Technology

DeafBlind Association (NSW)

Technologies Used by People who are Deafblind

There are many technological aids which may be used by people who are deafblind. They may use technology developed for people who are blind or have a vision impairment, or for people who are deaf or have a hearing impairment, or technologies which span both as well as devices developed specifically for people who are deafblind. Which particular devices an individual may use are affected by factors including choice, appropriateness, opportunity and cost. Some of the aids which may be useful to a person who is deafblind include:

TTY(teletypewriter):

A device which plugs into the telephone line (either directly or via an audio-coupler). It has a basic typewriter keyboard and visual display (possibly including a printout). A person who is deaf can communicate with another person who also has a TTY (via the telephone line), or they can communicate with a person who has hearing via the National Relay Service (Australian Communication Exchange - ACE).

Fax (Facsimile) Machine:

As with the wider community, many people who are deaf use Fax machines to communicate with each other, business and other people who have Fax machines. People who are deafblind, but still have some residual vision, may use a Fax, writing or reading messages using large black pens or print.

E-mail:

Many people who are deaf use e-mail to communicate with each other and the general community. People who are deafblind may also use e-mail in combination with screen-reading software, screen-magnification software, Braille displays etc.

Large Screen TTY:

A device similar in concept to the conventional TTY, except it has a large screen display to enable use by people who have low vision.

Tellebraille:

A device similar in concept to the TTY, except it has a Braille display and keyboard in addition to the conventional keyboard and display. A person who is deafblind (or a person who is blind) can use this device over the telephone line in similar fashion to a conventional TTY. It also allows face-to-face communication between a person who is deafblind (using Braille keyboard and display) and a sighted person (using conventional Keyboard and display). There are a number of versions of this technology available - some providing all features mentioned, others only some.

Hearing aids :

A person who has a hearing impairment and is not totally deaf may benefit from a modern hearing aid. The instrument's profile is adjusted to match the wearer's hearing contour. The devices can take many forms; behind the ear, in the ear, bone conduction etc. Many devices include a telecoil feature which allows the user to get a cleaner signal in auditoriums fitted with induction loops (some telephones also have small induction transducers). Many hearing aids also have adaptive features, which allow the instrument to reduce impact of background noise etc, but some care can be necessary using these features if the wearer is blind. Optimal performance of the hearing aid is enhanced in one-to-one situations if the speaker is within 2metres of the wearer. If the wearer has some vision, they may also benefit from lip-reading and being able to recognise facial expressions.

Assistive listening devices:

Devices which can be useful to hearing aid users whose instrument is equipped with a telecoil feature include; buildings such as audititoriums and places of worship wired with induction loops, personal loop systems where the listener uses a reciever connected to a loop worn around the neck and the speaker uses a microphone/FM transmitter combo, or, an induction headset can be used with a personal audio device or even a computer. There are also FM and infrared systems which can be used with conventional headphones, but these devices may not take advantage of the individual contour profile in a hearing aid.

Cochlea implant:

People who lose their hearing later in life may be given a cochlea implant. This is a device which bypasses the ear and connects directly to the auditory nerve. It processes sounds (via a control box) into a stream of pulses which are passed to the auditory nerve. The stream of pulses initially sound rather different to what the wearer is used to (being compared to clicks and buzzes), but with practice wearers can hear speech quite well. Sometimes results can be disappointing. Good clinical management is essential. This technology is also used on very young children who have been born deaf . However, this is cause of considerable ethical debate amongst the deaf community.

TactAid:

With the advent of more powerful hearing aids and the cochlea implant, this device is not as common as it once was. However, it may still be an option for those who may not be suitable for a cochlea implant. Sounds are picked up and processed by a small control box which converts the signal into vibrations which are transferred to the wrist via a wrist strap. With practice, some users can learn to interpret speech patterns and environmental sounds. Earlier models had only two channels, but later models have increased the number of channels.

Slate and stylus:

Perhaps the simplest aid used by a person who is blind to Braille notes or messages. The slate is a hinged (usually metal or plastic) device, consisting of a backing plate which has a series of indentations arranged as a sequence of 2 by 3 (6 dot) cells, and, a "front" plate which has a series of rectangular openings corresponding to the cell indentations on the backing plate. The slate generally has two or more lines of cells and can be up to 40 cells wide (though 28 is more common). The stylus is a small pointed device about 50mm (2 inches) long, designed to fit comfortably in the hand. The stylus is used to produce Braille by pressing the appropriate dots in each cell to form Braille letters. This process is performed back-to-front (i.e. from right to left), in order that the text will read from left to right when the paper is turned over so the dots face upward. Many types of paper can be used, but the generally recommended weight is around 150gsm.

Perkins Brailler:

Probably the most commonly used mechanical Brailling device is the Perkins Brailler. This device is rather similar in profile and operation, to an old fashioned mechanical typewriter. Like a typewriter, it has a spacebar, a backspace key and a feed key. There are six additional keys, which are used in combinations to form the six dots of a Braille cell. All the keys to form a Braille character are held down simultaneously, when the keys are released the character is formed by the mechanism indenting the paper. The new character appears as raised dots on the paper, which are accessible immediately to the user. There are a number of devices which perform similar functions, but the Perkins is the most well known

CCTV (closed circuit TV):

A device similar in concept to a microfiche reader, except it is designed to magnify text from conventional reading material. Generally, the book (or other reading material) is placed on a movable table which is attached to the frame of the CCTV. A camera is located just above the reading material, and by moving the table the area of interest can be moved under the camera lense. The signal from the camera is fed to a TV display, which the user views the document on. Degree of magnification can be varied by positioning of the camera and (sometimes) by electronic means as well. Often the CCTV can invert the image (i.e. produce a negative image) to enhance contrast. The device allows a person with low vision to view printed documents and labels. Magnifying lenses can also be useful.

Computers:

Modern computers can be used in combination with adaptive software such as screen-readers and screen magnifiers to enhance opportunities for a person who is blind or has a vision impairment to access electronic documents and the internet etc. Screen-readers allow a person who is blind to read text in many formats by translating the text to speech or Braille - it cannot however translate graphics, though use of alternate text can mitigate this a little on web sites. Screen-magnification software can enhance viewability for people with a vision impairment by making the image larger, changing contrast or changing colour etc.

OCR (optical character recognition):

OCR can be performed on a personal computer with a flatbed scanner. This allows some blind or vision impaired users to scan documents into a computer and convert printed text into electronic format that can be read by a screen-reader or screen-magnification software. There are also a number of integrated devices which act as stand-alone book-reading machines

Braille display:

A device which displays computer generated text as a row of Braille cells. Quite an expensive device. It is very useful to a person who isdeafblind, as it allows text to be read using finger-tips when speech or magnification are not an option. It is also very useful to blind users (with hearing) when reading complex text or notations which do not translate well into speech.

Braille PDAs:

In recent years, standalone PDAs (personal data assistants) with integral Braille displays have become available. Devices such as the BrailleNote and the PacMate, provide a platform for management of many tasks, such as word-processing, addressbook, book-reader, calculator, web-browser and file management etc. Recognising the needs of people who are deafblind, manufacturers have also attempted to introduce enhancements which allow face-to-face communications in configurations similar to the Tellebraille arrangement.