2007 PhD Thesis Final Revised.pdf - Curtin University

Figure 6.7 Vario 80 Refreshable Braille Display (Abledata, 2004c)
Hardware voice synthesizers are another output AT device, once the only
source of text-to-speech output available to blind and vision impaired computer
users. Improvements in speed and processing power of modern computers have now
led to most users opting for a software-based solution. However, many people with
vision disabilities still prefer hardware-based synthesizers because of the clarity of
voice and the reliability of the product. Such products work by converting a
graphical data stream into a text stream and outputting it to the hardware device. The
user then hears the text equivalent of the graphical information that would normally
viewed on the screen. Popular models include the DECTalk and the Artic Transport
as featured in Figure 6.8.
Figure 6.8 Artic Transport Voice Synthesizer (Artic Technologies, 2004)
The hardware devices available for blind and vision impaired users are
generally separated into two categories: input devices, such as the Braille keyboard
and output devices such as the Braille printers. The difficulty with this type of AT is
that the interaction between the input and output devices is not simultaneous. People
without vision disabilities rely heavily on simultaneous feedback to grasp the
significance of their actions and movements, such as the relationship between the
movements of a mouse being output of that moment to a screen.
In order to provide equivalent functionality to blind and vision impaired
computer users, a variety of haptic devices have been created, some of which are still
in the experimental stage of development. Haptic devices, or tactile devices as they
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