Signing
On digital terrestrial television in the UK there is a legal obligation to provide signing for deaf viewers for some programmes. Sign language comprises the use of manual gestures, facial expression and body language to convey meaning. British Sign Language (BSL) is the most popular sign language in the United Kingdom, but Sign Supported English (which tends to follow the syntax and vocabulary of English) and Makaton (a simplified form of sign language sometimes used with deaf children) are also used.
Since having a signer taking up a considerable portion of the picture area can detrimentally affect the enjoyment of those viewers who don’t need the service, the preferred method of signing is to use a human signer transmitted on a separate ‘channel’, with the signer’s picture displayed in a corner of the display. Perfection would probably be to show the signer as a full resolution digital video image that can be switched on or off, adjustable in size, and positioned in various parts of the screen at the choice of the user. At the moment the amount of data available in any digital channel for signing is so restricted that this type of ‘closed’ signing (i.e. that can be switched on or off at will according to the viewer’s wishes) can only sensibly be reproduced by the use of computer generated cartoon-like ‘avatars’, and many deaf people (or perhaps more truthfully the organisations representing them), feel that this gives them a worse service than they deserve.
Improved compression and the future new DVB-T2 transmission system could provide the extra capacity to carry signing as a proper digital video signal.
Ofcom recommendations for signing include:
- BSL should be the default language for signed programmes, but Makaton and Sign Supported English may be used.
- Interpretation and voice-overs of signed programmed should be synchronised with the original speech / sign language.
- Signed programmes should be subtitled, to make it easier for people using both signing and subtitling to understand.
- The image of the signer superimposed upon the original programme should generally appear on the right hand of the screen and occupy a space no smaller than one sixth of the picture.
- Different forms of delivery may be used. For example, broadcasters may choose to use interactive services to provide a signed version of a programme simultaneously with an unsigned version. Broadcasters may also use ‘closed’ signing should this become feasible, but the requirement for accessibility precludes the use of IPTV to provide signed programmes, unless viewers are provided with the necessary equipment.
Last updated: 20.11.2009 © Copyright reserved Website design: Digital Accessibility Team