Depending on the volume settings of the iPad that’s running the AeroCaster LIVE app, you may not hear any sound.
Use the volume buttons or Control Center on the iPad to set the volume to maximum.
To hear the entire audio mix, make sure that the [Direct Monitor] button is turned off. There will be a small amount of latency.
When the [Direct Monitor] button is turned on, you can listen to the Mic 1, Mic 2, Line In, and Headset/Onboard Mic inputs without any latency, but you will not hear any Media Sources or Satellite Camera Microphones.
More information: AeroCaster: Can I mix the audio inputted to the VRC-01, the audio input from my smartphone’s mic and the audio signal from an audio/video file on my iPad?
Note that the [Loopback] knob is disabled while using AeroCaster Live.