To work around this limitation I'd suggest the horse sound be altered to 'stand out' more. Like maybe increase certain frequencies with an audio editing program so it can be heard better but not any further away than now. But IMO the thing that irritates the most about cav is not as much the hard to hear sound as it is the ease of 'lancing'. Stabbing with a long stick from horseback wasn't even a RL ability as far as I know (unless they want to end up with a broken arm trying to hold on to it).

Your saddle helped keep you on the horse, and helped absorb a lot of the blow from the lance. Also most lances had some sort of a hand plate to stop the hand from sliding up the shaft on impact (called a vamplate). And when thrusting you would have the lance braced under your forearm and against your tricep (and possibly bicep just before thrusting). While it's true that most lances were used by couching and then were not used after the initial charge (because the knights would have nowhere to go with their horse, so they'd either pull out a sword/axe/blunt/pierce weapon and start going to town from horse back or dismount and use those closer quarters weapons).
That being said, the lance tip was not designed to break off (like some tips of throwing weapons to cause more damage) or like jousting lances to prevent people from being hurt in tournament jousts. They weren't barbed to stay inside the victim like some ranged projectiles either. They were diamond point tips meant to create a large wound and be able to be pulled back out. The force would knock the person back and rip a hole in them large enough to be able to pull the lance out. If it didn't explode through a part of your body and just come out the other side.
So with all that being said, the main reason the lance was a one and done weapon (used only for the initial charge) was because the cavalry wasn't able to just pick off one person and keep on riding like in C-rpg. Typically the other infantry would be close enough that the horsemen would have nowhere to go. Also, the lancers would charge into (ideally) the flanks of the enemy, but they would charge directly into them, not parallel to their line. So they would hit them, and have nowhere to go on their horse, and the lance would be useless at that point (they used heavy and long lances, not short ones that could easily stab down at infantry underneath them).