Include the ability to speak all displayed information
Any information that is displayed to sighted users should also be available to blind users. The visual display provides information to sighted users in a number of different ways. Most of the text in the user interface contains important information that vision impaired users also need to have available to them. The use of colours, text styling or graphical images may also give important information on top of what is contained in the text. Visual layout and positioning can provide additional context that is needed to make sense of the written information. Changes to what is displayed usually also indicate something important.
Directions and techniques
Include the ability to speak any element of the visual display that provides information (high priority)
For any text or graphics displayed on screen that conveys information, that information should be made available, as far as is technically possible, in a form that can be reproduced as spoken output.
This includes most of the text and graphics displayed on screen. There are a few exceptions, such as continuously displayed company logos, images used purely for aesthetic purposes or images used to visually reinforce information already provided in text. These should not be spoken.
For example, in the screenshot shown in figure 14:
- Each of the main functions and the recommended apps is represented by an icon and a text label, e.g. "Cinema Now", "Source", "Web Browser", "Blockbuster", "Accu Weather", etc., The text label should be spoken when the item is selected.
- The icons for programmes and apps at the top of the screen under "Your videos" and "Samsung Apps" do not have text labels but are informational. An equivalent text alternative should be spoken.
- The texts "Your videos" and "Samsung Apps" are descriptive headings for the collections of items beneath them. They should be spoken.
- The screen title "SMART HUB" identifies that this is the "home screen" when first opening or returning to this screen. This should be spoken.
- The X button in the top right is a graphic meaning should close smart hub or return to viewing. This should be spoken using an approriate text alternative, depending on what it actually does in the context.
- The two dots beneath the main function icons indicate that this is the first of two screens. The left and right arrows to the sides indicate how to get to the next screen. This is information so it should be spoken when the user navigates to the first icon. This can be done by speaking an appropriate text alternative such as main functions, screen 1 of 2, press left and right arrows for previous and next screen.
Speak information that is implicit in the layout (high priority)
If the layout of elements on the screen provides important information, this should be available as speech.
For example, in a two-dimensional grid or table the meaning of the data contained in a cell depends on its row and column position, described by the row and column headers. In the example screen shot in figure 15, the row and column headers reveal that Match of the Day is on BBC 2 England starting at 10pm. This information should be available with the programme title.
Speak information that is implicit in changes (high priority)
If screen changes or transitions provide a visual confirmation that a command has been activated, this feedback is information and should be spoken. Similarly, a lack of screen change or activity may signify that a command has not been activated. This is also information that should be spoken if it is important and would otherwise not be known.
Identify elements that are visually recognisable but unnamed (high priority)
When the user navigates to a screen, functions or area of the interface is visually identifiable as a separate logical element but Does not have a title displayed on screen, this should be announced in speech if important.
An example is where the on-screen programme guide Does not have a title such as "programme guide" displayed on screen. When it appears, a sighted person may immediately identify it as the programme guide. Even in the absence of a visible title, a screen name should be spoken so that the blind user knows where they are.
Figure 16 shows a screen containing a number of logical sections. There are three sections in the top half of the screen which have titles that can be read out when the user navigates into that section "Your Videos",˜Samsung Apps" and "Recommended" A fourth section, which takes up the whole lower half of the screen and includes the main functions "Cinema Now", "Source", "Web Browser", etc. Does not have a title. When the user navigates to this section, an appropriate title should be spoken, such as main functions or main menu, even though there is no title displayed on screen.
Inform the user when there is nothing to speak (high priority)
If a screen or list is empty with no elements to speak, this fact should be spoken.
Provide spoken feedback when nothing is happening
For any delay in receiver operation of ten seconds or more for which there is no change in the onscreen notification, spoken feedback should be used to let the user know about the delay. One way of doing this is simply to repeat the displayed message periodically.
Let the user know when spoken output is not possible
In some parts of the interface it may not be possible to provide spoken output. For example, a receiver may provide spoken output of the menu system and the programme guide, but not the interactive services.
In this case, a warning message should be spoken, giving details of how to exit this section of the user interface.