The goal of this paper is to describe work on the use of TANGORA—an Automatic Speech Recognizer (ASR) that was developed by the Speech Recognition Group at the Watson Research Center—as a communication device that would allow a hearing‐impaired person to communicate with hearing individuals over the telephone. In this implementation, the speech of the hearing individual is decoded by the ASR, and the output is displayed on a computer screen for the hearing‐impaired person. The general usability of this system could be limited by the degradation in TANGORA's recognition accuracy due to (1) use of public toll‐quality telephone lines (instead of high bandwidth, low‐noise communication lines) and (2) using it as a speaker‐independent system (instead of trained to recognize each user). For these reasons, the present study was aimed at understanding the effect of decoder accuracy and knowledge about the topic of conversation on the comprehension ability of the hearing‐impaired individual. The results of some su...