Install this package:
emerge -a media-sound/pulseaudio-virtualmic
If the package is masked, you can unmask it using the autounmask tool or standard emerge options:
autounmask media-sound/pulseaudio-virtualmic
Or alternatively:
emerge --autounmask-write -a media-sound/pulseaudio-virtualmic
<pkgmetadata> <maintainer type="person"> <email>coppens.matthias.abc@gmail.com</email> <name>Matthias Coppens</name> </maintainer> </pkgmetadata>