The project proposes a novel design for Disambiguation based chording keyboard for blinds. Results also state that there is an optimum number of words to be included in the corpus which would benefit the users by not increasing his cognitive toll. Empirically, we have found that for the Swarachakra Hindi corpus of 10,000 words, the prediction is best and most effective for the user when the corpus size consist of about 200 high frequency words. This also opens a room for further research where a general method could be implemented to find out the optimum size of corpus in any language model