I live less than 5 miles from the airport, I actually work for Delta in DTW. I even know all the frequencies and wattage output for each ground operations frequencies and partly FAA tower. The highest wattage output power is 55 watts. I can sit in the employee lot which is probably maybe a half mile away and barely hear them talking on the radio.
It's all about having a decent antenna and keeping local noise (ignition noise from your car, for example) to a minimum (where you can). Having a good external antenna makes all the difference.