Page 131 - Handbook of Electronic Assistive Technology

Chapter 5 • Alternative Access Technologies 119

products now offer on-screen displays that are accessed using a touchscreen. The touch-
screen fulfils the functions of both the hardware keyboard and the mouse.
Touchscreens first started appearing on computer and assistive technologies in the
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early 1990s. Examples include Apple’s Newton and early Dynavox communication aids.
After the millennium, touchscreen technology developed rapidly, driven by the emerging
smartphone and tablet market, and touchscreens are now inexpensive, robust and reliable.
Touchscreen interfaces are fitted to a huge range of devices, from smartphones with 3.5″
screens to interactive touch tables with 84″ screens. Almost all modern ‘high-tech’ voice
output communication aids are built around computers or tablets with touchscreens.
Most modern touchscreens are capacitive and ‘multitouch’ and are activated when a
conductor, such as a human finger, touches the screen.
Touchscreen interfaces and on-screen keyboards and have some advantages over hard-
ware interfaces:
• The selection set and item size can usually be sized to give optimum access.
• They require zero operating pressure.
• The selection set may have symbols or images instead of text.
• The design and colours may be configurable.
• The vocabulary may be presented dynamically on several different selection sets.
• The touch response or access method can be adjusted.
• Touching an item directly is cognitively easier than using a pointing device such as a
mouse or trackball.

Touchscreen Accessibility Options

Users with physical challenges may have difficulties with touchscreens, and a range of
accommodations may be available. Table 5-2 lists the most common adjustments.
The touch settings offered vary across different devices, apps and software. For exam-
ple, iOS 10 for iPads and iPhones offers Hold Duration, Ignore Repeat and Select on First
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Touch and Select on Release within the Touch Accommodations settings. Currently, equiv-
alent adjustments are not, however, available on the Windows, Android or Chromebook
operating systems. Assistive technology software and apps specifically designed for voice
output communication or computer access may have touch settings built in. For example,
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Proloquo2Go, a communication app for iOS, offers Hold Duration, Select on First Touch or
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Release and visual and auditory cues. Grid 3, a communication and computer access pro-
gram for Windows, offers ‘Touch and hold to activate’ (Hold Duration) with a choice of a

5 Tobii Dynavox history: http://www.dynavoxtech.com/company/history/.
6 Use Touch Accommodations with your iPhone, iPad or iPod touch: https://support.apple.com/en-gb/
HT205269.
7 Proloquo2Go Direct Access Method: http://download.assistiveware.com/proloquo2go/helpfiles/5.1/en/#/
section/P2gSectionAccessMethodID.
8 Touch settings in Grid 3: https://thinksmartbox.com/answer/touch-settings-in-grid-3/.