Effect of artificial voice feedback delay in typing and its implications for the blind user

We examined the effect of voice-feedback delay on learning to type nonsense strings on a reduced computer terminal keyboard. The results suggest that long delays (1,642 msec) affect learning of the keyboard before mastery, whereas shorter delays (841 msec) do not. With mastery, subjects learn to ignore the disruptive effects of long feedback delays. Feedback delay may nevertheless be an important human-factors issue for blind consumers who are learning to type with a voice-based system, and for hardware and software designers of systems for the blind and visually impaired.