Thanks for responding brushfe. Below my answers.
1. The noise is like tiny cracks or tiny electric pulse (electric static noise). Not sure if that make sense sorry :(
2. It starts with noise + audio and in a min or 2 noise takes over the actual audio in my game. But in the audio positioning example project it is always noise + audio. I have 3 different audio at objects playing in parallel in my game. Currently I am trying to use audio at position instead of audio at object to see if that makes any difference.
3. The issue happens in headphone and iPad speakers.
4. To avoid interference, I did the same tests on my iPhone in different rooms, also without bluetooth. Same result with noise.
5. I am using iPad air Gen 3 and iPhone SE 2020.