Experiments on the Use of the Touch-Tone R Telephone as a Communication Aid for the Deaf
John R. Nelson · Journal of Speech and Hearing Research · 1970
A series of tests are described in which a Touch-Tone 1 telephone system serves as a communication aid for the deaf. Two methods are explored for presenting visual outputs of dial manipulations. Both arrangements depend on the calling party spelling the message to the deaf receiver in a previously agreed upon code. One arrangement presents lighted digits on a representation of a Touch-Tone dial. The second arrangement displays alphanumeric characters from coding schemes used. Speed and accuracy determinations are made. Typical speeds are 4 and 8 wpm for the first and second methods respectively. Both arrangements yield comparable error percentages of less than 1% after brief learning periods are completed. These performances are achieved without special training or skill.