Air carrier First Officer reported receiving an Aural Terrain Alert during a visual approach while clear of any terrain factors. The alert ceased before the Captain initiated an escape maneuver and elected to continue approach to a safe landing.

Narrative

While on a visual approach into Runway XX into ZZZ; we received an Aural Terrain Warning. The CA was Pilot Flying (PF) and I was Pilot Monitoring (PM); and we had been cleared for the visual approach while abeam the airport on an ATC assigned downwind heading at 4;000 ft. We had discussed the terrain in the area; and maintained 4;000 ft. until we were past the largest terrain factor of towers around 2;750 ft. on downwind. Once beyond those obstacles; the CA descended to the FAF altitude of 2;800 ft. As PM; I was closely monitoring terrain on my Navigational Display as well as my GPS location on my iPad approach plate. We were at 180 knots and on a heading to intercept the final approach course when we received an Aural Terrain Warning. We were level at 2;800 ft. and there were no visual indications on either Navigational Display of any terrain threat as well as no Radio Altimeter Reading. Since there was no terrain threat showing on the Navigational Display; we were referencing the approach plate and the highest of the terrain around us was 2.000 ft. Regardless; the Captain called 'my aircraft'; cut off the autopilot; and climbed 250 feet while beginning to execute the EGPWS maneuver; however; the alert went away before selecting TOGA; and we were then intercepting the final approach course. I had no RA readings to call out as PM since the Navigational Display did not show a threat. Since we were above the FAF altitude and above any charted or displayed terrain threats; we elected to continue the approach and landed without incident or further alerts. The largest factor here; I believe is accepting a visual approach with surrounding terrain at night. There is no company procedure prohibiting it for ZZZ; however since we did receive an aural warning; there was either an obstacle that was not shown on our charts or in our GPS database; it was registering the obstacles on the south side of the localizer as threats (though still did not show any yellow or red on the Navigational Display); or it could have been a false reading. This was a new airport for me; and if assigned again; I will request vectors to final or extend the downwind leg to the initial fix to remain at a higher altitude.Since we appeared to be clear of any terrain threats but still received an aural warning; I would suggest incorporating notes into the company pages not to descend to the FAF altitude until established on the localizer or not to accept a visual approach clearance at night. My personal plan going forward; if operating at night; will be to maintain 4;000 ft. until established on the localizer course or request vectors from ATC if they are requesting a shorter approach.