The plane doesn’t really know how far you are from an airport, so being any distance away from a runway doesn’t affect the sound you are hearing.
The landing gear warning will come on for a few reasons.
- You have the throttles at idle
- You are close to the ground and the terrain warning system is thinking you are going to land without landing gear deployed.
- You are in a landing configuration, gear down, throttles down but landing gear is up.
- If putting the landing gear up solves the problem, you are flying with flaps up above the maximum speed for landing gear deployment.