved by such systems can be quite high, this fact alone does not guarantee a high level of user satisfaction. Many issues have to be coped with in order to fulfill users´ expectations when integrating such systems with screen reading tools aiming to assist blind users. This work describes the design and the implementation approaches for the efficient integration of this technology into screen reading environments. In particular, the issues of natural language processing, speed optimization, multilingual design and overall quality optimization are mainly addressed in this paper. In order to evaluate the resulting system, we carried out subjective assessment tests where expert users provided feedback about performance, quality and overall experience.