After being approached by James C. Marsters, Weitbrecht came up with a revised design for the acoustic coupler (a type of modem), which used echo suppression. In 1964, Marsters and Weitbrecht adapted used teletypewriter equipment, and Weitbrecht made the first successful teletypewriter phone call from one deaf person to another. It took several tries, until Weitbrecht's words appeared clearly: "Are you printing now? Let's quit for now and gloat over the success." Today, this type of device is known as a telecommunications device for the deaf.