In my professional life I attend many video conferences. We use all kinds of software, Teams, jitsi , Zoom etc. Right before entering a meeting I like to check if my microfone is working and adjust the sound level of my microphone. Using the command 'pactl load-module module-loopback latency_msec=2000'
I can create a loopback device with a delay of 2s. This way I can perform a little soundcheck taking care I do not enter a conference blasting everyones ears to pieces. As I enter this command many times a day I decided to create a little button to my Gnome workspace.
Checkt it out at:
https://gitlab.com/raginggoblin/sound-loopback-device
or
https://extensions.gnome.org/extension/7577/sound-loopback/