Record Video and play audio at same time ios
Couple thing you can try:
1) Play audio on the background queue:
dispatch_async(dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0)) { self.player.play()}2) Move the code you have in viewDidAppear (including prepareToPlay()) to viewDidLoad. I assume this will be a less helpful suggestions since playing is user-initiated but there is a delay between prepareToPlay() and when your audio is ready.
If you try these and the delay is still too much, you simply might have to use something other than AVAudioPlayer, such as OpenAL.