[Hasimausis]

Rather than turning your application notifications off, you need to turn them all on and that will uncover which app is producing the tone.

You are a G E N I U S !!!!

This finally helps to uncover the random sound notifications. In my case it was the AliExpress app, that had order-notifications switched on in the app, but all notifications where muted in android notification settings for AliExpress.

I followed Your advice and activated all android notification settings for all apps. After some hours a sound was played and the notification bar showed a message from the AliExpress app. So I compared all former messages to my random-sound-log I created to investigate and found out, that yesterday at 10:21 three order messages in AliExpress app where sent and that was exactly what I wrote down in my log "3 sounds at 10:21".

Thank You very much!!!

[Andoid72]

I have the same problem. Found this thread while googling for a solution.

My phone is Note20 Ultra 5G. Amazing that through all these years (from the thread chain) the same problem is there with different triggers and solutions. I used to have it the last few months I was using my previous phone, Note9, then I switched to my current phone and it was gone (I transferred all my data and settings using smart switch app). Only yesterday (5-Jan-2021) I started getting the same annoying notification sound!

Some facts and trouble shooting efforts:
----------------------------------------------
1- My phone (N20 U5G) recently got the Android-11 (one UI 3) update (last few days in Dec-2020)
2- I have my notification reminder off
3- I tried switching off NFC and bluetooth
4- I tried cache reset
5- I tried switching off ALL apps notifications
6- It is NOT "technically" a notification, but it is fired through the "media" sound category. It responds to volume up/down of the "media" sounds in my volume controls
7- It sounds even when I am on a call (!!!) in my bluetooth earphone
8- When it sounds, there is absolutely nothing showing in the notification bar
9- The sound it plays does not exist on the Ringtones list, Notification sounds list, and is not a sound file in my phone's folders (as far as I have searched) !!!
10- It is seems completely random to me, as I could not associate it with any action, app, motion or time!
11- It went away when I rebooted my phone into safe mode, for as far as I have kept it under monitor

Hence I started deleting some of the applications which I use rarely or can be deleted (stickers and stuff). It is still sounding so far. I am not sure if I am on the right path.

Appreciate any suggestions. It is really annoying.

[B. Diddy]

You've already tried using the Nice Catch app to see if it shows up in the notification log there?

[Andoid72]

I think I have the app but did not think of checking it. Thanks for the advise. Let me check and I will share the results.

[Andoid72]

Yes I checked. It is not showing anything either! The sounds stopped for about 3 days after I posted my case here, then yesterday and today started to sound again!

[mustang7757]

Yes I checked. It is not showing anything either! The sounds stopped for about 3 days after I posted my case here, then yesterday and today started to sound again!

Hi, welcome to AC!

Also try in chrome and sansung internet app long press them tap info then scroll to notification and turn off for both browser

[B. Diddy]

Sometimes in this situation, all you can do is uninstall apps one by one until the problem goes away.