1、 Report ITU-R BT.2207-1(05/2011)Accessibility to broadcasting servicesfor persons with disabilitiesBT SeriesBroadcasting service(television)ii Rep. ITU-R BT.2207-1 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and economical use of the radio-frequ
2、ency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by World and Regional Radiocomm
3、unication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used for the submission of pate
4、nt statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Series of ITU-R Reports (Also a
5、vailable online at http:/www.itu.int/publ/R-REP/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodetermination, amateur and related satell
6、ite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management Note: This ITU-R Report was approved in Eng
7、lish by the Study Group under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2011 ITU 2011 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rep. ITU-R BT.2207-1 1 REPORT ITU-R BT.2207-1 Acces
8、sibility to broadcasting services for persons with disabilities1(2010-2011) TABLE OF CONTENTS Page Foreword 2 1 Hearing disabilities . 3 2 Seeing disabilities . 3 3 Aging disabilities 3 4 Receiver user-friendliness 4 Annex 1 Speech, captioning and multimedia browsing technologies to improve accessib
9、ility to broadcasting services . 4 1 Speech rate conversion technology for elderly people . 4 2 Real-time closed-captioning using speech recognition 7 3 Multimedia browsing system for visually impaired people . 9 Annex 2 Machine translation to sign language with CG-animation technologies to improve
10、accessibility to broadcasting services . 12 1 Machine translation to sign language with CG-animation . 12 Annex 3 Audio processing technologies to improve accessibility to broadcasting services . 15 1 Device for evaluating broadcast background sound balance for elderly listeners . 15 1This matter sh
11、ould be communicated to the IEC and brought to the attention of ITU-T SG 16. 2 Rep. ITU-R BT.2207-1 Foreword There are 650 million people with disabilities in the world today about 10% of the worlds population and their proportion and number are growing, as humanity lives longer. A disproportionatel
12、y high number of those with disabilities are in developing countries. Television, radio, and Internet are an integral part of the fabric of society, and we cannot imagine a “full life without them. Having a disability can deny normal access to the media, and this can limit life-choices, personal ind
13、ependence, personal fulfilment, sense of identity, enjoyment, and social cohesion. In considering Resolution 70 (Johannesburg, 2008) of the World Telecommunication Standardization Assembly as well as Resolution 58 (Hyderabad, 2010) of the World Telecommunication Development Conference, on access to
14、ICT for persons with disabilities, including age-related disabilities, the ITU Plenipotentiary Conference (Guadalajara, 2010) approved Resolution 175 that instructs all three ITU sectors, inter alia, “to take account of persons with disabilities in the work of ITU, and to collaborate in adopting a c
15、omprehensive action plan in order to extend access to telecommunications/ICTs to persons with disabilities, in collaboration with external entities and bodies concerned with this subject”. The following is given in the UN Convention as an explanation of the principle of “disability”. “Persons with d
16、isabilities include those who have long-term physical, mental, intellectual or sensory impairments which, in interaction with various barriers, may hinder their full and effective participation in society on an equal basis with others”. Particularly important disabilities relevant for the media incl
17、ude: hearing disabilities; seeing disabilities; aging disabilities; cognitive disabilities; lack of controllability of the man-machine interface and ease of use of the receiver or terminal. However, the structure of the broadcasting system, language/writing system and culture, broadcast formats vary
18、 from one country to another and affect what kind of services may be delivered. The Convention does not ask that infinite resources be given over to providing services for those with disabilities, but it does call for “reasonable accommodation” for persons with disabilities. The interpretation of th
19、is is clearly a critical issue that needs much care. The Convention offers the following explanation of reasonable accommodation: “necessary and appropriate modification and adjustments not imposing a disproportionate or undue burden, where needed in a particular case, to ensure to persons with disa
20、bilities the enjoyment or exercise on an equal basis with others of all human rights and fundamental freedoms”. So, what is a proportionate burden on television, radio, and Internet to provide measures that will make it possible for those with hearing, sight, or aging disabilities to consume the sam
21、e services as those without disabilities? In other words: What is “reasonable”? Each country should establish its own accessibility programs in response to the wishes of its population with disabilities, broadcast standards, technical possibilities, resources available for investment and the managem
22、ent circumstances of its broadcasters. The ITU-R may have a role to play in promoting the technical research and development that will make it possible to provide such accessible services and that will ease the burden of doing so on broadcasters, and/or in defining necessary conditions and specifica
23、tions for broadcasting systems Rep. ITU-R BT.2207-1 3 and accessible receivers. The ITU-R also has a role to play in establishing a system for sharing worldwide the results of research and development along with information and know-how on the practical operation of accessible services. What kind of
24、 accessible broadcast services may be introduced on what timescale depends on local conditions in each country as discussed above; the following sections are intended as examples of the kind of technology that may contribute to accessible services depending on local conditions. 1 Hearing disabilitie
25、s For television viewing, the main method of making programmes accessible is by providing optional subtitles. Hearing impaired people prefer television programmes, broadcast, streamed, or downloaded which include optional subtitles in the language of the intended audience. Digital television systems
26、 have made it possible for the subtitles to be cut into the picture by a simple procedure on the remote control. For television viewing, the secondary method of making programmes accessible is by having a Signer “in screen” providing a sign language version of the audio. This can be included permane
27、ntly in the picture, or it may be possible in the future for it to be optionally cut into the picture, at the users choice, using a broadcast multimedia system. For radio listening, the main method of making programmes accessible is by providing data which allows display of speech on a receiver scre
