In the phone dialer app > Menu (3 dots top/right) > Settings:
Adjust the settings for Sounds and vibration in Calling accounts, and its Call status tone sub-menu.
(Tap the SIM settings at the top of Calling accounts for call forwarding etc.)
Sorry for my misunderstanding.
The notification tone for USSD messages, is that the default sound?
In Settings > Sound v Advanced > Default notification sound
It can be set to a quiet one, or 'None' - but then you have to select a specific tone for notifications in other app.
There is currently a known issue where the audio is way too loud when Dolby is enabled. The default 'Message 1' still makes me jump out of the chair even with Dolby disabled and the volume at 50% ...
USSD message sound isn't default notification sound.
I have specific notif. tone... changed it on 'none', but beep signal stays
Thanks Dark Eagle,
Got it, USSD replies come with a system beep sound.
(Dial *#21# (Call forwarding status) to test).