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 Voice Output Communication Aids |
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| Back to Resource Index | ACE Centre Revised June 2000 |
| The choice of the right VOCA (Voice Output Communication Aid) can be difficult for users, families and professionals seeking to to use them as part of a communication solution. This resource gives explains the jargon and gives an outline of the factors governing the selection and successful use of these devices. It concludes with links to manufacturer's web sites. | |
In this resource...
Background to communication devices Many advances have been made recently in the use of technology to benefit individuals with significant impairments. One area of development has been in the field of Augmentative and Alternative Communication or AAC for short. Technology has been harnessed to give people with severe speech, language and communication difficulties the opportunity to increase their successful communication with others. These devices can supplement any speech used or offer a complete alternative to speech.
Choosing a communication device There are many factors that need to be considered when making a decision about which communication device will be the most suitable for an individual. It is therefore important that an interdisciplinary team is involved in this decision-making process together with the user, family carers, teachers and therapists. It is also essential that this team has experience of the wide range of voice output communication aids that are available on the market today. Voice output communication aids can be roughly categorised as either dedicated communication aids or computer-based communication software. There is now a wide range of communication devices available on the market. Grouping them can be a difficult task. Some of the devices are so flexible that they can be set up for complex use by very competent users, but can also be set up in a simple way for a user who is just starting to use a communication device. Making contact with an experienced speech and language therapist or having an assessment at a specialist Centre can be an important step in making a decision about an appropriate communication device. Certain features of the equipment need to be taken into account when considering what communication device will be the most appropriate for an individual. If a user is ambulant, for example, the size and weight of the aid are important.
Many people who use a communication aid also have a physical disability. The position of the equipment and their positioning if they use special seating is an important consideration that must be taken into account when deciding which communication device is going to be the most suitable for an individual. Long term use of an incorrect position can mean that an individual has less voluntary control over their movements in the future.
The mounting of the communication device must be closely linked to how a user is positioned and how they access their device. The way in which a device is mounted onto a table or a wheelchair can affect how successful the user is in using that device - in certain situations a small alteration in the angle of a keyboard can have a major impact on accessing. If the user has a powered wheelchair, the aid and its mounting should not impede the user's ability to see where they are going.
By accessing we mean how a person uses the piece of equipment. This can be direct selection, where an individual has direct physical contact with the communication device to make a choice ie touching the front of a communication aid to produce a spoken message. Direct access can be achieved by any part of the body such as the toe, finger or elbow. Access may also be by indirect selection, where an interface of some kind is used between the user and the device ie a switch is pressed at an appropriate time to produce a spoken message.
The selection set is refers to the information the user is provided with in order to make choices when using a communication device. Some communication devices offer text, some offer symbols and some offer a mixture of both. The nature of the selection set offered by a device must match the abilities of the user. In a simple example, a user who was unable to spell would not consider using a communication device that offered text as the only selection set.
The way that information is displayed to the communication aid user can be crucial to the success of a communication device. Static screen devices are those devices that make use of paper-based overlays. The symbols or icons presented on the overlay can be used for identifying where single messages are stored but can also be used in series of combinations to enable the user to produce unique and complex phrases. Dynamic screen devices make use of newer technology, including touch screens. Symbols that represent single words or whole phrases are presented on a number of linked pages. The user may need to select vocabulary from a number of different pages to produce unique messages.
The long-term goals of the user are an important consideration for the team of professionals when making a decision about an appropriate communication device. This is because the device may be useful initially but the user may soon develop more advanced skills and require a much more complex device. The team needs to be able to estimate the progress the user will make in developing their skills in the future and match this up with the needs of the user in the future. The potential complexity of the communication device can also play a part in this decision. Some users of communication devices start with a simple device and then as they develop and new machines are developed they move onto using a more complex device.
When making a decision about a suitable communication device for an individual it is important to consider what output options the user is offered when they have made a selection. Some communication devices offer visual output, usually in the form of a display on a screen. Output from a device can also be auditory, usually in the form of a spoken message. The message itself may be delivered using digitised or synthetic speech. (Digitised speech is recorded human speech and synthesised speech is computer-generated). The needs of the user's communication partners can be important here as a communication device that only offers text messages displayed on a screen is only of use to a user who always communicates with people who can read.
The user may require feedback from the communication device in a number of forms: auditory, tactile, or visual. This feedback needs to be matched to the user's skills and also to their preferences. Some users, for example, may need auditory feedback to help them select the words they want, others may find that auditory feedback after each selection is useful to help reassure them that they have selected the item they wanted. However for some users this constant feedback may be annoying, especially if they often compose sentences word by word.
Some communication device users are ambulant and so the size and portability of the device is an important issue. The weight of the device is an factor for a wheelchair user who will have it mounted on their wheelchair - anything too heavy can unbalance the wheelchair and adjustments may need to be made to the weight distribution of equipment for that individual.
As can be seen from the long list above there are many considerations to be made when making a decision about the correct communication device for an individual. While all of them are important, one of the most crucial is the amount and quality of training and support that is available to the individual after a device has been purchased. The real work starts after a user receives a device for the first time. A support team composed of relevant professionals and family members is strongly recommended. Coordination of this team by one of these individuals is important so that the support is organised and communication between the group members is efficient. This needs to be ongoing support that includes regular reviews of the progress the user is making.
Training for the user and those supporting the user Some initial training may be available from the supplier or manufacturer of the communication device. This may be included in the purchase price of the equipment and may be available for all those supporting the individual and the user themselves. Other training may be purchased from the same source at a later date and may be suitable as the user's skills develop. In certain circumstances there may be opportunities for several users of similar equipment to meet up to share experiences and to pass on handy tips.
Warranty and repair service availability Extended warranties are available from the majority of voice output communication aid manufacturers. If a computer with specialist communication software is being used, a warranty may be more difficult to obtain for the whole package, unless the whole package is purchased from one supplier. Be sure to look at what the warranty covers at the time of purchase, as it could become very difficult to get the money to fund repairs, which may be minor, but mean the machine cannot be used.
Dedicated voice output communication aids New devices are continually being introduced to the market, so check the revision date at the top of this resource in case you have stored or printed an out-of-date version. The aids are divided below into three categories to help you identify which devices are particularly suitable for the individuals you are involved with. Simple Medium Complex AbleLink One Step Communicator, Liberator Ltd www.liberator.co.uk Medium complexity communication devices Alphatalker Liberator Ltd www.liberator.co.uk Axs1600 Liberator Ltd www.liberator.co.uk
Communication software - computer-based devices The factors concerning the choice of a computer based communication device are complex. Those involved in the decision making process need to find out much to do with the computer system they are wishing to use; does it have a sound card? Does it have good speakers that are powerful enough to be heard in a noisy room? Is there the right technical support available for the user to help them out if they get into difficulties.
Speaking Dynamically Pro Don Johnston Special Needs Ltd www.donjohnston.com/uk
Bliss for Windows Cambridge Adaptive Communication (CAC) www.camad.demon.co.uk
Rumble, G. and Larcher, J. (1998) AAC Device Review, VOCAtion, Marlow, UK. ISBN 095337580-3 Jans, D. and Clarke, S. (1998) High Technology Aids to Communication, in Augmentative Communication in Practice - An Introduction, Revised Edition, CALL Centre, Edinburgh ISBN 1 898042 15 2
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| © 2000 ACE (Aiding Communication in Education) Centre Advisory Trust, Oxford. Registered Charity No 1040868. Email us at info@ace-centre.org.uk | |
