03-13-2017 05:40 AM
Be really careful when trying this because it might damage your hearing.
1. Plug in the headphone (in my case, the one that came with the phone)
2. Set the volume to 10 (or any value below 30)
3. Open Groove music and play some music (in my case, 256k aac format)
4. Open Camera app and take a photo.
After you hear the camera sound, the background music volume will suddenly increase to the maximum. But the volume control still shows what you've set in step 2. Doing any adjustments will restore the volume back to the normal value.