Improving the quality of live TV subtitles

17 May 2013

Ofcom today announced proposals to improve the quality of subtitling on UK TV to benefit deaf and hard-of-hearing viewers.

Subtitles are used by over a million people with hearing impairments to watch TV[1]. While pre-prepared subtitling is generally of a good quality[2], viewers have made clear that there are continuing problems with the speed, synchronisation, accuracy and presentation of live TV subtitling.

Examples of errors in live subtitling

The images used below are based on actual errors in live TV programming[3]. Problems with live subtitling

Ofcom engaged with hearing-impaired viewers and bodies that represent their interests to understand their experiences of live subtitling, and also considered available research. As a result, Ofcom found that the main problems are:

  • latency - the delay between speech and live subtitling;
  • inaccuracy - mistakes that vary from minor spelling errors to major omissions or misleading subtitles;
  • intermittent subtitles, which freeze or disappear for unpredictable reasons; and

presentation - whether subtitles are shown scrolling across the screen or in more readable blocks containing one or more sentences.

To help address these issues, Ofcom has published proposals for consultation aimed at improving live subtitling to provide a better viewing experience for people who are deaf and hard-of-hearing.

Proposals to improve live subtitling

Under the current rules, TV broadcasters that attract a certain audience level must provide subtitles and they have to provide information to Ofcom on the amount of subtitling they provide[1]. While the current rules have resulted in high levels of subtitling across a range of channels, Ofcom is now proposing they also report on the quality of their subtitles.

This would help by highlighting problem areas and incentivising broadcasters to make improvements. It would also enable viewers to monitor what progress is being made by each broadcaster to improve quality of live subtitles.

Therefore, Ofcom is proposing to publish reports every six months on:

  • key measures of quality - the speed and accuracy of subtitling and the length of delays between speech and subtitling;
  • the number of programmes that are accepted later than the intended 'delivery date', resulting in live subtitling, which can be of lower quality, rather than pre-prepared subtitles; and
  • reports on technical failures that may have occurred.

Ofcom is also asking broadcasters and others for views on the feasibility of delaying live programmes for a short period of time (perhaps a few seconds) in order to improve the quality of live subtitling.

Claudio Pollack, Ofcom Consumer Group Director, said: "Ofcom wants to see an improvement in the quality of subtitling on live programmes for people who are deaf and hard-of-hearing. Our proposals will help identify the areas where broadcasters can make progress, leading to a better viewing experience over time."

Ofcom’s consultation closes on 25 July 2013. ENDS

  1. Awareness and usage of subtitling services on TV is far higher than other access services. Ofcom research found that around 7.6 million (ranges from 7 million to 8.1 million) UK adults claim to have used this service. Of these, 1.4 million (ranges from 1.2 million to 1.6 million) have a hearing impairment. A large part of subtitle usage is occasional and many subtitling users appear motivated to use the service for reasons other than to compensate for a hearing impairment.
  2. Subtitling for pre-recorded programmes is usually prepared in advance, which allows it to be synchronised to images, edited to a reasonable reading speed, and checked for errors. Subtitling for live or late-delivered programmes is prepared in real time, and can result in unavoidable delays, and increases the likelihood of inaccuracies and omissions.
  3. The live subtitling errors were broadcast on BBC Weather, and ITV's Loose Women.  The pictures have been changed but the text was broadcast as shown.
  4. Under Ofcom's Code on Television Access Services, 70 channels now provide subtitling and the amount has risen from 10% on most channels to 80% or more in 2013. If broadcasters attract a viewing share of more than 0.05% then they must provide subtitles, provided that they can meet the assessed cost by paying no more than 1% of their relevant turnover.