broadcasting technologies for persons with disabilities; current services and research activities in...

Broadcasting Technologies for Persons with Disabilities; Current Services and Research Activities in Japan

Tohru TakagiSenior 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


3Japan Broadcasting Corporation

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


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


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 world‘s fastest The elderly watch TV for longer time than young people Everyone’s “audibility” and “eyesight” gradually and

certainly degrade due to aging

Especially, viewers elder than 70 often say; Newscaster speaks too rapidly and it’s difficult to

understand! Narration or actor’s line is hard to catch because BGM

or sound effect is too loud!

Assistive procedure for elder’s ears is necessary

2. Current Services and the Technologies

On-line live closed-captions Speech rate conversion radiomanufactured by JVC in 2002



(1) Closed-Captions in Japan

Production of closed-caption Off-line closed-captions for “dramas” from 1983Manual transcription using PC based specialized machine tobe capable of adjusting the best timing, location, color etc.

On-line live closed-captions for “news” from 2000Switching 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 NHK’s closed-captioned programs in 2008 100%(canned programs; drama, documentary, entertainment)

49.4%(including live programs; news, sports, music show)

Mobile phone with “One Seg”


To Increase On-Line Live Closed-Captioning

Four types of captioning methods Automatic Speech recognition developed by NHK

Labs.１． Direct method

Available to Announcer and Field Reporter Applied to News, Major League Baseball

２． 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 operators３． Special stenographic keyboards

Applied to news etc.

４． Ordinary PC’s keyboards Applied to Music shows

MLB captions by speech recognition

Re-speak method for closed-captioning


NHK’s Automatic Speech Recognition Method

High speech recognition performance, gender freeSwitching between the program sound and the rephrased speech correspond to contents

Low operating cost with fewer correction operatorsExpanding closed-captions with the system in the near future

Direct method

Program sound（ Announcers

and field reporters ）

Re-speak methodRe-phrased speech

（ when original speech is noisy, spontaneous, emotional ）

Switching

Speech

Speech recognitio

n

Language and acoustic models

Text

Error correction

with only one or two

operators

On-air

Closed-captions

これまでニュースセンターに


(2) Audio Description in Japan

Rate of NHK’s audio description programs in 2008

4.0% (drama, informational, entertainment)

MIC’s 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


(3) Speech Rate Conversion

Conventional hearing aid device It can compensate for only elder’s 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 NHK’s 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.


It Has Two Conversion Modes

Original

example

OrdinaryMode

Uniformly extendedUniformly extendedSpeech is behind Speech is behind its originalits original

example

AdaptiveMode

Slowed at first, Slowed at first, andand gradually restored gradually restored Pause is shortenedPause is shortened

Converted speech is synchronized with Converted speech is synchronized with its original speech and pictureits original speech and picture

example

■stop

Good Morning everyone! Here in NHK,

PausePause

timetime

H e r e i n NHK,

Here in NHK,Good Morning everyone!

G o o d M o r n i ng everyone!


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)

Eva

luat

ion

rat

io

Aged 80 or more (N=50)Aged 60 to 69 (N=92)

Adaptive mode

Same

Original


Sped Up Speech by Adaptive Mode

Website service of radio news with SRC; http://www.nhk.or.jp/r-news/ (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”.

Englishexample

EnglishExample 　　　

Same as P12

Englishexample

English example

stop■

http://www.nhk.or.jp/r-news/



3. Research Activities for Future Services



NHK Lab’s 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 elder’s ear,in order to produce program sounds efficiently

Web Reference

Web Reference

Web Reference

NHK Lab’s Research Activities

Web Reference


4. 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 elder’s 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


broadcasting technologies for persons with disabilities; current services and research activities in...

Documents

japan production of

japan nhk

japan mic

captioning slide

speech recognition re

disabilities broadcasting

disabilities slide

original speech