A device comprises a transcription unit for transcribing an audio message received from the air traffic control into a text message, a processing unit for extracting first indications from the text message, a transcription unit for transcribing, into a restated text message, a restated audio message transmitted by the pilot to the air traffic control after the reception of the audio message, a processing unit for extracting second indications from the restated text message, a comparison unit for comparing the first and second indications and a warning unit for transmitting a warning to the pilot if a difference between the first and second indications is detected, so as to notify the pilot that they have misunderstood the audio message from air traffic control.