The use of Spatialized Speech in Auditory Interfaces for Computer users who are Visually Impaired

Abstract

Introduction This article reports on a study that explored the benefits and drawbacks of using spatially positioned synthesized speech in auditory interfaces for computer users who are visually impaired (that is, are blind or have low vision). The study was a practical application of such systems—an enhanced word processing application compared to conventional screen-reading software with a braille display. Methods Two types of user interfaces were compared in two experimental conditions: a JAWS screen reader equipped with an ALVA 544 Satellite braille display and a custom auditory interface based on spatialized speech. Twelve participants were asked to read and process three different text files with each interface and to collect the information about their form and structure. Task-completion times and the correctness of the perceived information on text decorations, text alignment, and table structures were measured. Results The spatial auditory interface proved to be significantly faster (3 minutes, 12 seconds) than the JAWS screen reader with ALVA braille display (8 minutes, 38 seconds), F(1,70) = 391.523, p < .001, and 15% more accurate when gathering information on text alignment, F(1,70) = 28.220, p < .001. No significant difference between the interfaces could be established when comparing questions on text decorations, F(1,70) = 0.912, p = .343, or table structures, F(1,70) = 1.045, p = .310). Discussion The findings show that the auditory interface with spatialized speech is more than 160% faster than the tactile interface while remaining equally accurate and effective for gathering information on various properties of text and tables. Implications for practitioners The spatial location of synthesized speech can be used for the fast presentation of the physical position of texts in a file, their alignment, the dimensions of tables, and the position of specific texts within tables. The quality of spatial sound reproduction can play an important role in the overall performance of such systems.