How long do the batteries last in the DS-2200?

Question: How long do the batteries last in the DS-2200?

Two AAA alkaline batteries will run the recorder in the Recording Mode for approximately 16 hours and in the Playback Mode for approximately nine hours.

Two BR-401 AAA NiMH batteries will run the recorder in the Recording Mode for approximately 12 hours and in the Playback Mode for approximately eight hours.
Verification Source: Olympus Website