Question: How do I adjust the rewind (aka smooth cue) speed on an Olympus DS-5000 Digital Voice Recorder?
Within the Olympus software, go to Tools > Options, Device Settings.
Once at the Device Settings Tab, look under Common Settings > General. At the bottom of the screen you will see Cue/Review Settings. Adjust the slider speed and click [Update] to transfer the settings to your recorder.  Be sure to uncheck the sound playback setting so it will not try to playback during rewind.
Verification Source: In-house testing & Digaulle Elhaje, Olympus Product Manager.