think i might actually have to agree with you on this. read my post just above this one and you will see why.

Have you tried checking what pulseaudio is doing? I have had ongoing sound issues and use simultaneous output with amplifier and headphones and pulse is the goto place for enabling simultaneous output.

My wife has very sensitive hearing and hates modern films/tv shows with all their sudden crescendos, so wants the sound down very low. I like to hear the dialogue so I know what is happening in the show and don't care about the sudden loud bits in my headphones. The wife is happy for me to explain what's going on in the show's plot as she can't hear the dialogue, don't ask----I've had 49 years of this........

What is the source of your audio? HDMI audio for instance can be tricky and needs unique settings, I know, that's what I am using through my Sony amplifier.
see the pulseaudio screenshots. The image pulse2 is a truncated one because the open dialogue boxes which show all the HDMI connections disappear when focus is removed so a screenshot is not possible.
EDIT- I took a shot with my mobile and it shows the HDMI connections (all disconnected apart from one).

I can enable the system sounds from the settings manger for individual notifications. I just turn them off-they are almost as annoying as the constant beeps from my car if I leave a door open-sometimes I just want to rip out the dashboard and stamp on the bloody peizo mini speaker.......don't mention the seatbelt beeper.......

in the kde bug report that my bug report was linked to looks to be a plasma problem. one person had just installed manjaro kde and has no notification sounds. i just installed manjaro yesterday and it has no notification sounds.

Could you point the link to this bug? Excuse if you did already, but I could not find.

Well, coming back to KDE, Qt, Frameworks...

I have noted that Notifications Sound had gone away in Fedora and KDE Neon.

(It didn't happen with Mageia, Debian, openSUSE, PCLinuxOS, Mint, Slackware, Arch, Sabayon or Devuan).

And I could get it again in Fedora and KDE Neon ─ just dealing with ON / OFF button in:

System settings > Multimedia > Audio volume > Applications > Notifications sounds

In KDE Neon, I can slide volume from 0 to 100%, and it keeps new level, and it really affects Notifications sound level.

In Fedora 30 KDE, volume always go back to zero ─ but after this, it goes MUTE.

So, I just tested Mute (ON / OFF) and it worked ─ even with slide control at zero.

I am using just Panel Volume controls, now.

sure here you go

https://bugs.kde.org/show_bug.cgi?id=407397

Thank you.

My experience is similar to #14:

really no one know how to disable kubuntu from using the hdmi sound function and revert to using what is built into the mother board?

Based on what I read of this thread; you CAN play video/audio files and get sound? If I'm right in thinking that; then it's hard to see how it's a hardware problem, because you likely wouldn't be getting any sound at all in that case, same if the sound was muted in alsamixer. That leaves KDE; I take it you've been into KDE System Settings > Multimedia (under the "Hardware" sub-menu) > Audio and Video and changed the order of the audio hardware devices under "Notifications" (under "Audio Playback") ?

If not, try doing that.

I've attached a screenshot for you, just in case I'm not clear above.

See my previous post regarding pulse audio.

You may need to install it. From memory I think it's pavucontrol the menu lists it as PulseAudio volume control
That will list your various hardware audio devices, and that is the place to choose your default
device and configure it.

The alternative is to go into the various scripts and edit the files by hand, very tedious, you have to set the initial values in several different files in /lib, /etc/alsa and other assorted directories, very messy.
I reverted back to Kubuntu 18.04 as I couldn't get 19.04 to play nicely with my sound and mythtv setup.

Tony

as you can see i only have the one option under notification and that's the hdmi. it never use to be that way. under mint, neon, kubuntu, and manjaro i had the notification sounds. as you said looks to be a kde problem for witch i created a bug report for.

https://vimeo.com/358497792

@barfly decided to take one more look at pulse and clicked the playback tab and system sounds was muted there. once i unmuted them i opened multimedia again checked notification sounds and the indicator was set to where i placed it in system sounds. looks like that may have done the trick. just have to wait for or create some kind of event to know for sure. thanks for getting me to look there again. i must of missed that tab some how.

Glad to have helped, sound in linux can be a bit of a challenge. Manufacturers write drivers for Windaz and sometimes Macs, but clever people have to reverse engineer them for linux so much kudos to all those guys.
Tony.

thanks again, after my last post thought to simply open thunderbird cause i'd get a sound notification in it if they were working. low and behold we have notification sounds again. windows can be a pain with creative sound cards, luckily most of the time you can just go into device manager, remove the sound card, reboot, and once back in windows you have your sound back without loosing any of your settings.