1 ACCEPTED SOLUTION
Hi @Hurricane,
Have had a look through the settings and nothing stands out that could cause that (that I know off) so my recommendation is to try the phone in safe mode and see if it still happens.
Turn on and use safe mode
Safe mode allows you to turn on the device with third-party apps disabled. Then you can easily uninstall apps that may be causing a conflict or software problem.
- Turn the device off.
- Press and hold the Power key past the model name screen.
- When "SAMSUNG" appears on the screen, release the Power key.
- Immediately after releasing the Power key, press and hold the Volume down key.
- Continue to hold the Volume down key until the device finishes restarting.
- Safe mode will display in the bottom left corner of the screen.
- Release the Volume down key when you see Safe Mode.
- Uninstall apps that are causing a problem.
Turn off safe mode
- Press and hold the Power key.
- Tap Restart.
This is just to see if it could be a 3rd party app causeing it, and try clearing the Cache incase to,
How to Clean App Cache on Samsung Galaxy S8 and S8+
- Open the app drawer
- Look for ‘Settings‘ and tap on it.
- Then Tap on Apps->App Manager
- Now, select the app you want to clear off the cache.
- Now tap on ‘Storage‘.
- And then tap on ‘CLEAR DATA‘ to clear its cache memory.
If you would like to perform this task for all installed applications, this can be done easily. Follow the below steps:
- From home, tap on ‘Apps‘.
- Tap on ‘Storage‘.
- Select the ‘Cached Data‘ and confirm it to clear entire cache on the Samsung Galaxy S8 and S8+.
if after all that it still doing it I say do a factory reset (make sure you have backups set up)
From Android OS
- Tap “Settings” > “Backup and reset” > “Factory data reset” > “Reset” > “Delete All“.
From Startup
- With the device powered off, press and hold “Volume Down” and “Power“.
- Continue to hold both buttons until you see the Recovery screen.
- From the recovery screen, use the “Volume Down” button to toggle the selection to “Wipe data / factory reset“.
- Press the “Power” button to select the highlighted option.
That's about all you can try (unless any one else knows of more) at this point if the noise is still there go to the retailer with the fault or visit a Samsung shop. Hope this helps you out 
