Distances can be very deceptive in the Cape area, Ace. If you were indeed on the MI causeway you were actually 17+ miles from the pad, although I am surprised that you heard nothing at that range. At 7 miles you can hear it loud and clear. For anyone interested, the closest off-base viewing point is along the waterfront at Titusville. At around 11 miles, it is the place to be if one has no pass.
A further bit of trivia. The closest any person is allowed to be during (Shuttle) launch is 3 miles, which is at the VAB/LCC area. Inside 2 miles the shock waves can cause internal damage, and inside 1 mile it may kill you --- so goes the standard spiel. I am assured by ground crew friends that rabbits are found hopping around the pad, shortly after launch, although the subsequent acuity of their hearing has never been tested. On at least one occasion I know of, an hour after launch, a pad crew found a rat crawling along one of the gantry arms, half way up the tower, singed, disorientated but still alive. Also, no doubt, profoundly deaf!
Ace, my first ever experience of a launch and the start of my lifelong friendship with the Cape was also Apollo 17 and up at the LCC area. Were you "journoing" then, or part of a certain crew? Drop me a line!