OpenIndiana Distribution

Additional to this problem,
every time any application starts playing new audio
(like pausing VLC for several seconds, then resuming, Pidgin playing it's alert etc.)
, it always plays that new sound/song/audio with maximum volume set..

Not entertaining,
like while explaining to girlfriend why favorite series screamed on pause>resuming (even she now knows that OI has a bug).

Unfortunately I cannot reproduce your issue so if you do not provide more information than circumstantial the problem has zero chance to be solved.

Without asking what information to provide, it would probably be provided in another way possible to describe problem.
What information do you need or thing could be provided?

It started behaving like that (always full volume) shortly before latest OI ISO snapshot :
Every new sound made on machine is at 100% volume.

Don't know, if it's directly related, but our pulseaudio seems to be a bit broken.
gnome-volume-control, as I understand, used gstreamer to get information about devices.
mate-volume-control rely on pulseaudio.
And pactl list doesn't show audio cards.

I think this is not fixed since
- volume control can't bring volume up from default 75% (as original report suggested)
- once it is put to 100% with audioctl, volume control can't set the volume level nor remember it for any new audio playing nor remembers volume level / Volume control can only control volume level during playback.
It seemed like fixed, but once audioctl is used, it lost control over remembering volume level.

With recent changes (and no additional sound devices), it behaves normally now.

Yet Pulsaudio still can't manage OSS:
(e.g. when rebooting into older BE and using GNOME, then restart (or update?) to using MATE , 'Solaris PCm Sink is selected for output)
Workaround is to select audiohd#0 in Sound preferences for output and input.