Switches come in all shapes, sizes and types and must be carefully matched to the needs of the user. The process of switch selection cannot be separated from the needs of individual students. The following suggestions are offered to help you begin your switch assessment planning. You will need to choose switches using the following criteria.

Switch type
Button, wobble, string, platform, tongue, finger, sound, grip, suck, blow, head.... there are many types of switch available, and the one(s) chosen should be dependent on a combination of the factors discussed in this resource.

Target area
How big does the surface area of the switch need to be for the user to operate it successfully? For example, the AbleNet Big Red switch (13cm diameter), provides a large target to hit, but also increases the risk of being knocked accidentally. A small switch, for example the AbleNet Specs switch (3.5cm diameter), may be too small a target for a child with only gross arm movements.

Feedback
Does the user need to hear a click to help them understand that they have activated the switch? Does this click draw attention away from the activity being accessed?

Sensitivity
How much pressure is the user able to use to activate the switch? Some switches need a greater amount of pressure than others. The Tash Microlight and AbleNet String switches, for example, are very sensitive, while the QED Platform switch requires greater pressure.Some switches, like the AbleNet Large Adjustable Pressure Switch, can be adjusted to operate at various levels of pressure from light to heavy.

Travel
How much active movement does the user have? Some switches are designed for large sweeping movements (eg the AbleNet Handy Switch) while others will activate with a very small movement (eg the AbleNet Jellybean switch)

Design
Most switches are made of hard material such as plastic. Some users hit their switches with some force and may appreciate a softer surface, for example the Tash Soft Switch.

Connectors
Standard switches will be fitted with either a quarter inch jack plug or a 3.5mm jack plug. Adaptors that allow you to use a large jack plug with a small jack socket and vice versa are widely available, either from the switch suppliers themselves or from most high street audio, computer or electronic retailers. There are small but increasing number of cordless switches available.

Some switch suppliers
Note that this is not a comprehensive list:

Liberator (for AbleNet) 01476 550391 www.liberator.co.uk
QED 2000 Ltd 0870 787 8850 www.qedltd.com
Cambridge Adaptive Communication (for Tash) 01223 264244 www.camad.demon.co.uk
Inclusive Technology 01457 819790 www.inclusive.co.uk
SEMERC 0161 827 2927 www.semerc.com

next >>