Audacity no sound: over-ruled by other audio-applications?

My system
Linux version 4.18.16-arch1-1-ARCH
Audacity 2.3.0, installed via Arch Linux repository (pacman)

My isssue
In case Audacity is the only running audio application: audio-playback on Audacity works fine, after I have to selected the appropriate output destination (HDA ATI SB: ALC 662 rev1 Analog (hw:2.0). BUT: in the very moment, when I am opening a second audio-application such as VLC or start on Chromium a youtube video, the playback on Audicity is not working anymore. Also: the correct output-destination is not listed anymore.
So far, I have to close all applications and restart Audacity to see the correct output-destination again.

I started to read a bit about alsa and pulseaudio … but I cannot find any solution.

Thanks in advance for any support on this.

Audacity 2.3.0 is not an official release for Linux, and is known to have some pretty bad bugs. In particular, running effects that have “real-time preview” will cause Audacity to crash.
The current release for Linux is 2.2.2.
The next release will be 2.3.1 and is scheduled for Jamuary.

Most (virtually all) modern sound cards have no hardware mixing capability, so accessing directly via ALSA almost always restricts recording or playback to one application at a time. This limitation is overcome in Linux by using an additional software layer to handle multiple audio streams, resampling and mixing. On modern Linux systems this is typically done with PulseAudio, though other options including Dmix and Jack Audio System are also available.

Normally you can just select “default” or “Pulse” as the input and output devices in the device toolbar, and everything will work as expected.

Steve, thanks for your kind reply. The drop-down menu for the audio-devices in the the device toolbar contains only one entry “Alsa”. I am wondering why PulseAudio is not listed as well. Especially since, I believe to have PulseAudio installed:

[alexander@Erde ~]$ pacman -Ss pulseaudio | grep Installiert
extra/libcanberra-pulse 0.30+2+gc0620e4-1 [Installiert]
extra/pavucontrol 1:3.0+23+g335c26c-1 [Installiert]
extra/pulseaudio 12.2-2 [Installiert]
extra/pulseaudio-alsa 2-4 [Installiert]
extra/pulseaudio-bluetooth 12.2-2 [Installiert]

“ALSA” is the “host”.
“default”, “Pulse”, and some other options including “…some description…(hw:0,0)” should be available in the two “devices” boxes.

Thanks again for your quick reply. I hope you are not feeling annoyed by my replies …
Following all the entry in the drop-down menu behind the loudspeaker icon in the device toolbar:

HDA ATI SB: ALC662 rev1 Analog (hw:1,0)
HDA ATI SB: ALC662 rev1 Digital (hw:1,1)
HDA NVIDIA: HDMI 0 (hw:2, 3)
HDA NVIDIA: HDMI 1 (hw:2, 7)
HDA NVIDIA: HDMI 2 (hw:2, 8)

==> (no default or PulseAudio)

I can hear sound on my headset/loudspeaker, when “HDA ATI SB: ALC662 rev1 Analog (hw:1,0)” is selected. But this option disappears, when another audio application is also running.

Do you have pulseaudio-alsa installed?

well, I would say yes (as listed in the previous post above):

[alexander@Erde ~]$ pacman -Ss pulseaudio-alsa
extra/pulseaudio-alsa 2-4 [Installiert]
    ALSA Configuration for PulseAudio

Sorry, I missed that.
There are currently three similar topics on this forum, and all are on Arch Linux, so it is looking very likely that this issue is specific to Arch Linux.
As I don’t have an Arch Linux system, I’m resorting to searching the Internet to try and find what’s different from Debian / Ubuntu systems (that don’t have this problem). Perhaps it would be worth you asking on the Arch Linux forums (I’m running out of ideas).

Hey, Steve … first of all: thanks for your kind replies. Of course, I will also check with other forums, e.g. Arch Linux. In case I should find something helpful, I will post it here.

Again: thanks for your time, tips, hints, etc - highly appreciated!