Human Factors Underlying the Design of Reading Aids for the Blind

The design of low-cost devices, which will sense and encode a printed page in such a way that the unfamiliar output can be learned, perceived, and readily understood by a blind person, poses fundamental questions about the information processing capabilities of the human brain for which there are at present no clear answers. To circumvent these difficulties at the sacrifice of low cost, machines-synthesized speech has been adopted, and a number of reading machines employing this output have been planned and are in the process of being built. Nevertheless, despite the fact that many of the fundamental coding problems will be avoided by this procedure, it must be recognized that the sighted reader achieves high reading speeds and good comprehension by means of a complex scanning strategy, and that to realize the fullest advantages of the speech medium, the blind reader will have to be capable of exercising flexible motor control over the output of his reading machine.