Personally, I don't buy the "acoustic shadow" explanation. In the O.R., Ord reports hearing sporadic cannon fire to the south. I think what happened is that Rosecrans had explained to Grant that the ground to the south of town was open, and perfect for fighting a pitched battle. Instead, Rosecrans ends up fighting a meeting engagement in rough terrain, into which both sides fed their forces piecemeal. Cannons were deployed and fired, then taken, and re-taken. Infantry took hilltops, then were driven back, then reformed out of battle, then assaulted the positions once again. Ord was expecting to hear a continuous roar of battle, instead he heard sporadic firing as if to indicate skirmishing.

I think this is a case where, like Grabau at Raymond, a scientist tries to shoehorn a scientific explanation into the battle study when there are other more logical explanations available.