Introduction to the Project
The TCALL research project is concerned with the use of mobile telecommunications by deaf people. TCALL is funded within the LINK programme of DTI and EPSRC and by participation of the two commercial partners.
For the first time, and probably by chance, a new design and approach to telecommunications may actually be accessible to deaf people. Using the Global System for Mobile Communication, cellular phones offer many advantages for use by deaf people. The most obvious being that there is a text display window on GSM phones. Phone mobility offers immediate advantages for deaf people who have always been difficult to locate. Standard hardware means that there is already a hearing user base. Because of the competition, the start-up costs are minimal and given the right applications and services, deaf people may be able to participate at the beginning of technological implementation. This is why TCALL is so important.
TCALL has the task to examine the needs of deaf people in the telecommunications field and to set up trials of mobile solutions for these needs.
The TCALL partners are half way into their three year programme which began work in October 1995. The project includes work to extend the use of communications by text and pen based graphics, by FAX, by the video transmission of sign language and by automatic translation between text and speech.
To ensure relevance of the development work, there are continued trials with user groups in the deaf community. Further system development in the project depends on feedback from each successive round of trials. TCALL expects that its findings will influence the design of future telecommunications equipment. Thus the needs of the hearing disabled should be provided for during design and production rather than being addressed as a later stage addition to an established product.
The Five Partners are:-
The Centre for Communications Research at the University of Bristol - who are specifically providing research and system support expertise for network interface and terminal software design.
The Centre for Deaf Studies at the University of Bristol who are co-ordinating consumer research and the field trial programme.
The MicroCentre at the University of Dundee has expertise in telephone applications for people with special needs. They are looking at the application of techniques that have been developed for non-speaking people to see how they can assist deaf people to use telecommunications systems.
Orange Personal Communications Services Ltd who are providing mobile telephones and access to their telephone network for test purposes.
Portset Systems Ltd. is specifically interested in Text-to-Speech and Speech-to-Text development work in communication networks. They are producing a system to enable direct text-voice telecommunications between deaf people and hearing users. Portset Systems Ltd is also the Project Manager.
Work to date
Evaluation of Vibrating Telephone Alarms.
Deaf people able to use the visual display of GSM phones, still have problems knowing when an incoming call is arriving - for the simple reason that phones have sound based alerting devices.
As a first step, the project developed a vibrating attachment to the phone which would alert deaf people to an incoming call. Although apparently simple, the solution is not convenient. Vibrating alarms have to be worn on the body, thus limiting their size. Vibrating batteries, an option provided by the manufacturers, are effective only for those people who can "wear" the phone but are unsuited to those who keep the phone in a briefcase or handbag. Smaller clip-on alerting devices were tried and found to be partly effective although these tend to be activated by many different radio frequency signals, (including shop security systems !)
Short Message Service.
To use the economic advantages of the mobile network SMS (Short Message Service), TCALL is developing text message exchange software TEXTTALK for use on notebook and palmtop computers.
This software includes packages for sending, receiving, forwarding and logging messages. There is also an address book and facilities for message analysis. There is an abbreviation system which gets around restrictions of the 160 character limit in a standard SMS message. TEXTTALK will also permit direct user-to-user text conversations. Work is proceeding on user identification and it will be possible to display a picture of the person who is calling. The system goes into trial during 1997.
Data Exchange
TEXTTALK uses a data exchange format and can be used to send real-time messages. Data exchange is valuable for file and information transfer. Since the GSM acts as a modem for the user, it opens up the possibility of Internet access and the use of e-mail. Again this facility will be subject to field trials with deaf people during 1997.
One interesting aspect of this work is the examination of text messages themselves. One of the discoveries during the early days of direct text communication was that deaf people changed the structure of the English which they used in order to suit the modality. Text conversations are therefore rather different from spoken messages.
User Requirements
Many deaf people are unaware of the possibilities that mobile telephones offer to them. Project resources are to be used to explore, and gain a better understanding of, telephone use by the deaf. There are specific issues which arise during text calls - such as the difficulty of identifying the other user. It is these sort of user responses which are significant and need to be examined.
The interaction between the wired and wireless telephone networks.
Mobile phones are TCALL's major interest since a mobile phone enables the deaf user and the specific equipment that he needs for telecommunication to be accessible anywhere. However deaf people will still need to be able to contact other users of text phones through the Public Service Telephone Network. It is essential that a seamless connection can be made between mobile users and those on fixed systems. Initial trials indicate that in theory there should be no difficulties; however practical use in the field is often quite a different matter.
Equipment.
Orange has provided TCALL with 27 phones connected to the live DCS1800 national network. These provide facilities for development work on voice, data, fax and Short Message Service communications.
TCALL has benefited from equipment loans and donations from a number of other organisations, enabling development work with electronic notebooks to provide portable text entry systems configured to communicate through mobile phones.
Video transmission using the telephone networks.
Orange has been investigating ways to provide multi-slot packets on their telecommunication network.
For many people who have been deaf from birth, sign language is their first language and the ability to communicate in sign is a high priority for telephone use. It may be possible to achieve this with higher bandwidth and advanced compression.
Speech-to-Text and Text-to-Speech telephone server.
An extensive market study and evaluation programme for Speech-to-Text and Text-to-Speech devices has been carried out which has enabled TCALL to identify suitable solutions in TTS and STT equipment. Text-to-Speech synthesis technology is well advanced and the market offers a number of quality devices that can be customised to create individual "speaker" identities. As at late 1996, Speech-to-Text recognition is in a comparative infancy. Only recently have the extensive computer resources, which are needed to work with the many ways that people have of speaking, become available to the mass computer market.
This work forms the initial stage in development of a communications package that will enable deaf and hearing to converse using the telephone network. The intention is that text typed by a deaf respondent will be converted into voice messages using a speech synthesizer and the spoken response transcribed by a recogniser for screen display to the deaf phone user.
Dissemination & Conferences.
An important part of the work programme is to ensure our results become known, not only within the deaf community but also to appropriate industries and service providers.
Presentations have been given in several meetings including the LINK seminar in London in May 1996, where David Jackson, a research worker who is himself deaf presented the paper "Personal Communication Services for People with a Hearing Loss".
The Partners meet regularly to review individual progress within the formal project work. Our meetings also provide opportunities for discussions with Government representatives and to consider findings that influence the direction of the project. In addition to progress management, there will be presentations of working systems, discussions to co-ordinate system trials and opportunities to review the progress of researchers who have interests in the provision of telephones for the other groups.
We have discovered a user group that for the most part has little awareness of the facilities of the telephone networks and we now know that our work must also provide generally for making the deaf community aware of mobile phone facilities. Deaf people are very interested in new technology that will improve their quality of life. The demand from the deaf community for opportunities to share in test work encourages us and reflects their desire to make better use of person-to-person telecommunications, particularly as they discover it is no longer purely a medium of sound transport.
The costs of using existing text exchange and relay services are expensive relative to those costs hearing people would experience for the same sort of conversational use. We are encouraged to provide the maximum amount of message transmission for the least cost as well as to provide new opportunities for message exchange.
The Principal Targets For 1997
The University Partners will start extensive user trials of data transmission systems. They will provide the considerable technical support that is expected to be needed. TCALL hopes to see application of its development of software that will enable fast economical text exchange between deaf people using keyboard input to mobile phones.
ORANGE will continue development of multi-slot video for sign transmission including study and testing of the algorithms.
Portset Systems has in hand the production of a prototype TTS/STT switchboard-server.
Edition 20 May 1997