We used an Audio Feedback System (AFS) to present some telemetric data to human operators, as auditory information in robot arm experiments with Engineering Test Satellite VII (ETS-VII). Our intention was to provide information that assists in easier and safer operation. We think that the human-machine interface presented to human operators should correspond to different tasks and to different skill levels of human operators. Fortunately, we had opportunity to assess AFS for two tasks those of a Commander and Monitor. The Commander operates the robot arm by transmitting tele- operation commands, while the Monitor checks the indications of telemetric data on a status display. During the experiment, the Commander and Monitor used a status display to check information on the robot arm. In the experiments, seven human operators, four Commanders and three Monitors, performed their respective tasks. In order to assess the effectiveness of AFS for various skill levels of human operators, an astronaut who has a very high level of skill in controlling the robot arm was included among the Monitors. In determining the effectiveness of AFS, we focuses on the eye movements of human operators. We thus used an eye mark recorder (EMR) to measure eye movements. When auditory information was given, average fixation times required to confirm telemetric data indicated on the status display were shortened except in the case of the astronaut. AFS had no effect on the astronaut's performance.