Broadcasting Technologies for Persons with Disabilities; Current Services and Research Activities in Japan Tohru Takagi Senior Research Engineer, Science and Technology Research Laboratories, NHK, Japan Japan Broadcasting Corporation Asia-Pacific Regional Forum on Mainstreaming ICT Accessibility for Persons with Disabilities

1. Introduction and Motivation Japan Broadcasting Corporation

3 Role of Broadcasting for Persons with Disabilities Broadcasting is very popular media for everyone to get information, knowledge, fun and so on. Broadcasters have a responsibility for transmitting their programs to viewers independently not only from regional difference but also from individual difference. Solutions for persons with disabilities; Producing TV and Radio Programs exclusively for hearing/ visually impaired person, but there are not so many Assistive procedures for various programs; such as closed- caption, overlap of sign language and audio description

Japan Broadcasting Corporation 4 Approach for Persons with Disabilities in Japan NHK started closed-captioning and audio description services in the 1980s by developing teletext and sound-multiplex broadcast of analog TV system. Digital TV system has standard slots which are applicable to closed-captioning and audio description. Ministry of Internal Affairs and Communications, Japan (MIC) has established guidelines. By the end of 2017, followings should be accomplished, (1) 100% of closed-caption including live programs (excluding technically impossible programs) (2) 10% of audio description for applicable programs

Japan Broadcasting Corporation 5 Approach for Aging Society in Japan Aging Society is progressing rapidly in Japan. 25% of the population will be elder than 65 by 2013, the worlds fastest The elderly watch TV for longer time than young people Everyones audibility and eyesight gradually and certainly degrade due to aging Especially, viewers elder than 70 often say; Newscaster speaks too rapidly and its difficult to understand! Narration or actors line is hard to catch because BGM or sound effect is too loud! Assistive procedure for elders ears is necessary

2. Current Services and the Technologies On-line live closed-captions Speech rate conversion radio manufactured by JVC in 2002 Japan Broadcasting Corporation

7 (1) Closed-Captions in Japan Production of closed-caption Off-line closed-captions for dramas from 1983 Manual transcription using PC based specialized machine to be capable of adjusting the best timing, location, color etc. On-line live closed-captions for news from 2000 Switching between speech recognition and special keyboards, Speedy and accurate captioning is required How to view the closed-captions Any digital TV set equips with a caption decoder including One Seg mobile device Rate of NHKs closed-captioned programs in %(canned programs; drama, documentary, entertainment) 49.4%(including live programs; news, sports, music show) Mobile phone with One Seg

Japan Broadcasting Corporation 8 To Increase On-Line Live Closed-Captioning Four types of captioning methods Automatic Speech recognition developed by NHK Labs. Direct method Available to Announcer and Field Reporter Applied to News, Major League Baseball Re-speak method Another speaker listens to the program and rephrases them for speech recognition Applied to Sports, Music programs Keyboards with some highly skilled operators Special stenographic keyboards Applied to news etc. Ordinary PCs keyboards Applied to Music shows MLB captions by speech recognition Re-speak method for closed-captioning

Japan Broadcasting Corporation 9 NHKs Automatic Speech Recognition Method High speech recognition performance, gender free Switching between the program sound and the rephrased speech correspond to contents Low operating cost with fewer correction operators Expanding closed-captions with the system in the near future Direct method Program sound Announcers and field reporters Re-speak method Re-phrased speech when original speech is noisy, spontaneous, emotional Switching Speech Speech recognition Language and acoustic models Text Error correction with only one or two operators On-air Closed-captions

Japan Broadcasting Corporation 10 (2) Audio Description in Japan Rate of NHKs audio description programs in % (drama, informational, entertainment) MICs Guideline It stays at 10% of applicable programs by 2017 Reason; It takes time and labor to make audio description. Script, narration and recording are performed manually by skilled staffs. New technology is expected to assist making audio description as efficiently as possible

Japan Broadcasting Corporation 11 (3) Speech Rate Conversion Conventional hearing aid device It can compensate for only elders audible degradation related to the dynamics of loudness and frequency range. Speech Rate Conversion technology (SRC) It is effective to alleviate the difficulty of hearing rapid speech. Advantages of NHKs SRC It maintains vocal pitch and quality. Furthermore, it can work within time slot of original program. Radio and TV receiver equipped with SRC-LSI Listeners can slow down the rate of speech in a program. Speeding up speech may be also useful for visually impaired person.

Japan Broadcasting Corporation 12 It Has Two Conversion Modes Original example Ordinary Mode Uniformly extended Speech is behind its original its original example Adaptive Mode Slowed at first, and gradually restored and gradually restored Pause is shortened Converted speech is synchronized with its original speech and picture example stop Good Morning everyone!Here in NHK, Pause time Good Morning everyone!

Japan Broadcasting Corporation 13 Hearing Tests by the Elderly on Adaptive Mode Materials : 3 broadcast news sentences, about 10 seconds respectively Evaluation : Method of paired comparison; Which do you hear slower, original or Adaptive mode converted speech ? Result : 80% of 60s and 70s, and more than 50% of 80s+ heard Adaptive mode is slower than original. News Sentences Number Aged 70 to 79 (N=137) Evaluation ratio Aged 80 or more (N=50) Aged 60 to 69 (N=92) Adaptive mode Same Original

Japan Broadcasting Corporation 14 Sped Up Speech by Adaptive Mode Website service of radio news with SRC; (in Japanese) Normal: original rate Slower: Ordinary Mode 1.2 times of original time slot Faster: Adaptive Mode 0.6 times of original time slot to be easier listening than 0.6 times by Ordinary Mode Hearing test by visually impaired person Visually impaired persons hope quick listening to get voice information. For easy listening, 80% of subjects supported Adaptive Mode to speed up short sentences, to 1/2 or 1/3 times of original time slot, compared with Ordinary Mode. English example English Example Same as P12 English example English example stop

3. Research Activities for Future Services Japan Broadcasting Corporation

16 NHK Labs Research Activities For Visually Impaired Persons News flash readout service using speech synthesis through data broadcast Multimedia reception presentation system For Hearing Impaired Persons Sign language using computer graphics For the Elderly Objective indicator of the best balance between speech and background sound levels fitting for elders ear, in order to produce program sounds efficiently Web Reference NHK Labs Research Activities Web Reference

Japan Broadcasting Corporation Conclusion Further research and development are necessary to improve accessibility for persons with disabilities Higher-performance method for on-line live captioning Technical breakthrough to increase of sound description Cost and manpower are important issues to broadcasters, therefore the technologies are required to reduce them. Approach for aging society Broadcasters need suitable technologies such as to assist elders auditory degradation. Digital broadcast and ICT are progressing It is expected that accessibility will be enriched by collaboration of broadcasting and telecommunication.

Thank you for your attention NHK Science and Technology Research Laboratories Japan Broadcasting Corporation