AVCaptureSession playback audio through headphones

I am using a RemoteIO unit along with AVCaptureSession to playback samples received from builtin or external microphone. The problem is AVCaptureSession freezes for few seconds in the startup if RemoteIO is simultaneously initialised. I want to know if there is a better and faster way to loopback samples received through AVCaptureAudioDataOutput to headphones? There is one sample code by Apple called AVCaptureToAudioUnit that uses AUGraph but it's pretty old and does not build anymore.