Dejo said what you have to do
if you are having problems trying to implement the whole program at once, implement it in parts
have is so you can just play an audio sound (assuming they will want audio play back)
then create it so they can speak and record the sound to the phone (temporarily)
then find a way to store it all the time after that
this is a help forum, what that means is you come here say your problem, say what you have tried and say why what you have tried doesn't work and say the errors, general format is
"My Problem Description"
"Code Examples"
"Error's I'm Getting"
If you do that then people will help you and tell you the correct code, or apple documentation you should be looking at
(also by telling us you are doing it for money, gives even less incentive to help, because we don't get paid for helping you!)