From what I have read babies ears are developed fully by 24 weeks but some say they can hear you about 20 weeks. Outside noises (spouse and others at the 24.) All babies start kicking and moving around by week 8 and you feeling him/her at week 16 has nothing to do with the baby developing faster, you can just feel him and 16 weeks is about when you should. most first time moms don't until closer to 20 weeks but that has nothing to with the baby developing sooner.