The readback/hearback procedure is a radio protocol implemented in many technical environments to minimize communication errors. This protocol requires the receiver of a verbal instruction to repeat or read back the instruction to the sender, allowing the sender to monitor and remedy any inaccuracies if required. Although this protocol ensures that the receiver has accurately heard the instruction, it does not ensure that the receiver has necessarily understood the instruction. Using a sample of Australian power control operators, the present research investigated whether the prosodic cues that listeners attend to when judging levels of uncertainty, are also used by power control operators when judging the degree to which a receiver has understood an instruction during a simulated readback/hearback radio exchange. Intonation, inter-turn delays and fillers were identified as important prosodic cues that allow listeners to detect different levels of understanding of a receiver during a readback response. The practical and theoretical implications of the outcomes are discussed.