Summary of the Report on the Review and Analysis of Teletypewriter (TTY) Technology
Introduction
A teletypewriter (TTY) is a terminal that provides a text telephony service. The device provides access to the fixed telephone network and allows users, who may be deaf, hearing and/or speech impaired, to type their conversations and read back the conversation typed by another person. The fundamental requirement of a TTY is that it transfers textual information in a timely, reliable and accessible manner.There are no clear statistics on the number or types of TTYs in Australia, who the users are, or the reasons for TTY use (e.g. people with disabilities, family and friends of people with a disability, government agencies, corporations etc.).
There are anecdotal estimates indicating that there are about 10 000 to 15 000 TTYs located in Australia.
In May 2003, following a competitive tender process, the Department of Communications, Information Technology and the Arts (DCITA) contracted Network Strategies to undertake a review of TTY technology and use in Australia.
The consultancy had three main elements:
- a critical research of literature;
- the identification and compilation of existing data relating to active TTY machines and TTY usage; and
- the development of a methodology for data collection and analysis to obtain reliable information on TTYs in Australia.
The following summary of the consultant's report has been prepared by DCITA.
Please note that some material on this site includes views or recommendations of third parties, which do not necessarily reflect the views of the Commonwealth, or indicate its commitment to particular course of action.
Terms of Reference
- Conduct a review and analysis of TTY technology in Australia, including its relationship to the National Relay Service (NRS) and disability equipment programs (DEP). Undertake consultations with key stakeholders, including the NRS provider, DEP providers, and TTY equipment suppliers. The review should:
- provide a critical review of relevant literature;
- determine the compatibility of TTYs with other telecommunications equipment and technologies;
- compile existing demographic, geographic and other available data on TTY use and users;
- identify and compile where possible currently available information on the matters covered by Term of Reference 2; and
- identify gaps in currently available information in relation to the matters covered by Term of Reference 2.
- Develop a methodology for data collection and analysis to obtain further reliable information on TTY technology in Australia, including:
- numbers of TTYs in use in Australia, broken up by major user types (e.g. residential, business/government);
- type of TTYs in Australia (make, model, age and Baudot speed) and approximate numbers of each type;
- further demographic and geographic information on TTY users;
- usage patterns, such as TTY to TTY use; use of TTYs with the NRS, TTY use patterns over time and changes due to substitute technologies such as email and SMS;
- strengths and weaknesses of TTY technology from the perspective of users, equipment suppliers and DEP providers.
- Develop an implementation plan, including timelines and approximate costings, for (2).
Report Summary
Study Approach and Literature Review
The data gathered and reviewed for this project was obtained via a literature review and direct contact with a number of key stakeholders. Key stakeholders consulted included:
- Australian Association of the Deaf (AAD);
- Australian Communications Authority (ACA);
- Australian Communication Exchange (ACE);
- Communication Aid User Society (CAUS);
- Deafness Forum;
- Department of Family and Community Services (FACS);
- Optus;
- Printacall Communications;
- Sensis (formerly Pacific Access);
- Telecommunications and Disability Consumer Representation (TEDICORE); and
- Telstra Corporation Limited.
While the amount of material able to be assessed was constrained by the short timeframe of the project, there was a consensus that there was little accurate data available on the TTY market. The limited information available, was in the form of estimates provided by various sources, and often relied on some degree of personal judgement.
More information on the Study Approach and Literature Review can be found under the 'Detailed Summary' link at the bottom of this page.
The Potential Market for TTYs
It is difficult to scope the potential market for TTYs. There are limited data available on the numbers of people who are deaf or have hearing and/or speech impairment, and it is difficult to disaggregate this data further into the segment for which TTYs are a suitable communications tool. Furthermore, this data does not include access to TTYs by the wider market (such as friends and family wishing to communicate directly with TTY users, and business and government provision of services to TTY users) which would be difficult to estimate without further research.
More information on the potential market for TTYs is available under the Market for TTYs heading in the 'Detailed Summary' at the bottom of this page.
Options for Obtaining TTYs
TTYs may be purchased privately, or rented by people with disabilities at the same price as a standard telephone handset, from the two carriers that currently offer a Disability Equipment Program (DEP), Telstra and Optus.
TTYs operate over the analogue lines of the existing public switched telephone network (PSTN), and all except one of the currently available models can also operate when connected to digital lines, such as those of a digital switchboard or Private Automatic Branch Exchange (PABX) switchboard. No TTY can operate over the Code Division Multiple Access (CDMA) and Global System for Mobile (GSM) mobile networks, nor can they operate over a CDMA Wireless Local Loop (WLL) system or a Voice over Internet Protocol (VoIP) system.
More information on new technology and TTYs is available from the New Technology and TTYs heading in the 'Detailed Summary' link at the bottom of this page.
