Me thinks the curtain is not enough to keep the sound from the back out of the first class cabin. I guess it's better than having it right next to you but this reminds me of the smoking section that started in the row in front of yours.
http://travel.msn.co.nz/airlines/news/8266298/airline-introduces-first-class-baby-ban
http://travel.msn.co.nz/airlines/news/8266298/airline-introduces-first-class-baby-ban