In order to experience the Spatial Audio in your Theta V recordings, you need to first stitch and process the original footage and play it back via the Theta Desktop application which supports spatial audio playback.
While listening with headphones, you should clearly hear the sound fade in and out and blend as you change your view.
If you are sharing to Youtube, you must first prepare the file by using the Ricoh Theta Movie Converter. Once uploaded to YouTube, you should clearly hear the spatial audio. YouTube takes additional time to process the spatial audio, so be patient.
I think the built in mics on the Ricoh Theta V are great except that it is more susceptible to wind noise.
When you use the Ricoh Theta Movie Converter, it will convert it into a file with 3840x1920 h.264 and Linear PCM 4 channel audio. Extracting the audio tracks should be fairly straight forward then.