I think it depends on the cat too. If they deliver in the middle of the night, no you may not hear them. Having done this for ahwile, I watch for signs like being restless, sleeping all the time, not eating much etc. I will stay up and watch them if I know they are due. All my cats so far would rather I be with them. Last night everytime I got up to get something, she would cry until I came back. If you are there when she delivers, just sit quietly and watch, if she wants to be touched, she will let you know. Just make sure she's somewhere she can't run off and hide the babies.