When Marsters received a phone call, he depended on others to answer the phone and mouth the words to him so he could read lips, after which he would reply on the telephone. At the time, there was a TTY network for business, but it was too expensive for individuals. Marsters approached Robert Weitbrecht a deaf physicist of Stanford Research Institute and suggested he look into creating a device that would allow the deaf to communicate with teletypewriters across the phone lines.