Enabling the use of computers for the visually impaired, accessibility and development of a turkish syllable-based speech synthesis system

This study aims to enable the visually impaired to use computers effectively. The visually impaired can not use the computer as normal individuals do. To be able to use computers, they need improved supportive technology, and their greatest helpers are speech synthesis softwares. These softwares are not enough alone for visually impaired individuals to use the internet, since, they need accessible pages to reach the content in the Internet. Hence, both speech synthesis and accessibility issues should be taken as a whole. As for the accessibility of the Internet, given in the theoretical foundations primarily and web pages of some major companies and organizations serving in Turkey were evaluated according to the WCAG accessibility standards to examine the levels of their accessibility. The data obtained were analyzed qualitatively with the data from two different countries. As a result of the analysis, important observations were made on the level of accessibility of the Internet in Turkey. As for the issue of speech synthesis, a Turkish syllable-based speech synthesis software has been developed, providing easier and more practical method of segmentation and labeling, using parts-based, concatenative speech synthesis technique. Input text is divided into syllables and converted to audio signals with the help of Turkish spelling algorithm integrated into the software. As a result of the verification and validation studies, the quality of speech produced ranked 3,7 out of 5 in a MOS-like rating system.