28、en (speech-to-text conversion data). Digital radio (audio) programmes, broadcast, streamed, or downloaded, can now include data for speech-to-text display in the receiver. A text display may also be helpful for hearing impaired people to understand the radio program. 2 Seeing disabilities For televi
29、sion viewing, the main method of making programmes accessible to those with seeing disabilities is to use “audio descriptions”. These are audio passages which explain what is happening visually in the picture. They are provided on a second audio channel which is mixed in the receiver with the normal
30、 audio in natural pauses in dialogue. Audio descriptions are particularly effective with drama. Audio descriptions can also be helpful to those with aging disabilities to bring to their attention things they need to notice in the picture to follow the plot fully. 3 Aging disabilities For the elderly
31、, it can be difficult to follow the dialogue on the radio or on television because it appears to flow too quickly. The main method of making radio programmes accessible is to adjust electronically the natural silence periods in the dialogue, and thus to make the dialogue appear to be slower. For the
32、 aged, because human response times are slower, it can be valuable to add “audio descriptions” to television programmes which help the viewer to follow the story line (e.g. a voice says “notice the clock on the wall is at five oclock”) in the pauses in dialogue. Radio programmes available via Intern
33、et with several speed adjustment options may help aged listeners to understand the programmes. 4 Rep. ITU-R BT.2207-1 4 Receiver user-friendliness Receivers should be available which have users with disabilities in mind. This can be done by the inclusion of facilities that include: simple and self e
34、vident controls, which operate in a similar way on all receivers; visual and audio guides to programme selection and choice; facilities for subtitle display, signer display, and audio descriptions. It is important to note that the practicality of such features varies according to the local broadcast
35、ing system and formats, and obviously requires the cooperation of receiver manufacturers. In Annex 1 is a report on the latest studies in Japan on technologies to improve accessibility to broadcasting services. There has been a growing interest in “universal-design products” that anyone can use with
36、 ease. And with the coming of the aging society, there will be an increasing need to develop products and services while having a good understanding of the physical characteristics of people with disabilities. The radio and television the information devices most familiar to everyone have become an
37、indispensable part of daily life. A pressing issue here is how to convey broadcast information to people with disabilities. Achieving universal design in broadcasting will require a comprehensive study that examines program production techniques at the broadcasting station while also considering the
38、 ease of operating receivers, a fitting function for making viewing and listening easy for each user, etc. In Annex 2 is a report on a study on machine translation to sign language with computer-generated (CG)-animation. Annex 1 Speech, captioning and multimedia browsing technologies to improve acce
39、ssibility to broadcasting services Annex 2 Machine Translation to Sign Language with CG-animation technologies to improve accessibility to broadcasting services Annex 1 Speech, captioning and multimedia browsing technologies to improve accessibility to broadcasting services 1 Speech rate conversion
40、technology for elderly people Elderly people often find that speech in contemporary broadcasts is too fast for comfortable listening. Although the use of hearing aids could be considered as one way of compensating for hearing difficulties when listening to radio or TV programs, this would not be eff
41、ective for all hearing difficulties that afflict the elderly. At present, no hearing aid can effectively compensate for hearing difficulties in the face of rapid speaking. NHK considered the development of hearing assistance technology for the elderly specifically for listening to radio or televisio
42、n broadcasts 1. Rep. ITU-R BT.2207-1 5 The adaptive speech rate conversion function plays speech more slowly without overrunning the programs time slot while maintaining the quality of speech. Since a time delay would be accumulated if waveform expansion were applied evenly across speech, this techn
43、ology effectively shortens non-voice intervals (that is, pauses consisting of breaths or portions with only noise). It also speeds up or slows down the rate of speech delivery to model actual utterances. Time delay is gradually eliminated while maintaining a sense of slower speech 14. Slowing down t
44、he speech rate without accumulating a time delay requires an appropriate balance between contracting non-voice intervals and expanding voice intervals. Previous research investigating the relationship between a “sense of slowness” and “naturalness” reported that expanding voice intervals as much as
45、possible was effective as long as the length of non-voice intervals was maintained at a point that minimally satisfies the need for naturalness. Such technology should also be applicable to all broadcasts, including dramas and variety shows in addition to news programs and other content that consist
46、s mostly of speech. Consideration should therefore be given to handling not just speech-based information but non-voice information as well. This can be done by first observing pitch frequency (the basic frequency of speech) and calculating its signal-to-noise (S/N) ratio with background sounds and
47、then dynamically identifying voice and non-voice information in the context of actual program sounds. A practical speech rate conversion algorithm for incorporation in a receiver should do the following 34. 1. Use the S/N ratio to help identify voice intervals and non-voice intervals. 2. Allow non-v
48、oice intervals to be shortened while maintaining a time interval that does not make speech sound unnatural to the listener and allocate that deleted portion to voiced intervals. 3. Make the expansion of voice intervals variable (as opposed to uniform), placing an emphasis on expanding those portions
49、 for which an improved sense of slowness can be expected. 4. To minimize time delay accumulation, immediately suspend processing for which signal observation for longer than a certain amount of time would be required. Based on this framework, NHK developed adaptive speech rate conversion technology as shown in Fig. 1. Here, speech that can be uttered in one breath is used as a working unit. Converted speech is then realigned with original, real-time speech after a relatively long pause (non-voice interval) corresponding to the taking of
