Hexagonal Letter Board: A Co-occurrence Based AAC Design for Nonspeaking Spellers

This work presents a redesigned letter board for nonspeaking individuals who use Spelling to Communicate (S2C). Traditional letter boards arrange letters alphabetically, requiring the hand to travel across the entire board to spell common words — a significant barrier for spellers with motor planning challenges or limited proprioception. This design replaces the alphabetical grid with a honeycomb of hexagonal zones, each containing letters grouped by their co-occurrence frequency in English. The result is a board where common words and letter combinations fall within one or two adjacent zones, reducing hand travel to local rotation rather than full-board traversal. A dedicated YES/NO anchor zone provides consistent access to the most critical communication function. The equidistant hexagonal structure allows motor memory to develop predictably over time. With sufficient familiarity, spellers may navigate not by identifying individual letters but by tracing persistent geometric shapes — effectively developing a somatic vocabulary where words are known as movements through space. This design is offered freely to the S2C and broader AAC community under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0).