Ensure that information is available to users with no sight
A 2008 survey carried out by the Royal National Institute of Blind People found that television plays a pivotal role in the lives of people with sight loss. In order to benefit from the full experience of television, people without sight need an equivalent way of receiving or accessing any information that is available in a visual form to those with sight. All on-screen information is important to blind users, including channel and programme names, set-up menus, instructions, alerts and system process indicators.
I'd like to know what channel I'm looking at. If I press the number 114 on the remote control, I've no idea what channel I'm looking at.
Guidelines survey respondent.
Visual notifications are often used to inform viewers about the content of a programme before watching, such as the suitability of the content for young children. This information needs to be provided in a non-visual form for blind viewers. This information is needed either before the programme starts or, if they switch to a programme that has already started, immediately as they start watching.
A 2007 UK survey of blind and partially sighted television viewers by the Royal National Institute of Blind People (RNIB) found that people with vision impairments have difficulty using digital television equipment independently and most have not got sighted helpers. The survey revealed that even the simple task of switching channels can be difficult without spoken output:
To get from one programme to another, blind and
partially sighted people have to either use the remote control number keypad to
key in channel numbers they have memorised, or alternatively use the channel up
and down buttons, whereas sighted people can use the Electronic Programme Guide.
As digital television has many more channels than analogue television, these
tasks involve a significant mental workload. This method of navigation also
brings with it a significant margin for error: without the visual feedback
provided automatically to sighted people, a blind person who inputs an incorrect
channel number may have to wait some time before identifying the channel being
shown. This method is further complicated when new channels are added or
channels are shifted
Many of the difficulties encountered in the RNIB survey were due to users not having the information required to plan their viewing. The following quote describes a typical problem:
...it is striking that most blind and partially
sighted people have to go to considerable lengths and consult sources other than
the television to find out what programmes have audio description, whereas
sighted people can find out that information from the programme summary or the
Access to the on-screen programme guide is an essential part of television viewing. In the RNIB survey, almost 90% of those who could not see the screen said they would like an audible television guide.A 2004 survey of people with disabilities by Fain found that a spoken programme guide was deemed as important as spoken menus.
Directions and techniques
Provide spoken output of on-screen information (high priority)
The only way to make all information available to people with no vision is to have it spoken. Without spoken output, the menus, channel and programme names, programme guide, pop-up warnings and other on-screen text will always remain unavailable to blind users.
There is a cost implication to providing spoken output, although it has been implemented in standard digital television equipment. One example is the Bush Australia BHAS03 talking set top box. Text-to-speech chipsets are inexpensive relative to other digital television components, although integrating them into the equipment user interface so that the content is spoken in the right way involves careful development work. See the guidelines on spoken output for detailed information on how to do this.
Use audible signals for system processes (high priority)
If the system is going through a process such as updating, audible signals should be used to inform the user that this is happening and help them identify the process. This can be done using spoken output for those systems that have it.
Audible signals should also be provided when a pop-up message appears requiring user intervention.
Use an audible signal to identify specific types of programmes
When a new programme begins or the user changes channel, standard audible warning signals should be emitted in the following cases:
- The programme includes audio description.
- The programme has a classification regarding suitability
As an example of how parental warning codes can be delivered, Spanish law establishes uniform criteria for classification and signalling, with programmes assigned to one of six categories, each having a corresponding visual symbol which must be displayed for at least five seconds:
Specially recommended for children (optional)
Recommended for all ages
Not recommended for children under 7 years old
Not recommended for children under 13 years old
Not recommended for children under 18 years old
A standard warning tone, one second long, is provided to accompany the symbols for programs classified as recommended for children over eighteen years or X rated. This does not give the equivalent information, however. A preferred solution would be for the equipment to issue a specific, unambiguous warning for each category, using pre-recorded speech.
Give audio feedback when there is a delay in equipment operation
For any delay in equipment operation of ten seconds or more for which there is no onscreen notification, audio feedback should be used to let the user know about the delay.
This may occur during tuning for example, when a static message is displayed. Not only can a person without sight not see what is happening on screen, they also cannot see when there is nothing happening and cannot know how long to wait before they can assume that something has gone wrong.
How you could test for this
If audible signals have been included within the interface, it is important to find out whether they are effective. Tests by blind users should be carried out to assess whether the signals are noticeable and whether their meanings are recognisable and memorable.