Access methods: touch, dwell and switch scanning
An AAC system is only as good as someone's ability to operate it. If touching a small target is hard, unreliable or exhausting, the answer is not a simpler vocabulary — it is a different access method. SayThrough has three built in, all free, on every device.
Direct touch
The default, and the fastest wherever it works: tap a button and the word is added. If touch is nearly working but not quite, adjust before abandoning it — a smaller grid size gives bigger targets, and the board can be set to speak a word the moment it is selected. Accuracy problems are very often target-size problems in disguise.
Dwell (hover to select)
With dwell, holding a pointer still over a button for a set time selects it — no click, no tap. This suits anyone driving a pointer with a head mouse, a joystick, a trackball or eye-gaze hardware, and anyone for whom the click itself is the difficult part rather than the aiming.
- Set the dwell time to the person, not to an average. Too short and the board fires words while they are still looking; too long and every sentence becomes work.
- Watch for accidental selections along the way. If words are picked up while moving across the board, lengthen the dwell time before rearranging anything.
Switch scanning
Scanning moves a highlight through the board on its own, and the person presses a switch when it reaches what they want. Any switch that presents itself as a key press will work — a button switch on a USB or Bluetooth interface, a keyboard key, a tablet's accessibility switch. It is the access method of last resort in the best sense: when almost nothing else is voluntary and repeatable, one reliable movement is enough to talk.
- Row–column scanning steps through rows first, then the cells within the chosen row. That is far fewer steps than scanning every cell in turn, and it is the standard choice on a board of any size.
- Automatic or step scanning. Automatic advances on a timer and the switch selects; step advances on each switch press, with a second switch or a dwell to select. Step is slower but removes all timing pressure.
- Scan speed is the whole game. Set it slow enough that a correct press is achievable every single time, then speed up only as reliability allows.
Allow more time than feels comfortable. The gap between the highlight arriving and the switch press has to cover seeing it, deciding, and moving — and for many people that chain is far longer than their understanding. A scan that is slightly too fast produces constant errors and looks exactly like a comprehension problem when it is a timing problem.
Choosing between them
Start with the most direct method the person can use reliably, because it is always the fastest — direct touch beats dwell, and dwell beats scanning, by a wide margin. Move down that list only when the method above it genuinely is not working, and be willing to move back up as motor skills change. An occupational therapist, or an SLP with AAC experience, is worth a great deal here; the hardware question is often theirs to answer rather than yours.
Setting it up in SayThrough
- Open Settings and find Access method.
- Choose touch, dwell or scanning, then set the timing — dwell time, or scan speed and scanning pattern.
- Test it on a whole message, not a single button. What you are checking is whether a complete sentence is achievable without exhaustion.
All three methods are included at no cost and on every device, because an access method is not a premium feature — it is the difference between an app someone can use and an app they cannot.
Try the access settings. They are available from the first moment, with no profile and no account required.