Wow, great idea!
They don't even need real ones...just digital loop recordings of screaming babies. That and barking dogs....maybe hogs too.
If we truly wanted to twist the torture knife we could in addition to the sound of screaming newborns add helpful voices of advice “Your not doing that right”. “Are you sure the baby is not too cold, too hot, too wet, too hungry?” “Your only making it worse, here let me do it.”
“Did the doctor say she should be doing that?” “Did the doctor say you should be doing that.” “Let him cry.” “Never let him cry.” and the cruelest one of all.
“Sorry, I know you just got to sleep after being awake for 34 zillion hours but I need to know where do you keep the rose scented cardamom flavored with banana spice oil?” At that point the prisoner would either shoot himself or attack the guard and thus be shot. All good.