Dead Time

In scanning-based assistive technology interfaces, the period during which a user must passively wait before they can make their next input action. In row-column scanning, dead time occurs while waiting for the desired row or column to be highlighted. Longer dead times reduce the effective communication rate and can cause user frustration and fatigue. Dead time is a key differentiator between scanning methods — interfaces like Nomon that allow users to click at any point during a clock rotation typically have shorter dead times than sequential scanning systems.