I would appreciate specific answers to the four (4) questions below.

Also any additional educational information on this topic is welcome,
and will be rewarded by a good tip.

1.  What does current research say on prenatal education ? 

2.  Has there been any evaluation, research done on the technology
like BabyPlus http://www.babyplus.com/science/ ?

3.  Will using BabyPlus (albeit experimental maybe) have any detrimental effects ?

4.  Do fetus's hear sounds ?  Does talking to mom's tummy make dad's
(mom's) voice familiar when the baby is born ?

Regards,