I want to use OBS'S realtime noise suppression and noise gating in another app (mainly online lecture platform Echo360). I got it working using VoiceMeeter in what seems like a hacky way, but only with high latency so far.
pactl load-module module-null-sink \
sink_name=Device_Name \
sink_properties=device.description=Device_Name
pactl load-module \
module-virtual-source \
source_name=VirtualMic \
master=Device_Name.monitor \
source_properties=device.description=VirtualMic
I took the commands from one of my side projects, maybe someone will find other parts of it interesting: https://github.com/pzmarzly/mic_over_mumble
It's not well known, but it really works spectacularly well compared to those other options. For me it never has had any audible buffer underruns (unlike Lighthost), no noticeable latency (unlike SAVI and Voicemeeter, even with small buffer sizes), no problems regarding exclusive mode (unlike voicemeeter) and it works with every single application.
The UI is not terribly clear about this, but it can drive multiple devices independently, simply by adding several "Device" blocks to the configuration.
I adjusted the numbers for my setup but his were a good starting point.
Some general EQ'ing on the mic also works wonders for how well it sounds, but that's very specific to your voice and mic.
--
Another use case of Equalizer APO where it is much better than everything else is compressing game audio. Some games simply have audio that was designed without regard for hearing safety (CS:GO is a strong contender for #1 here), and this helps immensely with it.
There'a also AULab which can be used for some effects in realtime (e.g. adding reverb and redirecting to built-in audio out).