I live about 5 miles from the Lexington, KY Airport and have problems hearing ground transmissions to the aircraft on my handheld scanners unless I am withing a mile or two of the airport. The reason for this is due to the fact that the ground transmitters are very low power and will not travel far via groundwave. Being VHF (mostly around 120 to 130 MegaHertz), these low power signals will, however, travel a hundred miles or more (Line-of-Sight) to aircraft in flight. The "in-flight" plane's transmissions, also using low power, are easily heard over wide areas on most scanners as you are in a "line-of-sight" situation with a flying aircraft. The signal "footprint" of a flying aircraft increases as it gains altitude.
The advice above about getting a yagi antenna up about 50' feet, aimed right at the airport, is good advice. I can get my local airport ground transmissions very clearly thanks to an antenna up about 40 feet on my ham radio tower.
By the way, I used to live in Indianapolis (near W. 10th and County Line Road) which is much closer to the airport than you are. While even only a few miles away, the ground control transmissions were not alway very clear in that area.
Good luck.