Research on how to improve the use of TTYs over various telecommunications technologies is currently being undertaken by the Australian Communications Authority (ACA), Australian Communications Industry Forum (ACIF) and Telstra.
More information on Options for Obtaining TTYs is available in the 'Detailed Summary' at the bottom of this page.
Scoping the Current Market Size
Estimates of the number of TTYs in Australia range between 10 000 and 17 000. While accurate data on the number of Disability Equipment Program (DEP) TTYs is available from the carriers, it is much more difficult to estimate the number of non-DEP TTYs.
Confidential sales data is held by Printacall (a division of All Mod Comms Pty
Ltd)-the only Australian TTY supplier since its competitor ceased operations in 1995. Printacall is also the supplier of Telstra DEP TTYs. Data is not available for TTYs provided by other suppliers prior to 1995 and it is not clear how many are still in operation.
Based on the information currently available, detailed analysis of TTY numbers to identify data, such as models, geographic location and demographic characteristics of the owner, would require considerable resources to extract. This information is likely to be more reliable for the DEP TTYs, as the carrier records are likely to remain relatively up-to-date because the customers are being charged monthly rental.
Data for non-DEP TTYs would have been collected at the time of the sale. Unless the customer records remain current (if, for example, the customer keeps in contact with Printacall for maintenance and support), there would be deficiencies in this data.
Other sources of data for non-DEP TTYs such as Sensis (formerly Pacific Access, a wholly owned subsidiary of Telstra, and the publisher of the White Pages® and the Yellow Pages® Telephone Directories), the National Relay Service (NRS), and community organisations, would not be as reliable as they would provide a fragmented (and overlapping) view of the TTY market. It would be extremely difficult to ensure complete coverage of all TTY users, with no double counting, using these sources.
More information on Scoping the Current Market Size can be found in the 'Detailed Summary' at the bottom of this page.
TTY Models
The range of TTY models currently available within Australia retail at prices ranging from $695 and $2135. The various models offer different features and characteristics. All the models are subject to the same technical compatibility issues, that is, the inability to be used over mobile networks, CDMA WLL and VoIP.
To view information on TTY models go to the 'Detailed Summary' link at the bottom of this page.
TTY Usage
No reliable data on TTY usage was found during this consultancy. Carriers are currently unable to collect data relating to TTY usage, as there is no way of determining whether any particular call is from a TTY or from other equipment. Furthermore, the carriers currently cannot identify whether a TTY is connected to any individual line.
Some qualitative and anecdotal information is available regarding TTY usage, but this has generally been obtained from samples that are of a small size or that are unlikely to be representative.
More information on TTY usage can be found in the 'Detailed Summary' at the bottom of this page.
Substitution of Alternative Services
Any information on the take-up and use of TTY substitute equipment (such as Internet based instant messengers and chat applications; fax; and SMS via mobile telephony services) tended to be either:
- anecdotal in nature;
- based on data from at least three years ago that is unlikely to still be relevant (given the developments in technology over this period); or
- obtained by methods that may not have resulted in a representative sample of sufficient size to make reliable estimates on the total market.
More information on the substitution of alternative services is available from the 'Detailed Summary' at the bottom of this page.
Proposed Methodology for Data Collection
Collection of data on the number of TTYs and TTY usage will require several different approaches.
Information regarding the number of TTYs should come, as far as possible, from the primary source of that data, being:
- in the case of DEP TTYs-the carriers that supply the equipment; and
- for non-DEP TTYs-the TTY supplier, Printacall.
This information should further be disaggregated where possible by:
- model;
- geographic location;
- customer segment (residential, business or government); and
- the disability category of the primary user.
With regard to usage, the most viable means of data collection is via user surveys. Network Strategies recommends that a questionnaire be combined with a diary to record usage over a specified time period from the primary user(s) within a household/business.
While the combined questionnaire/diary approach places a heavy obligation on the survey participants and may have some effect on the response rate, it has a number of advantages over a simple questionnaire approach:
- Most people find it extremely difficult in recalling, to even a moderate degree of accuracy, usage details over a period of time, even as recent as within the previous few days-a diary system can provide better information, if it is simple and straightforward to complete.
- Questionnaires are typically completed by only a single household member who may have little knowledge of usage by other household members-a diary located close by the TTY would enable the primary user(s) to record details of their usage.
To reduce the burden on participants, the diary could be pre-formatted with tables showing the day of the week and columns for each type of call-a user need only tick the appropriate column.
While further work is required to develop a user questionnaire, the focus of questions may include:
- demographic and geographic information on primary users;
- specifications of TTY model;
- TTY usage patterns;
- use of the NRS; and
- other telecommunications services being utilised.
- Study Approach and Literature Review
- The Potential Market for TTYs
- Options for Obtaining TTYs
- Scoping the Current Market Size
- TTY Models
- TTY Usage
- Substitution of Alternative Services
- New Technology and TTYs


