The strong scent of after-shave didn't help either.

 

The relationship between horse and rider shows up through sound.  There is a creaking made by the moving leather saddle that is unmistakable.  The horse knows it and associates it with the human.  For the most part, the human understands it but doesn’t really think about it.

The smoothness of the trail, as well as its potential incline will shift the weight of the rider, and in so doing, stretch or twist the leather, resulting in the creaking sound.

On its own, the saddle is completely silent.  Even once it is on the horse, as the horse moves the sound is barely discernable.  It is only by the addition of the rider’s weight that the volume increases.

Horse + Saddle + Rider + Movement = Sound

It is this formula that prevented the Calvary from sneaking up on the Indians.

At least, that's my theory.