Slowly getting better running form

Last week, while I was doing my two-hour run, I noticed I was running with very little noise. I usually make a lot of noise when I run, because I hit the ground hard with my heel and then my toe slaps the ground. This time, it seemed like I was gliding along. Instead of my usual slap, slap, slap, I was running in stealth mode, and I noticed I was hitting the ground with the flat of my heel instead of the edge of the heel. I noticed the same thing today, almost no noise as I ran -- just a swishing as the brim of my hat brushed my nylon wind breaker. During this stealth mode, I felt relaxed, as if I was floating along the path. It only lasted a few minutes and then I was back to my slap, slap, slap, but it was nice while it lasted.