Switches

A switch is a device for controlling assistive technology for people who have difficulty with touch screen, mice or keyboards. A mouse button and keyboard keys are types of switches.

In the context of access, a switch can be used by a person with more severe and complex disabilities to control a computer or tablet device. A switch, coupled with appropriate software and hardware, can also be used to control an individual's environment (environmental control), e.g. to close and open curtains, turn a TV on and off etc.

You can use a switch to:

• Operate a toy to help develop an understanding of ‘cause and effect'.
• Access a communication aid or control a computer, tablet or phone.
• Control devices at home in conjunction with an environmental control system.
• Drive a power wheelchair.
• Play video games.

Operating a switch

Switches can be activated with your:

• head or chin,
• finger(s), arm or hand,
• knee or foot,
• voice
• eye-blink, etc.

It is important to have a proper assessment to determine the most suitable type of switch and the best access method. Our Equipment Loan Bank has a wide range of switches available for evaluation loans for up to two months.

Cause and Effect

A single switch can be used for 'Cause and Effect', i.e. the user presses or hits the switch and something happens.

Cause and effect, whether it is a switch connected to an engaging, singing toy or to a computer game with bright colourful and, noisy animations, or driving on the DriveDeck, can be the beginning of teaching important learning skills such as:

• Looking;
• Listening;
• Choosing;
• Responding;
• Identifying;
• Choosing;
• Targeting;
• Timing;
• Turn taking.

The main objective is to ‘make something happen’. This can help to promote an understanding between the ‘action’ and ‘reaction’ of pressing a switch, providing a foundation for early learning.

For example, switches might give a child control over a toy or a computer (possibly for the first time) to help them to be an active participant instead of simply passively watching.

Cause and effect can increase confidence and as learning progresses other skills can gradually be developed such as:

• Pressing and holding the switch
• Pressing and letting go (some switch adapted toys only stop ‘performing’ when the switch is released
• Pressing a second time (sometimes the reaction on screen can differ from the first press)
• Turning on and off (a cause and effect activity could be turning on music or a video and then pausing or stopping it playing)

See Ian Bean's Switch Progression Roadmap for more practical advice on using switches.

Switches and Scanning

Switch scanning is an advanced selection technique to help navigate, identify and target items. By scanning you can access more choices using your switch(es).

Switch scanning requires time and practice to develop both cognitive and physical skills to successfully achieve accurate switch scanning.

Switch scanning is usually slower than 'direct selection' with touch or eye-gaze, but it is also a reliable and controllable method of access. Professor Stephen Hawking used a single switch to operate his communication aids and write huge books, which shows what's possible with switches.

Types of switch scanning

• Single-switch scanning - sometimes called 'auto-scan' - a cursor, indicator or highlighter moves through items one at a time. When the desired item is highlighted the user activates the switch to select it.
• Two-switch scanning - sometimes called 'step scanning' - the user presses one switch to move the cursor and a second switch to select.
• Directed scanning - the user uses three or four switches, or a switch joystick, to move the cursor in several directions and then dwell select or another switch to select.
• Row-column scanning - the highlighter moves by row then by column.

Switch scanning settings

As well as the various switch scanning methods, consideration should also be given to the switch timings and settings. A slow 'scan time' is easier to use, for example, but also slower. 

• Scan time - the time it takes to move from one item to another.
• Initial scan time - some users may require a slightly longer time when the first itme is highlighted.
• Acceptance time - the amount of time a switch is held for before it selects an item.
• Repeat delay - the amount of time the switch is held down for before the item selected is repeated.

For more information on switch scanning and timing see:

• Switch access to technology, a comprehensive guide by David Colven and Simon Judge (PDF).

It is important to have an assessment carried out by an AAC or Assistive Technology specialist to identify the best switches and switch access method.

Using switches with toys and household devices

Switch operated toys have a valuable role to play in introducing the concept of ‘cause and effect', (i.e. press the switch and something nice will happen) or learning about turn-taking, to young children.

Types of switch adapted toys include:

• Turn taking,
• Mp3 players,
• Selection of animals - a singing shark, Elephant, ‘peek-a-boo',
• Tractors, train sets,
• Bubble machines,
• Popular children's characters; Fireman Sam, Minions,
• Toy versions of household goods such as hoovers and washing machines.

A number of suitable toys can be purchased from:

• Inclusive Technology
• Liberator
• Amazon

Many simple battery-operated toys can be adapted for use with a switch by using a Battery Adaptor, available from Inclusive for £11.00.

Unfortunately, an increasing number of battery-operated toys are now ‘multi-function', with the toy performing a number of different actions, and are more difficult to adapt.

Switch timer interfaces

Some children find it a challenge to hold a switch down when playing with a toy, so you should consider a Switch timer or controller unit such as the SimplyWorks Control or Dual Switch Latch Timer. These provide a timer function, where the child presses the switch and the timer keeps the toy workign for a set time, and latching, so the child can press the switch once to start the toy going, and press it again to stop it.

Household devices

It is also possible to use a switch in conjunction with a mains appliance controller such as the it-Click On or similar device to operate mains-powered devices such as:

• a fan,
• a light,
• a TV or Radio.

The mains controllers have timer and latch functions and can be motivating for people starting to use a switch.

Further Information

• Ian Bean's Switch Progression Roadmap provides practical advice and tried and tested examples of using switches in education.
• Switching to Success - a practical guide by TalkSense.
• Abletnet Action Dictionary - "a reference guide to alternative solutions that support student actions when adaptations are required for communicating, moving, learning, and/or generally engaging in the classroom".