Simple design considerations could improve access to digital radio for people with sight loss. If implemented, these design changes could not only improve access to digital radio for blind and partially sighted people but also improve usability for sighted people.
RNIB commissioned a research study to find out how blind and partially sighted people, people with dexterity problems or dyslexia use digital radios.
Please see below a list of some of the design considerations that have been identified in this research study.
General characteristics and use
General
1. The combination of the finish and the material from which the radio hardware is made of does not produce glare in the range of normal lighting conditions (eg shiny, metallic).
2. The radio hardware designed so that when a user presses any button(s) on the radio's front, the radio does not fall over.
Button characteristics
3. All buttons elicit a clear haptic (touch) click when pressed.
4. All buttons elicit an audible click when pressed.
5. No buttons are overly sensitive to the extent that they are accidentally pressed when a user is exploring the equipment by touch.
6. Any navigation type keys (arrows up/down/left and right) are shaped consistent with their function (eg triangular points).
7. Any toggle button switches between only two states (eg voice output on, voice output off).
8. Buttons to operate the most frequently used (basic) operations [power on/off/standby, volume up/down, station up/down] are more distinctive (using larger size, unique shape and/or texture) than those that operate less frequently used (advanced) operations.
9. Dial controls that operate any function use tactile markers to indicate lowest and highest position, and current position of the dial, and/or use haptic or auditory clicks as they scroll through positions.
10. Buttons/controls are rear lit (illuminated from behind) to ease identification.
Button grouping and spacing
11. No two buttons are so close in proximity that pressing one button results in the simultaneous pressing of another.
12. No button relies solely on colour to make it distinctive.
13. There is variation in size and shape of buttons across functional groups.
14. Spaces within and between functional groupings enable users to identify and navigate functional groupings by touch.
Button labels
15. Button labels contrast strongly against the background colour.
16. Button labels use lower case text.
17. Button labels use sans serif fonts (ie those without details at the extremities of characters).
18. Button labels are positioned unambiguously in relation to their respective button (either on the button or closer to their target button than to any other button).
19. All button labels are intuitive and unambiguous.
20. The function of all buttons is made clear from the user manual.
Electronic text display
21. The electronic text display uses strongly contrasting light text against dark background.
22. User is able to reverse the colour scheme on the electronic text display.
23. The electronic text display minimises the use of scrolling/flashing text - movement the user cannot control.
Notes: It is likely that less text movement will be required when the electronic text display is larger.
24. The electronic text display uses sans serif text of as large a size as feasible given display constraints.
Voice output
25. Voice output is included as a feedback option.
26. A voice output interface is used to communicate information carried on the electronic text display.
27. Where voice output is provided, the default setting is for the voice output to be active.
28. Voice output uses full words rather than spelling out words.
29. Voice output sounds like a real person's voice.
30. Voice output can be toggled on or off.
31. Different levels of voice output can be selected by the user(eg voice output can be set to basic output only, through to full menu output via voice, and additionally detailed usage instructions via voice can be selected when wanted by the user.)
32. The speed of voice output can be adjusted.
33. The voice used by the voice output can be selected by the user from a variety of voice options.
34. The voice used by the voice output can be customised by the user (ie the user can record their own voice tags).
Basic tasks
Basic tasks: Switching on
1. The 'power on/standby' button is distinguishable from the other buttons because it is either larger and/or positioned in a predictable location (top, bottom, corners), and/or is positioned noticeably farther away from any other buttons or clusters of buttons.
2. The 'power on/standby' button is labelled 'on' 'on/off' and/or uses the internationally recognised standby symbol.
3. The button label is closer to its respective button than any other button; the label is not equidistant between buttons.
4. The receiver returns to its last used state when turned on (after first use).
5. The receiver includes a 'home' button to immediately return the user to listening to the last listened to radio station if the user gets lost in menus.
Basic tasks: First time tuning
6. Radio default (factory setting) is to DAB at first use (if FM is also available).
7. A method of switching between DAB and any analogue states is used that does not rely on a toggle.
8. When a user switches between DAB and any analogue states, appropriate feedback is provided (eg voice output, beeps…, suggestions from short preference survey).
9. Radio default (factory setting) is to auto-tune at first use.
Basic tasks: Changing radio station
10. If numeric keys 1-9 are used, they should be positioned in 3 rows of numbers, with '1' at the top left and '9' at the bottom right. The '0' (zero) key should be on an additional row beneath these three rows, underneath the '8' button.
11. A number '5' button should have a raised nib as an identifier, consistent with the European Telecommunications Standards Institute (ETSI) standard for tactile identifiers ES 201 381.
12. Design feature(s) is (are) incorporated to keep users informed during delays in feedback (eg instant audio feedback when user has activated a station switch, especially to a station on a different multiplex, to fill the delay gap; examples may include beeps, white noise, voice message indicating station change in progress).
13. Design feature(s) is (are) incorporated to provide feedback when a user has pressed a button that will result in a station change; this type of feedback being unique to this function.
14. User manual/instructions (and voice output, where present) must specify whether a user needs to press a button/depress a knob to select a channel whose position has been navigated to.
Basic tasks: Changing volume
15. If two buttons are used to change volume, the volume increase button should be positioned above or to the right of the volume decrease button.
16. The volume increase/decrease buttons should be labelled 'volume', 'vol' or 'v', with '+' or 'up' and '-' or 'down' to indicate direction.
17. The volume increase/decrease buttons have tactile markings or tactile labels (not braille as this is only understood by a minority).
Advanced tasks
Advanced tasks: setting presets
1. Equipment has a function that automatically sets presets possibly via a simple process for storing presets on a 'store as preset' or 'do not store as preset' basis for available stations.
Advanced tasks: pausing
2. The equipment supports voice output of its pausing functions and menus
Advanced tasks: recording
3. The equipment supports voice output of its recording functions and menus. No other specific suggestions at present, beyond standard buttons identification and manipulation, and voice output elements (above)
Advanced tasks: using EPG
4. The equipment supports voice output of Electronic Programme Guide content. No other specific suggestions at present, beyond standard buttons identification and manipulation, and voice output elements (above)
Advanced tasks: other (eg navigating menus)
5. The equipment supports voice output of its menus.
For a complete list of design considerations with priority levels, please refer to the complete report, Are you really listening?
Best practice guidelines: text-to-speech for Digital Radio
The UK Digital Radio Action Plan has recently agreed a document that specifies text-to-speech functionality for a (broadcast) receiver with text-to-speech system. It includes what shall or may be supported by the receiver with text-to-speech system to achieve useful functionality for the user and indicates how this should be implemented.
Watch our video on Youtube
Watch our video on RNIB's YouTube channel about how digital radios can be made more usable for people with sight loss.
More information
If you have any questions about making radios more accessible for people with sight loss, please email broadcasting@rnib.org.uk or call 0303 123 9999.