Audio Only Export Taking WAY too Long

Hey guys...I do video depositions as part of my video business and the court reporter is asking for the audio from the video I shot. In every other video editing application I've used, exporting audio only takes a minimal amount of time. Granted this is a 6-hour deposition (I have deleted the video track), but it's still saying it's going to take 3 hours to export a WAV file. Can this be right? Am I missing something? I unchecked "export video". Thanks for any help.

Running a Mac Pro with High Sierra 10.13.3.