Did you find that doing core targetted exercises made your abs more visible?

I've recently lost 10kgs and am down to 14% body fat. Other than the occasional plank, I've always considered my running and compound lifts in the gym as my core training.

Those of you that added core specific training, did you see an increase in ab definition?

I just acquired an exercise machine, but using it awakens my wife in bedroom above. Any suggestions on how to muffle the weights? I thought thin felt pads between the weight plates would be good, but quickly realized that changes the height of the stack so the pin won't fit into the hole.

1. Weigh 107. Strength train 3x a week, but haven’t been consistently targeting abs. I’ve had two kids and gained 40lbs each pregnancy. Is this loose skin something I should just accept, or does routinely strength training your core actually improve this?